Ivermectin mobility in Delta del Paraná wetlands: influence of topography and soil geochemical features

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Calfayan, Olivia Suarez-Cantero, and 6 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4824566/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 31 Mar, 2025 Read the published version in Environmental Processes → Version 1 posted 11 You are reading this latest preprint version Abstract Grazing activities in wetlands ecosystems lead to the alteration of nutrients dynamics and the contamination of soils and waters with veterinary products, among other negative impacts. The objective of this work was to determine the presence and mobility of Ivermectin (IVM), an antiparasite compound used in livestock, in soils from three cattle fields located in the lower Delta del Paraná. Its mobility was correlated with the content of iron, different fractions of organic matter (OM) and clays. Results indicated that upper and middle zones of fields contained the highest content of clays and hematite (1.51 and 0.35 g/kg, respectively) and presented the highest amount of labile OM (3.70 and 2.93%, respectively), with 23.50 and 14.25 ppm of IVM, respectively. The low and anaerobic zone with high iron content (25 g/kg) and no hematite, presented 16 ppm of labile OM and 16.06 ppm of IVM. Results suggested a high mobility of IVM from upper to lower zones; and a high concentration of soluble IVM in the lower zones (2.87 ppm) compared to the upper topographies (0.45 and 1 ppm). The presence of this drug was strongly influenced by its interaction with the type of OM and the mineralogical composition of soils. This is the first time that IVM was reported to be associated to a mobile and soluble fraction of organic matter, representing a threatening situation to water courses. This study allowed to explain the occurrence and fate of the contaminant in wetlands accordingly to the physicochemical characterization of soils. Antiparasitic drugs wetlands livestock soil organic matter Figures Figure 1 Figure 2 Article Highlights - High concentrations of ivermectin found in Delta del Paraná wetland´s soils - 23.50 ppm of ivermectin in upper zones and around 15 ppm in lower and midhill zones - 2.78 ppm of soluble ivermectin found in lower zones increasing risk of ivermectin entering to water courses 1. Introduction Over the past few decades wetlands have suffered of a significant loss across the globe being degraded by climate change and human activities. The grazing activities in these ecosystems have increased significantly due to the expansion of the agricultural frontier, so an increase in the number of animals and engineering works for water management (channelling and dykes) were observed. Although cattle with open access to riparian zones of floodplain lakes can contribute to nutrients dynamics in soils (by manure input or sediment movement by cattle activity) (Mesa et al. 2015 ), the effect of this activity in subtropical floodplain wetlands is scarcely known (Sigua 2010 ). Among the negative impacts, alteration of nutrients dynamics and the contamination of soils and waters with veterinary products were mentioned (Wang et al. 2019 , Mesa et al. 2020 ). In Delta del Paraná wetlands in Argentina, grazing constitutes one of the traditional productive activities. Previous studies in the middle Delta found accumulation of the antiparasite ivermectin (IVM) in aquatic assemblages, soil, sediments, plants and manure (Mesa et al. 2020 ); as 80 to 98% of the drug is estimated to leave the animal, without being metabolized, in faeces (Ren et al. 2022 ). The risk of the presence of IVM in the environment relies on its high phytotoxic effect (Vokřál et al. 2019 ) and also causes high toxicity in invertebrates (Verdú et al. 2018 ), even for those that inhabit sediments (Lofrano et al. 2020 ); being able to disrupt the balance of aquatic populations and harm non-target species (Mesa et al. 2020 ). The persistence of IVM can lead to long-term accumulation and affecting the aquatic biodiversity (Verdú et al. 2018 ). However, reports of IVM in the environment are scarce. In Argentina, concentrations near 1 ppb were previously reported in water courses near agricultural areas (Mesa et al. 2020 , Peluso et al. 2023 ). Additionally, a previous study indicated alterations in the biomarkers of oxidative stress and neurotoxicity when exposing Rhinella arenarum larvae to 1.25 ppb of IVM and a lethal concentration for those amphibians of 47 ppb (Cui et al. 2023 ). The mechanisms through which these contaminants reach different environmental compartments and accumulate, i.e. in soils, are related to their mobility, whereas this will depend on their solubility, the type of soil, oxygenation conditions, percentage and stability of the organic matter present (Ingerslev y Halling-Sorensen 2001, Krogh et al. 2009 ) and the hydrological regime. In fact, dissipation half-lives (DT50) in soil can be rather variable depending on soil type, sorption capacity, temperature, and oxygen availability, ranging from 16 to 1520 days. IVM can be also very persistent in mixtures of soil and manure or faeces (7-217 days) (Zhao et al. 2023 ). However, the degree to which abiotic factors influence veterinary drugs accumulation in productive soils on a large scale remains poorly understood (Mishra et al. 2018 ). One of the most important abiotic factors governing organic pollutants persistence is organic matter. There are many reports indicating that pharmaceutically active compounds were protected against degradation or mobilization through adsorption on soil organic matter (Henderson et al. 1984 , Baldock y Skjemstad 2000, Ji et al. 2023 ). However this association will be more or less stable depending on the chemical nature of the soil organic matter and the soil mineral matrix. Iron oxides, clays and multivalent cations offer mechanisms of protection to organic matter, additionally to the chemically intrinsic recalcitrance of the different organic matter structures such as O -Alkyl C, Alkyl C, phenolic or aromatic (Baldock y Skjemstad 2000). Additionally to these complex protection mechanisms, soil redox conditions also influence the exposure of organic matter to biological oxidation. Due to the wetlands changing hydrology regimes, important redox processes take place playing a fundamental role in the cycling of nutrients (OC, N, P) (Dubinsky et al. 2010 , Mesa et al. 2015 ) or elements such as Fe or Al (Bhattacharyya et al. 2018 ). Particularly, iron mineral particles have a preservative effect on organic matter through direct adsorption on their surfaces in oxidic conditions, whereas in anoxic micro-environments, OM becomes susceptible to degradation by iron reducing bacteria, resulting in the solubilisation of both low molecular weight OM and Fe(II). Contrarily, clay minerals protect adsorbed organic matter while conditions are anaerobic as their surface cannot be reactive to microbial oxidation or reduction. Thus, the stability and/or mobility of the veterinary drugs that enter a wetland ecosystem will be subjected to the dynamics of these organo-mineral associations. Particularly, it has been reported that IVM can be associated to OM and can be accumulated in soils (Liebig et al. 2010 ) as well as it can present a high dissipation coefficient in aerobic conditions (Krogh et al. 2008 ). This evidence reinforces the need for a comprehensive study of organic matter, soil components, and redox conditions in the study area in order to determine the bioavailability and possible environmental risk of Ivermectin. Therefore, the objective of this work was to analyse the presence and mobility of Ivermectin in relation to the physicochemical characteristics of different types of soils and topography from fields of the lower non-insular Delta del Paraná. This study will help to understand the occurrence and fate of the IVM, in wetlands with grazing activities, accordingly to the physicochemical characterization of soils and will help to evaluate the risk of using IVM in these type of ecosystems. 2. Materials and methods 2.1. Sampling sites Three cattle fields located in the area of Delta del Parana wetlands were studied (Figure S1 , A, Supplementary material). Fields were indicated as S, C and R. The establishments were located in the area of ​​Ceibas, Villa Paranacito and Ibiquy (Fig. 1 ). Soil samples were taken from each field in the different topographies: upper, lower, and midhill areas; at 0–15 cm depths using a hand auger. The upper, midhill or lower areas of the fields correspond to the topography of the wetland; being the dry area, the hydrological-regime dependent area and the flooded area, respectively (Figure S1 , B, Supplementary material). Four samples were taken at each site and topography, and mixed to have an integrated sample. Samples were air-dried at room temperature, crushed, and passed through a 2 mm sieve to separate and discard the coarse stone fragments. These soil samples were used for the laboratory analysis, including density fractionation. 2.2. Characterization of soils 2.2.1. Iron Content Iron (Fe) environments were studied by Mössbauer spectroscopy. This technique was employed to identify Fe 3+ and Fe 2+ sites in soil samples. The 57 Fe Mössbauer spectra were recorded at room temperature using a transmission geometry spectrometer with constant acceleration. The spectrometer utilized a 57 CoRh source with a nominal activity of 50 mCi. The velocity calibration was performed using the 57 Fe Mössbauer spectrum of a 12 µm-thick α-Fe foil, which was measured under the same conditions as the samples. The isomer shifts (δ) were then referenced to this standard. All the spectra were analyzed using a program that considers the static distributions of quadrupole splitting and hyperfine magnetic fields (de Souza y Guimarães 2022). The total Fe concentration was calculated using the fitted spectrum and the method proposed by Montes (Liebig et al. 2010 ). 2.2.2. Mineralogy For mineralogical analysis by X-ray diffraction (XRD), the tuff samples were first air-dried and then stove-dried at 60°C. The determination of the mineral phases was made on random powders using a Phillips-PW3710 (Ni-filtered CuKα, 35 Kv, 40 Ma, without secondary monochromator). Samples were analyzed from 3° to 70°2θ, with a step width of 0.04° for 2 s, giving a step scan of 1°2θ/min. The determination of the clay minerals was performed on the fraction less than 2 µm on air dried oriented aggregates (2°2θ – 32°2θ), ethylen glycol solvated (2°2θ − 30°2θ) and calcined at 550°C for 2 h (3°2θ − 15°2θ) using a Bruker D2 Phaser. For the qualitative determination of the mineral phases the programs X'Pert Higscore Plus, for whole rock, and OriginPro 8, for the fraction less than 2 µm were used. The semi-quantitative determination of the mineral phases: Quartz (Qz), Alkali feldspar (Afs), Plagioclase (Pl), Smectite (Sme), Illite (I), Kaolinite (Kln) and Chlorite (Chl), was performed on the whole rock diagrams using the SiroquantTM program. 2.2.3. Relevant soil functional groups The most relevant functional groups in soils were analyzed using Fourier-transform infrared transmission spectroscopy (FTIR). The measurements were conducted using a Thermo Scientific Nicolet FT-IR 6700 instrument with a resolution of 4 cm − 1 . KBr was used as a background. First, the samples were dried at 60 ºC, and KBr was dried at 100 ºC for 24 hours. The samples, all having the same mass, were diluted 1:100 using the dried KBr. The mixture was grounded, placed in a pellet stainless steel holder, and pressed with a hydraulic press at 10 bars. Each FTIR spectrum was based on 128 scans in the range of 4000 − 400 cm − 1 . 2.2.4. Organic matter Total volatile solids (TVS) was performed by calcination of the dried samples for 3 hours at 550ºC. Organic matter (OM) was determined by the Walkley and Black method (Navarro et al. 2022 ). To predict C mineralization and to evaluate the leaching of dissolved organic matter (WSOM), the following procedure was performed (Liu et al. 2019): 20g of soil simple was stirred with 100 ml of water at 200 rpm during 1 hour, at ambient temperature (Poeplau et al. 2015 ). The sample was centrifuged and the supernatant was separated in a 10ml and a 90 ml aliquots. Total organic carbon was measured with a Total Organic Carbon analyser in the 10ml aliquot. The rest of the supernatant was used to assess the presence and content of IVM (referred as WSIVM). The procedure for the Light fraction of the organic matter (LF_OM) was adapted from Kooch et al. (Liu et al. 2019) and Dhillon et. Al. (Severini et al. 2018 ): 10g soil was agitated in 25ml of NaI (1.8g/cm3) for 60 min at 200 rpm. Then, the sample was centrifuged 15 min at 3600 rpm and the supernatant was filtered through a glass fibre membrane (0.7 um pore diameter). Sample on the filter was washed with 100 ml of distilled water followed by 25 ml of a CaCl 0.01M solution. Membranes were dried at 45ºC for 24 hours and the LF_OM fraction was determined by weight. The percentage value of LF_OM indicates the amount of labile organic matter as the fraction of the total amount of organic matter. 2.3. Ivermectin Analysis The method for the extraction of IVM and quantification from experimental samples and quantification of IVM by HPLC analysis was performed as in (Peluso et al. 2023 ) by duplicate. Briefly, samples were weighed and homogenized with the internal standard abamectin, PESTANAL® and acetonitrile (1g/ml). The preparation was incubated in agitation for 15 min and then sonicated for 20 minutes at ambient temperature. The solvent-sample mixture was centrifuged at 3500 g for 15 min. For the quantification of the IVM in the water soluble fraction of the soil (WSIVM), a portion of the aqueous extract from the organic matter fractionation was used. The supernatant or the aliquot of the aqueous extract described in the previous section was filtered through a solid-phase extraction (C18 SPE) cartridge and eluted with 100% acetonitrile (HPLC-MS quality). IVM concentrations were determined by HPLC-MS using a Thermo Scientific Ultimate 3000 equipped with an autosampler. HPLC analysis was undertaken using a reverse phase C18 column (Hypersil Gold, USA, 1.9 µm, 2.1 mm × 50 mm) and a 5 mM NH 4 AcO with 0.05% Acetic acid/Acetonitrile (25/75) mobile phase at a flow rate of 0.2 ml/min at 30°C. IVM was detected with a mass detector (ThermoScientific LTQ XL). Calibration curves were constructed in the range of 10 to 1000 ug L − 1 . The correlation coefficients of calibration curves were > 0.99. 2.4. Data Analysis To resume the physicochemical characteristics of the soils and the amount of IVM, of the different sites and topographies, a Principal Component Analysis (PCA) was made on the correlation matrix (Dhillon y Rees 2017). The sites where described by means of the inorganic (Fe, Sme, I, Kln, Chl), organic features (OM, WSOM, LF_OM, TSV, N); and the IVM and WSIVM, differentiating the three topographies. As for this analysis we need a complete data matrix without missing values and all quantitative data, in the case of non-detection of some compounds, we assigned a zero value and in the case of detection but non-quantification, we assigned the middle value between the non-detection and detection limits (table S1 ). To study the correlation between the accumulation of IVM and its mobility (WSIVM) with some interesting physicochemical variables, Pearson’s correlation tests were made. For the mid-hill of the site C there was an error in the quantification of IVM and WSIVM, so this case was not taken into account for the analysis. All the analysis were made with R software (Wang et al. 2022 ). For the PCA, the “vegan” package was used (Murad y Cashion 2004). 3. Results and discussion 3.1. Geochemical features In this study, we examined various sites (S, R, and C) across the different topographies to assess soil physicochemical parameters and IVM. Table S1 (Supplementary material) shows the results obtained for inorganic and organic characterization of the soils of the different topographies at each studied site. With the data obtained from table S1 , PCA plots were performed in an attempt to order the sites according to the soil features found in each one. Results are depicted in Fig. 1 . With the first two axis of the PCA, 63.43% of the total variability of the data could be explained (Fig. 1 ). When analysing the behaviour of variables with the topography it is noteworthy to mention that upper sites (black dots, Fig. 1 ) are mainly ordered on the first principal axis. This axis is associated to a gradient of contents of IVM, clays (Sme, Kln), iron compunds (Fe, Hematite),WSOM and N. Negative values on this axis represent a high content of IVM, clays and iron; and less content of N. Meanwhile, midhill (red dots) and lower sites (green dots) are mainly ordered on the second principal axis. This axis is associated to a gradient of contents of OM, WSOM, WSIVM, LF_OM, TSV and N. Positive values on this axis represent a high content of LF_OM, WSOM, TSV and N. Negative values on this axis represent high content OM and WSIVM. The IVM on soil was more related to upper sites; whereas WSIM was more related to the midhill and lower sites (sites in a more frequent contact with water, according to the hydrological regime). Regarding the presence and amount of Chl and I clays, they presented low amounts in all sites. As expected, these two clays behaved independently to the rest of the variables. As a summary, results indicated that IVM was related to the upper sites and could be influenced by mineralogical features of soils; whereas WSIVM was more related to midhill and lower sites and could be influenced by the different fractions of the organic matter of the soil. 3.2. Accumulation and mobility of IVM in relation to soil characteristics As described by the PCA results, to discuss the occurrence and mobility of IVM among topographies, it is important to analyse it in terms of the organic matter variables: OM, LF_OM and WSOM; and the diverse physicochemical parameters, together with the IVM and the WSIVM contents. Data was resumed by topography in Table 1 . IVM and WSIVM were found in all sites (Table S1 , supplementary material); however its distribution was not homogenous among sites as will be discussed further. IVM was slightly higher in the upper sites with a value of 23.50 ± 13.86 ppm; and WSIVM was highest in the lower topography presenting a value of 2.87 ± 0.41 ppm (Table 1 ); coincidently with the PCA results. Table 1 Mean and standard error for ivermectin and soil’s physicochemical characteristics for each topographic type. IVM, Ivermectin; WSIVM, Water soluble Ivermectin; OM, Organic matter; LF_OM, Light fraction_Organic matter; Fe, Total Iron; TSV, Total Solid Volatiles; N, Nitrogen Topography Lower Midhill Upper IVM (ppm) 16.06 ± 8.91 14.25 ± 9.05 23.50 ± 13.86 WSIVM (ppm) 2.87 ± 0.41 0.45 ± 0.45 1.00 ± 0 OM (%) 7.37 ± 2.97 2.27 ± 0.74 6.03 ± 0.92 LF_OM (%) 1.77 ± 0.61 2.93 ± 1.08 3.70 ± 1.42 WSOM (ppm) 21.67 ± 11.26 14.02 ± 13.97 21.01 ± 13.05 Fe (g/kg) 25.00 ± 5.20 14.00 ± 5.57 27.67 ± 17.15 Hematite (g/kg) 0 0.35 ± 0.35 1.51 ± 0.76 TSV (%) 15.10 ± 7.97 14.23 ± 5.77 10.83 ± 5.27 N (%) 0.73 ± 0.56 0.36 ± 0.24 0.11 ± 0.09 All the studied samples revealed the presence of two Fe 3+ sites, one Fe 2+ site and one site of paramagnetic relaxation. These signals could be associated to common clays present in soils, including Sme, I and Kln as major clays minerals (Liebig et al. 2010 ) as also showed by XRD studies (table S2, supporting information). The paramagnetic relaxation site agrees with the relatively low Fe concentration in the studied soils and could be related to Kln presence (Fang et al. 2023 ). Hematite was found predominantly in upper sites with values ranging from 0.35 to 1.51 g/kg, and total Fe concentrations varied significantly across all sites, ranging from 2 to 59 g/kg (Table 1 ). The lower and upper sites had a similar amount of Fe content, regardless that hematite was not found in lower sites. This could be impacted by the presence of iron reducing bacteria in the lower and anoxic areas, which degrade organic matter while reducing and solubilizing Fe from iron oxides (Rancourt 1998 , Poggenburg et al. 2018 ). This caused that the lower areas presented the lowest values for LF_OM (1.77%) compared to the mid-hill and upper topographies (2.93 and 3.70%, respectively); as anoxigenic conditions were favoured by the presence of water (Lalonde et al. 2012 ). Despite the high content of iron, and the presence of iron reducers in the lower topographies, total OM presented the highest value in this area (7.37%) as Sme are also present in the lower sites and they still play an important role in the protective dynamic equilibrium of soil organic matter (Schweizer et al. 2019 ) regardless of the iron concentration (Baldock y Skjemstad 2000). Regarding the amount and correlation between IVM and OM, in the lower areas there was a negative trend but not significant association (r= -0.7678505; p-valor = 0.4427; figure S2, A, Supplementary material). Negative associations have been reported for certain veterinary drugs such as antibiotics in soils (Mishra et al. 2018 ). On the other hand, the upper topography presented a positive correlation for IVM vs OM (r = 0.9999436; p – valor = 0.006764), which could be indicating a stronger association between OM and IVM for upper areas and lighter associations between these variables in lower areas (figure S2, A, Supplementary material); as also observed in the PCA results. Results indicated that the presence of IVM in the upper sites is influenced mainly by Fe, clay minerals and WSOM. This could be related in part to the drier conditions of this sampling point compared to the lower sites, favouring the oxygenation of the soil and thus generating a protection of the IVM by the Fe oxides content (Lalonde et al. 2012 ). The IVM found in the lower sites can be explained by the presence of clays and OM (Parks et al. 2021 ). This last observation is coincident with a report where the persistence of IVM under anaerobic conditions was observed (Krogh et al. 2009 , Rice et al. 2017 ). Also, it was reported that pharmaceuticals with similar structures may also behave differently and that the factors governing their mobility in sediments were unclear (Al-Khazrajy et al. 2018 ). It is noteworthy that the amount of IVM in the lower areas is still considerable compared to the other topographies (Table 1 ) as the cattle frequently enters the water course for drinking or refreshing and there is a leaching of IVM from the higher areas of the field; causing IVM to accumulate in the lower areas of the wetlands. The tendency of fewer presence of IVM in the mid-hill and lower sites, could be due to the low values of LF_OM in those sites that generates a higher degradation or mobility of IVM through the environment, as previously reported for other similar pollutants (Marco-Brown et al. 2021 ). Additionally, the upper sites has higher amounts of LF_OM compared to the values found for the other sites; which could be contributing to the mobility of pollutants through leaching, thus supporting our statement. A previous study in sandy soils, found that the dissolved organic matter interfered with the adsorption of antibiotics on the soil particles, causing a higher mobility of the pollutant (Li et al. 2007 ). Regarding the WSIVM, lower topographies presented the highest concentration (2.87 ppm, Table 1 and Fig. 2 ). The fact that WSIVM was mostly detected in the lower areas of the field indicated that the contaminant was leached and transported to those areas from the upper parts of the field, coincidently with the data found for LF_OM (Table 1 ). Although the presence of IVM could represent a threat to the ecosystem as reported by other authors (Mesa et al. 2018 , Mesa et al. 2020 ), the WSIVM should be considered and analysed as a higher risk as it could reach the water courses easily after rainfall and runoff, increasing its bioavailability and further dispersion (Poeplau et al. 2015 , Mesa et al. 2018 , Severini et al. 2018 , Wang et al. 2019 ). What is more, these values are all higher than the lethal concentration of 47 ppb found by Peluso et al. (Cui et al. 2023 ). This result is coincident to the box plot (Fig. 2 A and 2 B) where IVM in the upper areas has less mobility by indication of the lower values for WSIVM. This is also supported by the correlations observed in figure S2, B and S2, C (Supplementary material) where IVM has a positive correlation with LF_OM and WSOM in the lower and midhill areas; and a negative or no correlation in the upper area of the sites, respectively. This indicates the association of IVM to a more mobile and sensitive-to-degradation OM, representing a risk to the environment (Li et al. 2007 ) as mentioned. Results also indicated that WSIVM had a positive correlation with OM in the lower and mid-hill areas; and no correlation in the upper areas S2, D (Supplementary material). This last analysis reinforces the idea of an increased mobility of the IVM through the environment in the mid-hill and lower areas. Overall, regarding the presence and mobility of this antiparasite, the upper sites had a higher content of IVM, whereas the lower areas presented less amount of IVM but higher mobility of the contaminant; representing a threat to the environment. What is more, the positive correlation between WSIVM and OM indicated that a fraction of the total IVM detected in the soil would associate positively with OM but in a labile form, greatly increasing leaching risk (Sheng et al. 2014 , Stefaniuk et al. 2016 ). This behaviour also correlates with the nature of the molecule as ivermectin is hydrophobic as mentioned elsewhere (Verdú et al. 2018 ). Other authors found a tendency of IVM to strongly bind to soil organic matter, with a great variation depending on soil type; indicated by a high organic carbon–water partition coefficient ( K OC ) (Bracco et al. 2023 ). Another study indicated ranges of IVM organic carbon-normalized sorption coefficients from 4.00x10 3 to 2.58x10 4 L.kg − 1 (Krogh et al. 2009 ); emphasizing the influence of other physicochemical parameters and microbial activity (Dionisio y Rath 2016) in IVM dissipation. Nevertheless, knowledge about the basic process of IVM sorption in soils and sediments is limited, whereas the protection of the organic compounds is a complex dynamic equilibrium between all the minerals in the soil. These results highlight the importance of discussing the occurrence of pollutants together with soil features where the complexity of the system causes that some findings might be contradictory. Indeed, a higher amount of vegetation generates a different structure of the soil due to the amount of roots and exudates in the belowground compartments, generating a higher microbial activity. However, degradation or dissipation of these type of pollutants are governed by multiple factors and microbial activity is affected by adsorption of both microorganisms cells (Ahmed y Holmström 2015) and the pollutants onto clays, silt and OM (Al-Khazrajy et al. 2018 ); which might be preventing IVM to dissipate. On the other hand, clays play a protective role of OM, and organic compounds, in anaerobic environments (Lalonde et al. 2012 ); which might be influencing a higher concentration of IVM in these areas. When analysing the %N, results indicated a positive correlation with %TSV (data not shown). However, a study found in bibliography reported that composting manure containing IVM generated a decrease of potentially mineralizable nitrogen, a measure of microbial activity in soil (Konstantinidis et al. 2017 ). Contrarily, a report published by other authors indicated that IVM didn’t affect nitrification processes in soils (Zhao et al. 2023 ). This evidence reinforces the contradictory data found in bibliography, whereas it causes a non-conclusive discussion regarding N in this work. All these observations highlight the multifactorial character in the behaviour of these parameters and the complexity of the studied systems. For a broader insight of the occurrence and mobility of IVM in the environment, main functional groups of soils, through FTIR, spectra were recorded. Figure S3 (Supplementary material) shows the FTIR spectra for all soils studied at each site and topography. The lower areas were the ones with higher amount of aliphatic structures (2940 − 2870 cm − 1 ). The content of aliphatic were in the order lower > midhill > upper. This reinforces the idea of a high mobility of IVM in the lower areas as discussed above. In the case of aliphatics, they can be more easily degraded by soil microbiota (Kornilovych et al. 2020 , Zafar et al. 2021 ), leading to an increase in the mobility of IVM in this topography. Another noticeable characteristic of the spectra is that the upper S site didn’t present a high content of clays (bands at 1095 − 1034 cm − 1 ) as indicated before. This observation is due to the geological origin of the site that is placed in a sand dune (Khan et al. 1995 , Pereyra et al. 2004 ). Meanwhile, in the midhill and lower S sites, there was an increase in the signals associated to polysaccharides and clay functional groups, coincidently also with the mineralogical analysis (supplementary material, table S2). In the case of the site R, it presented a high amount of aromatic functional groups (C = C, C = O at around 1600 cm − 1 ), indicating a lower hydrophobicity of the soil. This could be related to the lower amount of IVM found in the lower R site. Despite the report indicating that there is no risk of the presence of IVM in soils due to its low mobility (Zhao et al. 2023 ), this is the first report that indicates a high mobility of IVM, with a high fraction of WSIVM, depending on the properties of the soils studied; representing a high risk to the environment and highlighting the need of implementing improvements to the grazing activity in wetlands. 4. Conclusions This was the first study where IVM and its soluble fraction were correlated to soil mineralogy, organic matter and topography. Results indicated a higher presence of IVM in the upper topographies opposite to a higher presence of WSIVM in the lower topographies. Indeed, this report indicated the association of IVM to a mobile fraction of the organic matter of the soil which represents a more threatening situation due to the changing tides conditions of wetlands and the proximity of the farms to water courses, increasing the risk of bioavailability of the contaminant. Also, this organic matter fraction was mainly composed by aliphatic compounds, a fraction subjected to microbial activity, increasing even more the risk of mobility. These results help to establishing a background to apply better livestock practices in wetlands, predicting pollutants mobility and their association with carbon stocks. Declarations Funding This work was supported by Ministerio de Ciencia y Tecnología e Innovación, Agencia Nacional de Promoción de la Investigación, el Desarrollo Tecnológico y la Innovación (MSO, PICT 2020-1073), MINCyT-ANPCyT-FONCyT and Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina (CONICET) (MSO: PIP Olivelli Nº0106). JGB doctoral fellowship is supported by CONICET. Competing Interests The authors have no relevant financial or non-financial interests to disclose. Author Contributions All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Jonathan García-Boloquy, Melisa S. Olivelli, Laura M. Calfayan, Olivia Suarez-Cantero, Mariela Fernández, Luciana Montes, Joaquin Salduondo y Juan Pierro-Reboiras. The first draft of the manuscript was written by Melisa S. Olivelli and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript. Data Availability The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request. Acknowledgments The authors acknowledge Universidad Nacional de San Martín (UNSAM), Ministerio de Ciencia y Tecnología e Innovación, Agencia Nacional de Promoción de la Investigación, el Desarrollo Tecnológico y la Innovación (MSO, PICT 2020-1073), MINCyT-ANPCyT-FONCyT and Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina (CONICET) for financial support (MSO: PIP Olivelli Nº0106). JGB acknowledge CONICET for financing his doctoral fellowship. The funding sources had no decision in the submission of the manuscript for its publication. Supplementary information Supplementary material: Total solid volatiles (TSV), total organic matter (OM), total nitrogen (N), total iron content (Fe), light organic matter fraction (%LF_OM), water extractable organic matter (%WSOM), total ivermectin (IVM) and water extractable ivermectin (WSIVM) for each site and each topography. Determination and semi-quantification of levels by means of XRD with the mineral phases documented in the analyzed samples. References Ahmed E, Holmström SJM (2015) Microbe–mineral interactions: The impact of surface attachment on mineral weathering and element selectivity by microorganisms. Chem Geol 403:13–23. https://doi.org/10.1016/j.chemgeo.2015.03.009 Al-Khazrajy OSA, Bergström E, Boxall ABA (2018) Factors affecting the dissipation of pharmaceuticals in freshwater sediments. Environ Toxicol Chem 37(3):829–838. 10.1002/etc.4015 Baldock JA, Skjemstad JO (2000) Role of the soil matrix and minerals in protecting natural organic materials against biological attack. Org Geochem 31(7–8):697–710. 10.1016/S0146-6380( 00)00049 – 8 Bhattacharyya A, Campbell AN, Tfaily MM, Lin Y, Kukkadapu RK, Silver WL, Nico PS, Pett-Ridge J (2018) Redox Fluctuations Control the Coupled Cycling of Iron and Carbon in Tropical Forest Soils. Environ Sci Technol 52(24):14129–14139. 10.1021/acs.est.8b03408 Bracco EB, Marco-Brown JL, Butler M, Candal RJ (2023) Degradation of oxytetracycline and characterization of byproducts generated by Fenton or photo-Fenton like processes after adsorption on natural and iron(III)-modified montmorillonite clays. Environ Nanatechnol Monit Manage 19:100778. 10.1016/j.enmm.2023.100778 Cui S, Qi Y, Zhu Q, Wang C, Sun H (2023) A review of the influence of soil minerals and organic matter on the migration and transformation of sulfonamides. Sci Total Environ 861:160584. https://doi.org/10.1016/j.scitotenv.2022.160584 de Souza RB, Guimarães JR (2022) Effects of Avermectins on the Environment Based on Its Toxicity to Plants and Soil Invertebrates—a. Rev Water Air Soil Pollution 233(7):259. 10.1007/s11270-022-05744-0 Dhillon GS, Rees KCJV (2017) Distribution of soil organic carbon in the light and heavy fractions for six shelterbelt species and their adjacent agricultural fields in Saskatchewan. Can J Soil Sci 97(4):732–744. 10.1139/cjss-2017-0010 Dionisio AC, Rath S (2016) Abamectin in soils: Analytical methods, kinetics, sorption and dissipation. Chemosphere 151:17–29. https://doi.org/10.1016/j.chemosphere.2016.02.058 Dubinsky EA, Silver WL, Firestone MK (2010) Tropical forest soil microbial communities couple iron and carbon biogeochemistry. Ecology 91(9):2604–2612. 10.1890/09-1365.1 Fang L, Chen C, Li S, Ye P, Shi Y, Sharma G, Sarkar B, Shaheen SM, Lee SS, Xiao R, Chen X (2023) A comprehensive and global evaluation of residual antibiotics in agricultural soils: Accumulation, potential ecological risks, and attenuation strategies. Ecotoxicol Environ Saf 262:115175. https://doi.org/10.1016/j.ecoenv.2023.115175 Henderson GS, Black PM, Rodgers KA, Rankin PC (1984) New data on New Zealand vivianite and metavivianite. NZ J Geol Geophys 27(3):367–378. 10.1080/00288306.1984.10422304 Ingerslev F, Halling-Sorensen B (2001) Biodegradability of metronidazole, olaquindox, and tylosin and formation of tylosin degradation products in aerobic soil–manure slurries. Ecotoxicol Environ Saf 48(3):311–320. 10.1006/eesa.2000.2026 Ji J, Zhu Q, Yang X, Wang C (2023) Review of biodegradation of sulfonamide antibiotics influenced by dissolved organic matter and iron oxides. J Environ Chem Eng 11(5):111020. https://doi.org/10.1016/j.jece.2023.111020 Khan SA, Riaz ur R, Khan MA (1995) Adsorption of chromium (III), chromium (VI) and silver (I) on bentonite. Waste Manag 15(4):271–282. 10.1016/0956-053X(95)00025-U Konstantinidis KT, Rosselló-Móra R, Amann R (2017) Uncultivated microbes in need of their own taxonomy. ISME J 11(11):2399–2406. 10.1038/ismej.2017.113 Kornilovych B, Kovalchuk I, Tobilko V, Ubaldini S (2020) Uranium Removal from Groundwater and Wastewater Using Clay-Supported Nanoscale Zero-Valent Iron. Metals 10(11):1421. 10.3390/met10111421 Krogh KA, Jensen GG, Schneider MK, Fenner K, Halling-Sørensen B (2009) Analysis of the dissipation kinetics of ivermectin at different temperatures and in four different soils. Chemosphere 75(8):1097–1104. https://doi.org/10.1016/j.chemosphere.2009.01.015 Krogh KA, Søeborg T, Brodin B, Halling-Sørensen B (2008) Sorption and mobility of ivermectin in different soils. J Environ Qual 37(6):2202–2211. 10.2134/jeq2007.0592 Lalonde K, Mucci A, Ouellet A, Gélinas Y (2012) Preservation of organic matter in sediments promoted by iron. Nature 483(7388):198–200. 10.1038/nature10855 Li Z, Kirk Jones H, Zhang P, Bowman RS (2007) Chromate transport through columns packed with surfactant-modified zeolite/zero valent iron pellets. Chemosphere 68(10):1861–1866. 10.1016/j.chemosphere.2007.03.011 Liebig M, Fernandez ÁA, Blübaum-Gronau E, Boxall A, Brinke M, Carbonell G, Egeler P, Fenner K, Fernandez C, Fink G, Garric J, Halling-Sørensen B, Knacker T, Krogh KA, Küster A, Löffler D, Cots MÁP, Pope L, Prasse C, Römbke J, Rönnefahrt I, Schneider MK, Schweitzer N, Tarazona JV, Ternes TA, Traunspurger W, Wehrhan A, Duis K (2010) Environmental risk assessment of ivermectin: A case study. Integr Environ Assess Manag 6(S1):567–587. https://doi.org/10.1002/ieam.96 Liu Je, Zhang X, Zhou Z (2019) Quantifying effects of root systems of planted and natural vegetation on rill detachment and erodibility of a loessial soil. Soil Tillage Res 195:104420. https://doi.org/10.1016/j.still.2019.104420 Lofrano G, Libralato G, Meric S, Vaiano V, Sacco O, Venditto V, Guida M, Carotenuto M (2020) 1 - Occurrence and potential risks of emerging contaminants in water. Visible Light Active Structured Photocatalysts for the Removal of Emerging Contaminants. O. Sacco and V. Vaiano, Elsevier: 1–25 Marco-Brown JL, Valiente R, Ramos CP, Fernández MA, Candal R (2021) Stable nZVI-based nanocomposites for adsorption and reduction processes: The case of U(VI) removal. Environ Nanatechnol Monit Manage 16:100563. 10.1016/j.enmm.2021.100563 Mesa L, Gutiérrez MF, Montalto L, Perez V, Lifschitz A (2020) Concentration and environmental fate of ivermectin in floodplain wetlands: An ecosystem approach. Sci Total Environ 706:135692. https://doi.org/10.1016/j.scitotenv.2019.135692 Mesa L, Mayora G, Saigo M, Giri F (2015) Nutrient Dynamics in Wetlands of the Middle Paraná River Subjected to Rotational Cattle Management. Wetlands 35(6):1117–1125. 10.1007/s13157-015-0699-2 Mesa LM, Hörler J, Lindt I, Gutiérrez MF, Negro L, Mayora G, Montalto L, Ballent M, Lifschitz A (2018) Effects of the Antiparasitic Drug Moxidectin in Cattle Dung on Zooplankton and Benthic Invertebrates and its Accumulation in a Water-Sediment System. Arch Environ Contam Toxicol 75(2):316–326. 10.1007/s00244-018-0539-5 Mishra A, Mehta A, Basu S (2018) Clay supported TiO2 nanoparticles for photocatalytic degradation of environmental pollutants: A review. J Environ Chem Eng 6(5):6088–6107. 10.1016/j.jece.2018.09.029 Murad E, Cashion J (2004) Mössbauer Spectroscopy of Environmental Materials and Their Industrial Utilization. Springer, New York, NY Navarro M, Alonso LL, Capparelli AL, Marino DJG (2022) Mobilization of ionophore antibiotics and glyphosate after a rainfall simulation on agricultural soils amended with poultry litter. Agric Water Manage 274:107963. https://doi.org/10.1016/j.agwat.2022.107963 Parks DH, Chuvochina M, Rinke C, Mussig AJ, Chaumeil P-A, Hugenholtz P (2021) GTDB: an ongoing census of bacterial and archaeal diversity through a phylogenetically consistent, rank normalized and complete genome-based taxonomy. Nucleic Acids Res 50(D1):D785–D794. 10.1093/nar/gkab776 Peluso J, Chehda AM, Olivelli MS, Ivanic FM, Pérez Coll CS, Gonzalez F, Valenzuela L, Rojas D, Cristos D, Butler M, Candal RJ, Aronzon CM (2023) Metals, pesticides, and emerging contaminants on water bodies from agricultural areas and the effects on a native amphibian. Environ Res 226:115692. https://doi.org/10.1016/j.envres.2023.115692 Pereyra F, Baumann V, Altinier MV, Ferrer J, Pablo T (2004) Génesis de suelos y evolución del paisaje en el delta del río Paraná. Revista de la Asociación Geológica Argentina 59:229–242 Poeplau C, Aronsson H, Myrbeck Å, Kätterer T (2015) Effect of perennial ryegrass cover crop on soil organic carbon stocks in southern Sweden. Geoderma Reg 4:126–133. https://doi.org/10.1016/j.geodrs.2015.01.004 Poggenburg C, Mikutta R, Schippers A, Dohrmann R, Guggenberger G (2018) Impact of natural organic matter coatings on the microbial reduction of iron oxides. Geochim Cosmochim Acta 224. 10.1016/j.gca.2018.01.004 Rancourt D (1998) Recoil-Mössbauer Spectral Analysis Software for Windows. Department of Physics, University of Ottawa, Ontario Ren X, Yan N, Chen S, Yao J, Liu J (2022) Remediation of arsenic-containing ferrihydrite in soil using iron- and sulfate-reducing bacteria: Implications for microbially-assisted clean technology. J Environ Chem Eng 10(6):108876. 10.1016/j.jece.2022.108876 Rice EW, Baird RD, Eaton AD (2017) Standard methods for the examination of water and wastewater. American Water Works Association, Water Environment Federation, Washington, DC, American Public Health Association Schweizer SA, Bucka FB, Graf-Rosenfellner M, Kögel-Knabner I (2019) Soil microaggregate size composition and organic matter distribution as affected by clay content. Geoderma 355:113901. https://doi.org/10.1016/j.geoderma.2019.113901 Severini MDF, Carbone ME, Villagran DM, Marcovecchio JE (2018) Toxic metals in a highly urbanized industry-impacted estuary (Bahia Blanca Estuary, Argentina): spatio-temporal analysis based on GIS. Environ Earth Sci 77(10):393. 10.1007/s12665-018-7565-5 Sheng G, Shao X, Li Y, Li J, Dong H, Cheng W, Gao X, Huang Y (2014) Enhanced Removal of Uranium(VI) by Nanoscale Zerovalent Iron Supported on Na-Bentonite and an Investigation of Mechanism. J Phys Chem A 118(16):2952–2958. 10.1021/jp412404w Sigua GC (2010) Sustainable cow-calf operations and water quality: a review. Agron Sustain Dev 30:631–648 Stefaniuk M, Oleszczuk P, Ok YS (2016) Review on nano zerovalent iron (nZVI): From synthesis to environmental applications. Chem Eng J 287:618–632. 10.1016/j.cej.2015.11.046 Verdú JR, Lobo JM, Sánchez-Piñero F, Gallego B, Numa C, Lumaret J-P, Cortez V, Ortiz AJ, Tonelli M, García-Teba JP, Rey A, Rodríguez A, Durán J (2018) Ivermectin residues disrupt dung beetle diversity, soil properties and ecosystem functioning: An interdisciplinary field study. Sci Total Environ 618:219–228. https://doi.org/10.1016/j.scitotenv.2017.10.331 Vokřál I, Michaela Š, Radka P, Jiří L, Lukáš P, Dominika S, Kateřina L, Barbora S, Lenka S (2019) Ivermectin environmental impact: Excretion profile in sheep and phytotoxic effect in Sinapis alba. Ecotoxicol Environ Saf 169:944–949. https://doi.org/10.1016/j.ecoenv.2018.11.097 Wang M, Cheng W, Wan T, Hu B, Zhu Y, Song X, Sun Y (2019) Mechanistic investigation of U(VI) sequestration by zero-valent iron/activated carbon composites. Chem Eng J 362:99–106. 10.1016/j.cej.2018.12.138 Wang Y, Yu W, Chang Z, Gao C, Yang Y, Zhang B, Wang Y, Xing B (2022) Effects of dissolved organic matter on the adsorption of norfloxacin on a sandy soil (fraction) from the Yellow River of Northern China. Sci Total Environ 848:157495. https://doi.org/10.1016/j.scitotenv.2022.157495 Zafar Z, Fatima R, Kim J-O (2021) Effect of HCl treatment on physico-chemical properties and photocatalytic performance of Fe–TiO2 nanotubes for hexavalent chromium reduction and dye degradation under visible light. Chemosphere 284:131247. 10.1016/j.chemosphere.2021.131247 Zhao X, Teng Z, Wang G, Luo W, Guo Y, Ji X, Hu W, Li M (2023) Anaerobic syntrophic system composed of phosphate solubilizing bacteria and dissimilatory iron reducing bacteria induces cadmium immobilization via secondary mineralization. J Hazard Mater 446:130702. 10.1016/j.jhazmat.2022.130702 Additional Declarations No competing interests reported. Supplementary Files Supplementarymaterial.pdf Cite Share Download PDF Status: Published Journal Publication published 31 Mar, 2025 Read the published version in Environmental Processes → Version 1 posted Editorial decision: Revision requested 29 Nov, 2024 Reviews received at journal 12 Sep, 2024 Reviewers agreed at journal 28 Aug, 2024 Reviews received at journal 27 Aug, 2024 Reviewers agreed at journal 26 Aug, 2024 Reviewers agreed at journal 19 Aug, 2024 Reviewers agreed at journal 19 Aug, 2024 Reviewers invited by journal 17 Aug, 2024 Editor assigned by journal 30 Jul, 2024 Submission checks completed at journal 30 Jul, 2024 First submitted to journal 29 Jul, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Sites are represented as points, with different colours by topography, ordered by the values of the physicochemical variables of the soil\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-4824566/v1/f883065ea0cfd7c2bb1fc197.png"},{"id":63391313,"identity":"2e7d41f7-5a51-4072-a956-448fcb70efbb","added_by":"auto","created_at":"2024-08-27 15:42:31","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":38107,"visible":true,"origin":"","legend":"\u003cp\u003eBox plots of IVM in ppm (a), WSIVM in ppm (b), % LF_OM (c), % OM (d), Hematite (e) and Fe (f) as a function of the topography\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-4824566/v1/2d51fcd988df8fc1a19af5d2.png"},{"id":80082114,"identity":"ee9b61ce-9a06-4478-b58e-4826dd44d48b","added_by":"auto","created_at":"2025-04-07 16:07:23","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":798538,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4824566/v1/4d5e8055-2d30-4acf-afeb-62f986027a63.pdf"},{"id":63391314,"identity":"885a8c59-7935-41ea-a5e7-7aed41b660dc","added_by":"auto","created_at":"2024-08-27 15:42:31","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":876038,"visible":true,"origin":"","legend":"","description":"","filename":"Supplementarymaterial.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4824566/v1/b8404e4e3d8a8c63849f720a.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Ivermectin mobility in Delta del Paraná wetlands: influence of topography and soil geochemical features","fulltext":[{"header":"Article Highlights","content":"\u003cp\u003e- High concentrations of ivermectin found in Delta del Paran\u0026aacute; wetland\u0026acute;s soils\u003c/p\u003e\n\u003cp\u003e- 23.50 ppm of ivermectin in upper zones and around 15 ppm in lower and midhill zones\u003c/p\u003e\n\u003cp\u003e- 2.78 ppm of soluble ivermectin found in lower zones increasing risk of ivermectin entering to water courses\u003c/p\u003e"},{"header":"1. Introduction","content":"\u003cp\u003eOver the past few decades wetlands have suffered of a significant loss across the globe being degraded by climate change and human activities. The grazing activities in these ecosystems have increased significantly due to the expansion of the agricultural frontier, so an increase in the number of animals and engineering works for water management (channelling and dykes) were observed. Although cattle with open access to riparian zones of floodplain lakes can contribute to nutrients dynamics in soils (by manure input or sediment movement by cattle activity) (Mesa et al. \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2015\u003c/span\u003e), the effect of this activity in subtropical floodplain wetlands is scarcely known (Sigua \u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e2010\u003c/span\u003e). Among the negative impacts, alteration of nutrients dynamics and the contamination of soils and waters with veterinary products were mentioned (Wang et al. \u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e2019\u003c/span\u003e, Mesa et al. \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2020\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn Delta del Paran\u0026aacute; wetlands in Argentina, grazing constitutes one of the traditional productive activities. Previous studies in the middle Delta found accumulation of the antiparasite ivermectin (IVM) in aquatic assemblages, soil, sediments, plants and manure (Mesa et al. \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2020\u003c/span\u003e); as 80 to 98% of the drug is estimated to leave the animal, without being metabolized, in faeces (Ren et al. \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). The risk of the presence of IVM in the environment relies on its high phytotoxic effect (Vokř\u0026aacute;l et al. \u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e2019\u003c/span\u003e) and also causes high toxicity in invertebrates (Verd\u0026uacute; et al. \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e2018\u003c/span\u003e), even for those that inhabit sediments (Lofrano et al. \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2020\u003c/span\u003e); being able to disrupt the balance of aquatic populations and harm non-target species (Mesa et al. \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). The persistence of IVM can lead to long-term accumulation and affecting the aquatic biodiversity (Verd\u0026uacute; et al. \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). However, reports of IVM in the environment are scarce. In Argentina, concentrations near 1 ppb were previously reported in water courses near agricultural areas (Mesa et al. \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2020\u003c/span\u003e, Peluso et al. \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). Additionally, a previous study indicated alterations in the biomarkers of oxidative stress and neurotoxicity when exposing \u003cem\u003eRhinella arenarum\u003c/em\u003e larvae to 1.25 ppb of IVM and a lethal concentration for those amphibians of 47 ppb (Cui et al. \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2023\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe mechanisms through which these contaminants reach different environmental compartments and accumulate, i.e. in soils, are related to their mobility, whereas this will depend on their solubility, the type of soil, oxygenation conditions, percentage and stability of the organic matter present (Ingerslev y Halling-Sorensen 2001, Krogh et al. \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2009\u003c/span\u003e) and the hydrological regime. In fact, dissipation half-lives (DT50) in soil can be rather variable depending on soil type, sorption capacity, temperature, and oxygen availability, ranging from 16 to 1520 days. IVM can be also very persistent in mixtures of soil and manure or faeces (7-217 days) (Zhao et al. \u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e2023\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eHowever, the degree to which abiotic factors influence veterinary drugs accumulation in productive soils on a large scale remains poorly understood (Mishra et al. \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). One of the most important abiotic factors governing organic pollutants persistence is organic matter. There are many reports indicating that pharmaceutically active compounds were protected against degradation or mobilization through adsorption on soil organic matter (Henderson et al. \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e1984\u003c/span\u003e, Baldock y Skjemstad 2000, Ji et al. \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). However this association will be more or less stable depending on the chemical nature of the soil organic matter and the soil mineral matrix. Iron oxides, clays and multivalent cations offer mechanisms of protection to organic matter, additionally to the chemically intrinsic recalcitrance of the different organic matter structures such as \u003cem\u003eO\u003c/em\u003e-Alkyl C, Alkyl C, phenolic or aromatic (Baldock y Skjemstad 2000). Additionally to these complex protection mechanisms, soil redox conditions also influence the exposure of organic matter to biological oxidation. Due to the wetlands changing hydrology regimes, important redox processes take place playing a fundamental role in the cycling of nutrients (OC, N, P) (Dubinsky et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2010\u003c/span\u003e, Mesa et al. \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2015\u003c/span\u003e) or elements such as Fe or Al (Bhattacharyya et al. \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Particularly, iron mineral particles have a preservative effect on organic matter through direct adsorption on their surfaces in oxidic conditions, whereas in anoxic micro-environments, OM becomes susceptible to degradation by iron reducing bacteria, resulting in the solubilisation of both low molecular weight OM and Fe(II). Contrarily, clay minerals protect adsorbed organic matter while conditions are anaerobic as their surface cannot be reactive to microbial oxidation or reduction. Thus, the stability and/or mobility of the veterinary drugs that enter a wetland ecosystem will be subjected to the dynamics of these organo-mineral associations. Particularly, it has been reported that IVM can be associated to OM and can be accumulated in soils (Liebig et al. \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2010\u003c/span\u003e) as well as it can present a high dissipation coefficient in aerobic conditions (Krogh et al. \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2008\u003c/span\u003e). This evidence reinforces the need for a comprehensive study of organic matter, soil components, and redox conditions in the study area in order to determine the bioavailability and possible environmental risk of Ivermectin. Therefore, the objective of this work was to analyse the presence and mobility of Ivermectin in relation to the physicochemical characteristics of different types of soils and topography from fields of the lower non-insular Delta del Paran\u0026aacute;. This study will help to understand the occurrence and fate of the IVM, in wetlands with grazing activities, accordingly to the physicochemical characterization of soils and will help to evaluate the risk of using IVM in these type of ecosystems.\u003c/p\u003e"},{"header":"2. Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1. Sampling sites\u003c/h2\u003e \u003cp\u003eThree cattle fields located in the area of Delta del Parana wetlands were studied (Figure \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e, A, Supplementary material). Fields were indicated as S, C and R. The establishments were located in the area of ​​Ceibas, Villa Paranacito and Ibiquy (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Soil samples were taken from each field in the different topographies: upper, lower, and midhill areas; at 0\u0026ndash;15 cm depths using a hand auger. The upper, midhill or lower areas of the fields correspond to the topography of the wetland; being the dry area, the hydrological-regime dependent area and the flooded area, respectively (Figure \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e, B, Supplementary material). Four samples were taken at each site and topography, and mixed to have an integrated sample. Samples were air-dried at room temperature, crushed, and passed through a 2 mm sieve to separate and discard the coarse stone fragments. These soil samples were used for the laboratory analysis, including density fractionation.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e2.2. Characterization of soils\u003c/h2\u003e \u003cdiv id=\"Sec5\" class=\"Section3\"\u003e \u003ch2\u003e2.2.1. Iron Content\u003c/h2\u003e \u003cp\u003eIron (Fe) environments were studied by M\u0026ouml;ssbauer spectroscopy. This technique was employed to identify Fe\u003csup\u003e3+\u003c/sup\u003e and Fe\u003csup\u003e2+\u003c/sup\u003e sites in soil samples. The \u003csup\u003e57\u003c/sup\u003eFe M\u0026ouml;ssbauer spectra were recorded at room temperature using a transmission geometry spectrometer with constant acceleration. The spectrometer utilized a \u003csup\u003e57\u003c/sup\u003eCoRh source with a nominal activity of 50 mCi. The velocity calibration was performed using the \u003csup\u003e57\u003c/sup\u003eFe M\u0026ouml;ssbauer spectrum of a 12 \u0026micro;m-thick α-Fe foil, which was measured under the same conditions as the samples. The isomer shifts (δ) were then referenced to this standard. All the spectra were analyzed using a program that considers the static distributions of quadrupole splitting and hyperfine magnetic fields (de Souza y Guimar\u0026atilde;es 2022). The total Fe concentration was calculated using the fitted spectrum and the method proposed by Montes (Liebig et al. \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2010\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section3\"\u003e \u003ch2\u003e2.2.2. Mineralogy\u003c/h2\u003e \u003cp\u003eFor mineralogical analysis by X-ray diffraction (XRD), the tuff samples were first air-dried and then stove-dried at 60\u0026deg;C. The determination of the mineral phases was made on random powders using a Phillips-PW3710 (Ni-filtered CuKα, 35 Kv, 40 Ma, without secondary monochromator). Samples were analyzed from 3\u0026deg; to 70\u0026deg;2θ, with a step width of 0.04\u0026deg; for 2 s, giving a step scan of 1\u0026deg;2θ/min. The determination of the clay minerals was performed on the fraction less than 2 \u0026micro;m on air dried oriented aggregates (2\u0026deg;2θ \u0026ndash; 32\u0026deg;2θ), ethylen glycol solvated (2\u0026deg;2θ\u0026thinsp;\u0026minus;\u0026thinsp;30\u0026deg;2θ) and calcined at 550\u0026deg;C for 2 h (3\u0026deg;2θ\u0026thinsp;\u0026minus;\u0026thinsp;15\u0026deg;2θ) using a Bruker D2 Phaser. For the qualitative determination of the mineral phases the programs X'Pert Higscore Plus, for whole rock, and OriginPro 8, for the fraction less than 2 \u0026micro;m were used. The semi-quantitative determination of the mineral phases: Quartz (Qz), Alkali feldspar (Afs), Plagioclase (Pl), Smectite (Sme), Illite (I), Kaolinite (Kln) and Chlorite (Chl), was performed on the whole rock diagrams using the SiroquantTM program.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section3\"\u003e \u003ch2\u003e2.2.3. Relevant soil functional groups\u003c/h2\u003e \u003cp\u003eThe most relevant functional groups in soils were analyzed using Fourier-transform infrared transmission spectroscopy (FTIR). The measurements were conducted using a Thermo Scientific Nicolet FT-IR 6700 instrument with a resolution of 4 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. KBr was used as a background. First, the samples were dried at 60 \u0026ordm;C, and KBr was dried at 100 \u0026ordm;C for 24 hours. The samples, all having the same mass, were diluted 1:100 using the dried KBr. The mixture was grounded, placed in a pellet stainless steel holder, and pressed with a hydraulic press at 10 bars. Each FTIR spectrum was based on 128 scans in the range of 4000\u0026thinsp;\u0026minus;\u0026thinsp;400 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section3\"\u003e \u003ch2\u003e2.2.4. Organic matter\u003c/h2\u003e \u003cp\u003eTotal volatile solids (TVS) was performed by calcination of the dried samples for 3 hours at 550\u0026ordm;C. Organic matter (OM) was determined by the Walkley and Black method (Navarro et al. \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e2022\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eTo predict C mineralization and to evaluate the leaching of dissolved organic matter (WSOM), the following procedure was performed (Liu et al. 2019): 20g of soil simple was stirred with 100 ml of water at 200 rpm during 1 hour, at ambient temperature (Poeplau et al. \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2015\u003c/span\u003e). The sample was centrifuged and the supernatant was separated in a 10ml and a 90 ml aliquots. Total organic carbon was measured with a Total Organic Carbon analyser in the 10ml aliquot. The rest of the supernatant was used to assess the presence and content of IVM (referred as WSIVM).\u003c/p\u003e \u003cp\u003eThe procedure for the Light fraction of the organic matter (LF_OM) was adapted from Kooch et al. (Liu et al. 2019) and Dhillon et. Al. (Severini et al. \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e2018\u003c/span\u003e): 10g soil was agitated in 25ml of NaI (1.8g/cm3) for 60 min at 200 rpm. Then, the sample was centrifuged 15 min at 3600 rpm and the supernatant was filtered through a glass fibre membrane (0.7 um pore diameter). Sample on the filter was washed with 100 ml of distilled water followed by 25 ml of a CaCl 0.01M solution. Membranes were dried at 45\u0026ordm;C for 24 hours and the LF_OM fraction was determined by weight. The percentage value of LF_OM indicates the amount of labile organic matter as the fraction of the total amount of organic matter.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003e2.3. Ivermectin Analysis\u003c/h2\u003e \u003cp\u003eThe method for the extraction of IVM and quantification from experimental samples and quantification of IVM by HPLC analysis was performed as in (Peluso et al. \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e2023\u003c/span\u003e) by duplicate. Briefly, samples were weighed and homogenized with the internal standard abamectin, PESTANAL\u0026reg; and acetonitrile (1g/ml). The preparation was incubated in agitation for 15 min and then sonicated for 20 minutes at ambient temperature. The solvent-sample mixture was centrifuged at 3500 \u003cem\u003eg\u003c/em\u003e for 15 min. For the quantification of the IVM in the water soluble fraction of the soil (WSIVM), a portion of the aqueous extract from the organic matter fractionation was used. The supernatant or the aliquot of the aqueous extract described in the previous section was filtered through a solid-phase extraction (C18 SPE) cartridge and eluted with 100% acetonitrile (HPLC-MS quality). IVM concentrations were determined by HPLC-MS using a Thermo Scientific Ultimate 3000 equipped with an autosampler. HPLC analysis was undertaken using a reverse phase C18 column (Hypersil Gold, USA, 1.9 \u0026micro;m, 2.1 mm \u0026times; 50 mm) and a 5 mM NH\u003csub\u003e4\u003c/sub\u003eAcO with 0.05% Acetic acid/Acetonitrile (25/75) mobile phase at a flow rate of 0.2 ml/min at 30\u0026deg;C. IVM was detected with a mass detector (ThermoScientific LTQ XL). Calibration curves were constructed in the range of 10 to 1000 ug L\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. The correlation coefficients of calibration curves were \u0026gt;\u0026thinsp;0.99.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003e2.4. Data Analysis\u003c/h2\u003e \u003cp\u003eTo resume the physicochemical characteristics of the soils and the amount of IVM, of the different sites and topographies, a Principal Component Analysis (PCA) was made on the correlation matrix (Dhillon y Rees 2017). The sites where described by means of the inorganic (Fe, Sme, I, Kln, Chl), organic features (OM, WSOM, LF_OM, TSV, N); and the IVM and WSIVM, differentiating the three topographies. As for this analysis we need a complete data matrix without missing values and all quantitative data, in the case of non-detection of some compounds, we assigned a zero value and in the case of detection but non-quantification, we assigned the middle value between the non-detection and detection limits (table \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eTo study the correlation between the accumulation of IVM and its mobility (WSIVM) with some interesting physicochemical variables, Pearson\u0026rsquo;s correlation tests were made. For the mid-hill of the site C there was an error in the quantification of IVM and WSIVM, so this case was not taken into account for the analysis. All the analysis were made with R software (Wang et al. \u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). For the PCA, the \u0026ldquo;vegan\u0026rdquo; package was used (Murad y Cashion 2004).\u003c/p\u003e \u003c/div\u003e"},{"header":"3. Results and discussion","content":"\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003e3.1. Geochemical features\u003c/h2\u003e \u003cp\u003eIn this study, we examined various sites (S, R, and C) across the different topographies to assess soil physicochemical parameters and IVM. Table \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e (Supplementary material) shows the results obtained for inorganic and organic characterization of the soils of the different topographies at each studied site. With the data obtained from table \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e, PCA plots were performed in an attempt to order the sites according to the soil features found in each one. Results are depicted in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eWith the first two axis of the PCA, 63.43% of the total variability of the data could be explained (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eWhen analysing the behaviour of variables with the topography it is noteworthy to mention that upper sites (black dots, Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e) are mainly ordered on the first principal axis. This axis is associated to a gradient of contents of IVM, clays (Sme, Kln), iron compunds (Fe, Hematite),WSOM and N. Negative values on this axis represent a high content of IVM, clays and iron; and less content of N. Meanwhile, midhill (red dots) and lower sites (green dots) are mainly ordered on the second principal axis. This axis is associated to a gradient of contents of OM, WSOM, WSIVM, LF_OM, TSV and N. Positive values on this axis represent a high content of LF_OM, WSOM, TSV and N. Negative values on this axis represent high content OM and WSIVM.\u003c/p\u003e \u003cp\u003eThe IVM on soil was more related to upper sites; whereas WSIM was more related to the midhill and lower sites (sites in a more frequent contact with water, according to the hydrological regime).\u003c/p\u003e \u003cp\u003eRegarding the presence and amount of Chl and I clays, they presented low amounts in all sites. As expected, these two clays behaved independently to the rest of the variables.\u003c/p\u003e \u003cp\u003eAs a summary, results indicated that IVM was related to the upper sites and could be influenced by mineralogical features of soils; whereas WSIVM was more related to midhill and lower sites and could be influenced by the different fractions of the organic matter of the soil.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003e3.2. Accumulation and mobility of IVM in relation to soil characteristics\u003c/h2\u003e \u003cp\u003eAs described by the PCA results, to discuss the occurrence and mobility of IVM among topographies, it is important to analyse it in terms of the organic matter variables: OM, LF_OM and WSOM; and the diverse physicochemical parameters, together with the IVM and the WSIVM contents. Data was resumed by topography in Table \u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003eIVM and WSIVM were found in all sites (Table \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e, supplementary material); however its distribution was not homogenous among sites as will be discussed further. IVM was slightly higher in the upper sites with a value of 23.50\u0026thinsp;\u0026plusmn;\u0026thinsp;13.86 ppm; and WSIVM was highest in the lower topography presenting a value of 2.87\u0026thinsp;\u0026plusmn;\u0026thinsp;0.41 ppm (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e); coincidently with the PCA results.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMean and standard error for ivermectin and soil\u0026rsquo;s physicochemical characteristics for each topographic type. IVM, Ivermectin; WSIVM, Water soluble Ivermectin; OM, Organic matter; LF_OM, Light fraction_Organic matter; Fe, Total Iron; TSV, Total Solid Volatiles; N, Nitrogen\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTopography\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLower\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMidhill\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eUpper\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eIVM (ppm)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e16.06\u0026thinsp;\u0026plusmn;\u0026thinsp;8.91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e14.25\u0026thinsp;\u0026plusmn;\u0026thinsp;9.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e23.50\u0026thinsp;\u0026plusmn;\u0026thinsp;13.86\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eWSIVM (ppm)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.87\u0026thinsp;\u0026plusmn;\u0026thinsp;0.41\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e0.45\u0026thinsp;\u0026plusmn;\u0026thinsp;0.45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e1.00\u0026thinsp;\u0026plusmn;\u0026thinsp;0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eOM (%)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7.37\u0026thinsp;\u0026plusmn;\u0026thinsp;2.97\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e2.27\u0026thinsp;\u0026plusmn;\u0026thinsp;0.74\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e6.03\u0026thinsp;\u0026plusmn;\u0026thinsp;0.92\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eLF_OM (%)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.77\u0026thinsp;\u0026plusmn;\u0026thinsp;0.61\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e2.93\u0026thinsp;\u0026plusmn;\u0026thinsp;1.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e3.70\u0026thinsp;\u0026plusmn;\u0026thinsp;1.42\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eWSOM (ppm)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21.67\u0026thinsp;\u0026plusmn;\u0026thinsp;11.26\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e14.02\u0026thinsp;\u0026plusmn;\u0026thinsp;13.97\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e21.01\u0026thinsp;\u0026plusmn;\u0026thinsp;13.05\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eFe (g/kg)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e25.00\u0026thinsp;\u0026plusmn;\u0026thinsp;5.20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e14.00\u0026thinsp;\u0026plusmn;\u0026thinsp;5.57\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e27.67\u0026thinsp;\u0026plusmn;\u0026thinsp;17.15\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eHematite\u0026nbsp;(g/kg)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e0.35\u0026thinsp;\u0026plusmn;\u0026thinsp;0.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e1.51\u0026thinsp;\u0026plusmn;\u0026thinsp;0.76\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eTSV (%)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e15.10\u0026thinsp;\u0026plusmn;\u0026thinsp;7.97\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e14.23\u0026thinsp;\u0026plusmn;\u0026thinsp;5.77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e10.83\u0026thinsp;\u0026plusmn;\u0026thinsp;5.27\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eN (%)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.73\u0026thinsp;\u0026plusmn;\u0026thinsp;0.56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e0.36\u0026thinsp;\u0026plusmn;\u0026thinsp;0.24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e0.11\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eAll the studied samples revealed the presence of two Fe\u003csup\u003e3+\u003c/sup\u003e sites, one Fe\u003csup\u003e2+\u003c/sup\u003e site and one site of paramagnetic relaxation. These signals could be associated to common clays present in soils, including Sme, I and Kln as major clays minerals (Liebig et al. \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2010\u003c/span\u003e) as also showed by XRD studies (table S2, supporting information). The paramagnetic relaxation site agrees with the relatively low Fe concentration in the studied soils and could be related to Kln presence (Fang et al. \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2023\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eHematite was found predominantly in upper sites with values ranging from 0.35 to 1.51 g/kg, and total Fe concentrations varied significantly across all sites, ranging from 2 to 59 g/kg (Table \u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The lower and upper sites had a similar amount of Fe content, regardless that hematite was not found in lower sites. This could be impacted by the presence of iron reducing bacteria in the lower and anoxic areas, which degrade organic matter while reducing and solubilizing Fe from iron oxides (Rancourt \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e1998\u003c/span\u003e, Poggenburg et al. \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). This caused that the lower areas presented the lowest values for LF_OM (1.77%) compared to the mid-hill and upper topographies (2.93 and 3.70%, respectively); as anoxigenic conditions were favoured by the presence of water (Lalonde et al. \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). Despite the high content of iron, and the presence of iron reducers in the lower topographies, total OM presented the highest value in this area (7.37%) as Sme are also present in the lower sites and they still play an important role in the protective dynamic equilibrium of soil organic matter (Schweizer et al. \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e2019\u003c/span\u003e) regardless of the iron concentration (Baldock y Skjemstad 2000).\u003c/p\u003e \u003cp\u003eRegarding the amount and correlation between IVM and OM, in the lower areas there was a negative trend but not significant association (r= -0.7678505; p-valor\u0026thinsp;=\u0026thinsp;0.4427; figure S2, A, Supplementary material). Negative associations have been reported for certain veterinary drugs such as antibiotics in soils (Mishra et al. \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). On the other hand, the upper topography presented a positive correlation for IVM vs OM (r\u0026thinsp;=\u0026thinsp;0.9999436; p \u0026ndash; valor\u0026thinsp;=\u0026thinsp;0.006764), which could be indicating a stronger association between OM and IVM for upper areas and lighter associations between these variables in lower areas (figure S2, A, Supplementary material); as also observed in the PCA results. Results indicated that the presence of IVM in the upper sites is influenced mainly by Fe, clay minerals and WSOM. This could be related in part to the drier conditions of this sampling point compared to the lower sites, favouring the oxygenation of the soil and thus generating a protection of the IVM by the Fe oxides content (Lalonde et al. \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). The IVM found in the lower sites can be explained by the presence of clays and OM (Parks et al. \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). This last observation is coincident with a report where the persistence of IVM under anaerobic conditions was observed (Krogh et al. \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2009\u003c/span\u003e, Rice et al. \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). Also, it was reported that pharmaceuticals with similar structures may also behave differently and that the factors governing their mobility in sediments were unclear (Al-Khazrajy et al. \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2018\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIt is noteworthy that the amount of IVM in the lower areas is still considerable compared to the other topographies (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e) as the cattle frequently enters the water course for drinking or refreshing and there is a leaching of IVM from the higher areas of the field; causing IVM to accumulate in the lower areas of the wetlands. The tendency of fewer presence of IVM in the mid-hill and lower sites, could be due to the low values of LF_OM in those sites that generates a higher degradation or mobility of IVM through the environment, as previously reported for other similar pollutants (Marco-Brown et al. \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Additionally, the upper sites has higher amounts of LF_OM compared to the values found for the other sites; which could be contributing to the mobility of pollutants through leaching, thus supporting our statement. A previous study in sandy soils, found that the dissolved organic matter interfered with the adsorption of antibiotics on the soil particles, causing a higher mobility of the pollutant (Li et al. \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2007\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eRegarding the WSIVM, lower topographies presented the highest concentration (2.87 ppm, Table \u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e and Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The fact that WSIVM was mostly detected in the lower areas of the field indicated that the contaminant was leached and transported to those areas from the upper parts of the field, coincidently with the data found for LF_OM (Table \u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Although the presence of IVM could represent a threat to the ecosystem as reported by other authors (Mesa et al. \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2018\u003c/span\u003e, Mesa et al. \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2020\u003c/span\u003e), the WSIVM should be considered and analysed as a higher risk as it could reach the water courses easily after rainfall and runoff, increasing its bioavailability and further dispersion (Poeplau et al. \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2015\u003c/span\u003e, Mesa et al. \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2018\u003c/span\u003e, Severini et al. \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e2018\u003c/span\u003e, Wang et al. \u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). What is more, these values are all higher than the lethal concentration of 47 ppb found by Peluso et al. (Cui et al. \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2023\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThis result is coincident to the box plot (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eA and \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eB) where IVM in the upper areas has less mobility by indication of the lower values for WSIVM. This is also supported by the correlations observed in figure S2, B and S2, C (Supplementary material) where IVM has a positive correlation with LF_OM and WSOM in the lower and midhill areas; and a negative or no correlation in the upper area of the sites, respectively. This indicates the association of IVM to a more mobile and sensitive-to-degradation OM, representing a risk to the environment (Li et al. \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2007\u003c/span\u003e) as mentioned. Results also indicated that WSIVM had a positive correlation with OM in the lower and mid-hill areas; and no correlation in the upper areas S2, D (Supplementary material). This last analysis reinforces the idea of an increased mobility of the IVM through the environment in the mid-hill and lower areas.\u003c/p\u003e \u003cp\u003eOverall, regarding the presence and mobility of this antiparasite, the upper sites had a higher content of IVM, whereas the lower areas presented less amount of IVM but higher mobility of the contaminant; representing a threat to the environment. What is more, the positive correlation between WSIVM and OM indicated that a fraction of the total IVM detected in the soil would associate positively with OM but in a labile form, greatly increasing leaching risk (Sheng et al. \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e2014\u003c/span\u003e, Stefaniuk et al. \u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). This behaviour also correlates with the nature of the molecule as ivermectin is hydrophobic as mentioned elsewhere (Verd\u0026uacute; et al. \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Other authors found a tendency of IVM to strongly bind to soil organic matter, with a great variation depending on soil type; indicated by a high organic carbon\u0026ndash;water partition coefficient (\u003cem\u003eK\u003c/em\u003e\u003csub\u003eOC\u003c/sub\u003e) (Bracco et al. \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). Another study indicated ranges of IVM organic carbon-normalized sorption coefficients from 4.00x10\u003csup\u003e3\u003c/sup\u003e to 2.58x10\u003csup\u003e4\u003c/sup\u003e L.kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e (Krogh et al. \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2009\u003c/span\u003e); emphasizing the influence of other physicochemical parameters and microbial activity (Dionisio y Rath 2016) in IVM dissipation. Nevertheless, knowledge about the basic process of IVM sorption in soils and sediments is limited, whereas the protection of the organic compounds is a complex dynamic equilibrium between all the minerals in the soil. These results highlight the importance of discussing the occurrence of pollutants together with soil features where the complexity of the system causes that some findings might be contradictory.\u003c/p\u003e \u003cp\u003eIndeed, a higher amount of vegetation generates a different structure of the soil due to the amount of roots and exudates in the belowground compartments, generating a higher microbial activity. However, degradation or dissipation of these type of pollutants are governed by multiple factors and microbial activity is affected by adsorption of both microorganisms cells (Ahmed y Holmstr\u0026ouml;m 2015) and the pollutants onto clays, silt and OM (Al-Khazrajy et al. \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2018\u003c/span\u003e); which might be preventing IVM to dissipate. On the other hand, clays play a protective role of OM, and organic compounds, in anaerobic environments (Lalonde et al. \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2012\u003c/span\u003e); which might be influencing a higher concentration of IVM in these areas.\u003c/p\u003e \u003cp\u003eWhen analysing the %N, results indicated a positive correlation with %TSV (data not shown). However, a study found in bibliography reported that composting manure containing IVM generated a decrease of potentially mineralizable nitrogen, a measure of microbial activity in soil (Konstantinidis et al. \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). Contrarily, a report published by other authors indicated that IVM didn\u0026rsquo;t affect nitrification processes in soils (Zhao et al. \u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). This evidence reinforces the contradictory data found in bibliography, whereas it causes a non-conclusive discussion regarding N in this work.\u003c/p\u003e \u003cp\u003eAll these observations highlight the multifactorial character in the behaviour of these parameters and the complexity of the studied systems.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFor a broader insight of the occurrence and mobility of IVM in the environment, main functional groups of soils, through FTIR, spectra were recorded. Figure S3 (Supplementary material) shows the FTIR spectra for all soils studied at each site and topography. The lower areas were the ones with higher amount of aliphatic structures (2940\u0026thinsp;\u0026minus;\u0026thinsp;2870 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e). The content of aliphatic were in the order lower\u0026thinsp;\u0026gt;\u0026thinsp;midhill\u0026thinsp;\u0026gt;\u0026thinsp;upper. This reinforces the idea of a high mobility of IVM in the lower areas as discussed above. In the case of aliphatics, they can be more easily degraded by soil microbiota (Kornilovych et al. \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2020\u003c/span\u003e, Zafar et al. \u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e2021\u003c/span\u003e), leading to an increase in the mobility of IVM in this topography.\u003c/p\u003e \u003cp\u003eAnother noticeable characteristic of the spectra is that the upper S site didn\u0026rsquo;t present a high content of clays (bands at 1095\u0026thinsp;\u0026minus;\u0026thinsp;1034 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) as indicated before. This observation is due to the geological origin of the site that is placed in a sand dune (Khan et al. \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e1995\u003c/span\u003e, Pereyra et al. \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e2004\u003c/span\u003e). Meanwhile, in the midhill and lower S sites, there was an increase in the signals associated to polysaccharides and clay functional groups, coincidently also with the mineralogical analysis (supplementary material, table S2). In the case of the site R, it presented a high amount of aromatic functional groups (C\u0026thinsp;=\u0026thinsp;C, C\u0026thinsp;=\u0026thinsp;O at around 1600 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), indicating a lower hydrophobicity of the soil. This could be related to the lower amount of IVM found in the lower R site.\u003c/p\u003e \u003cp\u003eDespite the report indicating that there is no risk of the presence of IVM in soils due to its low mobility (Zhao et al. \u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e2023\u003c/span\u003e), this is the first report that indicates a high mobility of IVM, with a high fraction of WSIVM, depending on the properties of the soils studied; representing a high risk to the environment and highlighting the need of implementing improvements to the grazing activity in wetlands.\u003c/p\u003e \u003c/div\u003e"},{"header":"4. Conclusions","content":"\u003cp\u003eThis was the first study where IVM and its soluble fraction were correlated to soil mineralogy, organic matter and topography. Results indicated a higher presence of IVM in the upper topographies opposite to a higher presence of WSIVM in the lower topographies. Indeed, this report indicated the association of IVM to a mobile fraction of the organic matter of the soil which represents a more threatening situation due to the changing tides conditions of wetlands and the proximity of the farms to water courses, increasing the risk of bioavailability of the contaminant. Also, this organic matter fraction was mainly composed by aliphatic compounds, a fraction subjected to microbial activity, increasing even more the risk of mobility. These results help to establishing a background to apply better livestock practices in wetlands, predicting pollutants mobility and their association with carbon stocks.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by Ministerio de Ciencia y Tecnolog\u0026iacute;a e Innovaci\u0026oacute;n, Agencia Nacional de Promoci\u0026oacute;n de la Investigaci\u0026oacute;n, el Desarrollo Tecnol\u0026oacute;gico y la Innovaci\u0026oacute;n (MSO, PICT 2020-1073), MINCyT-ANPCyT-FONCyT and Consejo Nacional de Investigaciones Cient\u0026iacute;ficas y T\u0026eacute;cnicas de la Rep\u0026uacute;blica Argentina (CONICET) (MSO: PIP Olivelli N\u0026ordm;0106).\u0026nbsp;JGB doctoral fellowship is supported by CONICET.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors have no relevant financial or non-financial interests to disclose.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll authors contributed to the study conception and design.\u0026nbsp;Material preparation, data collection and analysis were performed by Jonathan Garc\u0026iacute;a-Boloquy, Melisa S. Olivelli, Laura M. Calfayan, Olivia Suarez-Cantero, Mariela Fern\u0026aacute;ndez, Luciana Montes, Joaquin Salduondo y Juan Pierro-Reboiras.\u0026nbsp;The first draft of the manuscript was written by Melisa S. Olivelli and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors acknowledge Universidad Nacional de San Mart\u0026iacute;n (UNSAM), Ministerio de Ciencia y Tecnolog\u0026iacute;a e Innovaci\u0026oacute;n, Agencia Nacional de Promoci\u0026oacute;n de la Investigaci\u0026oacute;n, el Desarrollo Tecnol\u0026oacute;gico y la Innovaci\u0026oacute;n (MSO, PICT 2020-1073), MINCyT-ANPCyT-FONCyT and Consejo Nacional de Investigaciones Cient\u0026iacute;ficas y T\u0026eacute;cnicas de la Rep\u0026uacute;blica Argentina (CONICET) for financial support (MSO: PIP Olivelli N\u0026ordm;0106). JGB acknowledge CONICET for financing his doctoral fellowship. The funding sources had no decision in the submission of the manuscript for its publication.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSupplementary information\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSupplementary material: Total solid volatiles (TSV), total organic matter (OM), total nitrogen (N), total iron content (Fe), light organic matter fraction (%LF_OM), water extractable organic matter (%WSOM), total ivermectin (IVM) and water extractable ivermectin (WSIVM) for each site and each topography. Determination and semi-quantification of levels by means of XRD with the mineral phases documented in the analyzed samples.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAhmed E, Holmstr\u0026ouml;m SJM (2015) Microbe\u0026ndash;mineral interactions: The impact of surface attachment on mineral weathering and element selectivity by microorganisms. Chem Geol 403:13\u0026ndash;23. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.chemgeo.2015.03.009\u003c/span\u003e\u003cspan address=\"10.1016/j.chemgeo.2015.03.009\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAl-Khazrajy OSA, Bergstr\u0026ouml;m E, Boxall ABA (2018) Factors affecting the dissipation of pharmaceuticals in freshwater sediments. Environ Toxicol Chem 37(3):829\u0026ndash;838. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1002/etc.4015\u003c/span\u003e\u003cspan address=\"10.1002/etc.4015\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBaldock JA, Skjemstad JO (2000) Role of the soil matrix and minerals in protecting natural organic materials against biological attack. Org Geochem 31(7\u0026ndash;8):697\u0026ndash;710. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/S0146-6380(\u003c/span\u003e\u003cspan address=\"10.1016/S0146-6380(\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e00)00049\u0026thinsp;\u0026ndash;\u0026thinsp;8\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBhattacharyya A, Campbell AN, Tfaily MM, Lin Y, Kukkadapu RK, Silver WL, Nico PS, Pett-Ridge J (2018) Redox Fluctuations Control the Coupled Cycling of Iron and Carbon in Tropical Forest Soils. Environ Sci Technol 52(24):14129\u0026ndash;14139. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/acs.est.8b03408\u003c/span\u003e\u003cspan address=\"10.1021/acs.est.8b03408\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBracco EB, Marco-Brown JL, Butler M, Candal RJ (2023) Degradation of oxytetracycline and characterization of byproducts generated by Fenton or photo-Fenton like processes after adsorption on natural and iron(III)-modified montmorillonite clays. Environ Nanatechnol Monit Manage 19:100778. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.enmm.2023.100778\u003c/span\u003e\u003cspan address=\"10.1016/j.enmm.2023.100778\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCui S, Qi Y, Zhu Q, Wang C, Sun H (2023) A review of the influence of soil minerals and organic matter on the migration and transformation of sulfonamides. Sci Total Environ 861:160584. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.scitotenv.2022.160584\u003c/span\u003e\u003cspan address=\"10.1016/j.scitotenv.2022.160584\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ede Souza RB, Guimar\u0026atilde;es JR (2022) Effects of Avermectins on the Environment Based on Its Toxicity to Plants and Soil Invertebrates\u0026mdash;a. Rev Water Air Soil Pollution 233(7):259. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s11270-022-05744-0\u003c/span\u003e\u003cspan address=\"10.1007/s11270-022-05744-0\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDhillon GS, Rees KCJV (2017) Distribution of soil organic carbon in the light and heavy fractions for six shelterbelt species and their adjacent agricultural fields in Saskatchewan. Can J Soil Sci 97(4):732\u0026ndash;744. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1139/cjss-2017-0010\u003c/span\u003e\u003cspan address=\"10.1139/cjss-2017-0010\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDionisio AC, Rath S (2016) Abamectin in soils: Analytical methods, kinetics, sorption and dissipation. Chemosphere 151:17\u0026ndash;29. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.chemosphere.2016.02.058\u003c/span\u003e\u003cspan address=\"10.1016/j.chemosphere.2016.02.058\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDubinsky EA, Silver WL, Firestone MK (2010) Tropical forest soil microbial communities couple iron and carbon biogeochemistry. Ecology 91(9):2604\u0026ndash;2612. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1890/09-1365.1\u003c/span\u003e\u003cspan address=\"10.1890/09-1365.1\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFang L, Chen C, Li S, Ye P, Shi Y, Sharma G, Sarkar B, Shaheen SM, Lee SS, Xiao R, Chen X (2023) A comprehensive and global evaluation of residual antibiotics in agricultural soils: Accumulation, potential ecological risks, and attenuation strategies. Ecotoxicol Environ Saf 262:115175. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.ecoenv.2023.115175\u003c/span\u003e\u003cspan address=\"10.1016/j.ecoenv.2023.115175\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHenderson GS, Black PM, Rodgers KA, Rankin PC (1984) New data on New Zealand vivianite and metavivianite. NZ J Geol Geophys 27(3):367\u0026ndash;378. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1080/00288306.1984.10422304\u003c/span\u003e\u003cspan address=\"10.1080/00288306.1984.10422304\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIngerslev F, Halling-Sorensen B (2001) Biodegradability of metronidazole, olaquindox, and tylosin and formation of tylosin degradation products in aerobic soil\u0026ndash;manure slurries. Ecotoxicol Environ Saf 48(3):311\u0026ndash;320. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1006/eesa.2000.2026\u003c/span\u003e\u003cspan address=\"10.1006/eesa.2000.2026\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJi J, Zhu Q, Yang X, Wang C (2023) Review of biodegradation of sulfonamide antibiotics influenced by dissolved organic matter and iron oxides. J Environ Chem Eng 11(5):111020. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jece.2023.111020\u003c/span\u003e\u003cspan address=\"10.1016/j.jece.2023.111020\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKhan SA, Riaz ur R, Khan MA (1995) Adsorption of chromium (III), chromium (VI) and silver (I) on bentonite. Waste Manag 15(4):271\u0026ndash;282. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/0956-053X(95)00025-U\u003c/span\u003e\u003cspan address=\"10.1016/0956-053X(95)00025-U\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKonstantinidis KT, Rossell\u0026oacute;-M\u0026oacute;ra R, Amann R (2017) Uncultivated microbes in need of their own taxonomy. ISME J 11(11):2399\u0026ndash;2406. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/ismej.2017.113\u003c/span\u003e\u003cspan address=\"10.1038/ismej.2017.113\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKornilovych B, Kovalchuk I, Tobilko V, Ubaldini S (2020) Uranium Removal from Groundwater and Wastewater Using Clay-Supported Nanoscale Zero-Valent Iron. Metals 10(11):1421. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3390/met10111421\u003c/span\u003e\u003cspan address=\"10.3390/met10111421\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKrogh KA, Jensen GG, Schneider MK, Fenner K, Halling-S\u0026oslash;rensen B (2009) Analysis of the dissipation kinetics of ivermectin at different temperatures and in four different soils. Chemosphere 75(8):1097\u0026ndash;1104. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.chemosphere.2009.01.015\u003c/span\u003e\u003cspan address=\"10.1016/j.chemosphere.2009.01.015\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKrogh KA, S\u0026oslash;eborg T, Brodin B, Halling-S\u0026oslash;rensen B (2008) Sorption and mobility of ivermectin in different soils. J Environ Qual 37(6):2202\u0026ndash;2211. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.2134/jeq2007.0592\u003c/span\u003e\u003cspan address=\"10.2134/jeq2007.0592\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLalonde K, Mucci A, Ouellet A, G\u0026eacute;linas Y (2012) Preservation of organic matter in sediments promoted by iron. Nature 483(7388):198\u0026ndash;200. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/nature10855\u003c/span\u003e\u003cspan address=\"10.1038/nature10855\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi Z, Kirk Jones H, Zhang P, Bowman RS (2007) Chromate transport through columns packed with surfactant-modified zeolite/zero valent iron pellets. Chemosphere 68(10):1861\u0026ndash;1866. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.chemosphere.2007.03.011\u003c/span\u003e\u003cspan address=\"10.1016/j.chemosphere.2007.03.011\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiebig M, Fernandez \u0026Aacute;A, Bl\u0026uuml;baum-Gronau E, Boxall A, Brinke M, Carbonell G, Egeler P, Fenner K, Fernandez C, Fink G, Garric J, Halling-S\u0026oslash;rensen B, Knacker T, Krogh KA, K\u0026uuml;ster A, L\u0026ouml;ffler D, Cots M\u0026Aacute;P, Pope L, Prasse C, R\u0026ouml;mbke J, R\u0026ouml;nnefahrt I, Schneider MK, Schweitzer N, Tarazona JV, Ternes TA, Traunspurger W, Wehrhan A, Duis K (2010) Environmental risk assessment of ivermectin: A case study. Integr Environ Assess Manag 6(S1):567\u0026ndash;587. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1002/ieam.96\u003c/span\u003e\u003cspan address=\"10.1002/ieam.96\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu Je, Zhang X, Zhou Z (2019) Quantifying effects of root systems of planted and natural vegetation on rill detachment and erodibility of a loessial soil. Soil Tillage Res 195:104420. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.still.2019.104420\u003c/span\u003e\u003cspan address=\"10.1016/j.still.2019.104420\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLofrano G, Libralato G, Meric S, Vaiano V, Sacco O, Venditto V, Guida M, Carotenuto M (2020) 1 - Occurrence and potential risks of emerging contaminants in water. Visible Light Active Structured Photocatalysts for the Removal of Emerging Contaminants. O. Sacco and V. Vaiano, Elsevier: 1\u0026ndash;25\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMarco-Brown JL, Valiente R, Ramos CP, Fern\u0026aacute;ndez MA, Candal R (2021) Stable nZVI-based nanocomposites for adsorption and reduction processes: The case of U(VI) removal. Environ Nanatechnol Monit Manage 16:100563. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.enmm.2021.100563\u003c/span\u003e\u003cspan address=\"10.1016/j.enmm.2021.100563\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMesa L, Guti\u0026eacute;rrez MF, Montalto L, Perez V, Lifschitz A (2020) Concentration and environmental fate of ivermectin in floodplain wetlands: An ecosystem approach. Sci Total Environ 706:135692. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.scitotenv.2019.135692\u003c/span\u003e\u003cspan address=\"10.1016/j.scitotenv.2019.135692\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMesa L, Mayora G, Saigo M, Giri F (2015) Nutrient Dynamics in Wetlands of the Middle Paran\u0026aacute; River Subjected to Rotational Cattle Management. Wetlands 35(6):1117\u0026ndash;1125. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s13157-015-0699-2\u003c/span\u003e\u003cspan address=\"10.1007/s13157-015-0699-2\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMesa LM, H\u0026ouml;rler J, Lindt I, Guti\u0026eacute;rrez MF, Negro L, Mayora G, Montalto L, Ballent M, Lifschitz A (2018) Effects of the Antiparasitic Drug Moxidectin in Cattle Dung on Zooplankton and Benthic Invertebrates and its Accumulation in a Water-Sediment System. Arch Environ Contam Toxicol 75(2):316\u0026ndash;326. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s00244-018-0539-5\u003c/span\u003e\u003cspan address=\"10.1007/s00244-018-0539-5\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMishra A, Mehta A, Basu S (2018) Clay supported TiO2 nanoparticles for photocatalytic degradation of environmental pollutants: A review. J Environ Chem Eng 6(5):6088\u0026ndash;6107. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.jece.2018.09.029\u003c/span\u003e\u003cspan address=\"10.1016/j.jece.2018.09.029\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMurad E, Cashion J (2004) M\u0026ouml;ssbauer Spectroscopy of Environmental Materials and Their Industrial Utilization. Springer, New York, NY\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNavarro M, Alonso LL, Capparelli AL, Marino DJG (2022) Mobilization of ionophore antibiotics and glyphosate after a rainfall simulation on agricultural soils amended with poultry litter. Agric Water Manage 274:107963. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.agwat.2022.107963\u003c/span\u003e\u003cspan address=\"10.1016/j.agwat.2022.107963\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eParks DH, Chuvochina M, Rinke C, Mussig AJ, Chaumeil P-A, Hugenholtz P (2021) GTDB: an ongoing census of bacterial and archaeal diversity through a phylogenetically consistent, rank normalized and complete genome-based taxonomy. Nucleic Acids Res 50(D1):D785\u0026ndash;D794. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1093/nar/gkab776\u003c/span\u003e\u003cspan address=\"10.1093/nar/gkab776\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePeluso J, Chehda AM, Olivelli MS, Ivanic FM, P\u0026eacute;rez Coll CS, Gonzalez F, Valenzuela L, Rojas D, Cristos D, Butler M, Candal RJ, Aronzon CM (2023) Metals, pesticides, and emerging contaminants on water bodies from agricultural areas and the effects on a native amphibian. Environ Res 226:115692. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.envres.2023.115692\u003c/span\u003e\u003cspan address=\"10.1016/j.envres.2023.115692\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePereyra F, Baumann V, Altinier MV, Ferrer J, Pablo T (2004) G\u0026eacute;nesis de suelos y evoluci\u0026oacute;n del paisaje en el delta del r\u0026iacute;o Paran\u0026aacute;. Revista de la Asociaci\u0026oacute;n Geol\u0026oacute;gica Argentina 59:229\u0026ndash;242\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePoeplau C, Aronsson H, Myrbeck \u0026Aring;, K\u0026auml;tterer T (2015) Effect of perennial ryegrass cover crop on soil organic carbon stocks in southern Sweden. Geoderma Reg 4:126\u0026ndash;133. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.geodrs.2015.01.004\u003c/span\u003e\u003cspan address=\"10.1016/j.geodrs.2015.01.004\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePoggenburg C, Mikutta R, Schippers A, Dohrmann R, Guggenberger G (2018) Impact of natural organic matter coatings on the microbial reduction of iron oxides. Geochim Cosmochim Acta 224. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.gca.2018.01.004\u003c/span\u003e\u003cspan address=\"10.1016/j.gca.2018.01.004\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRancourt D (1998) Recoil-M\u0026ouml;ssbauer Spectral Analysis Software for Windows. Department of Physics, University of Ottawa, Ontario\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRen X, Yan N, Chen S, Yao J, Liu J (2022) Remediation of arsenic-containing ferrihydrite in soil using iron- and sulfate-reducing bacteria: Implications for microbially-assisted clean technology. J Environ Chem Eng 10(6):108876. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.jece.2022.108876\u003c/span\u003e\u003cspan address=\"10.1016/j.jece.2022.108876\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRice EW, Baird RD, Eaton AD (2017) Standard methods for the examination of water and wastewater. American Water Works Association, Water Environment Federation, Washington, DC, American Public Health Association\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSchweizer SA, Bucka FB, Graf-Rosenfellner M, K\u0026ouml;gel-Knabner I (2019) Soil microaggregate size composition and organic matter distribution as affected by clay content. Geoderma 355:113901. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.geoderma.2019.113901\u003c/span\u003e\u003cspan address=\"10.1016/j.geoderma.2019.113901\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSeverini MDF, Carbone ME, Villagran DM, Marcovecchio JE (2018) Toxic metals in a highly urbanized industry-impacted estuary (Bahia Blanca Estuary, Argentina): spatio-temporal analysis based on GIS. Environ Earth Sci 77(10):393. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s12665-018-7565-5\u003c/span\u003e\u003cspan address=\"10.1007/s12665-018-7565-5\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSheng G, Shao X, Li Y, Li J, Dong H, Cheng W, Gao X, Huang Y (2014) Enhanced Removal of Uranium(VI) by Nanoscale Zerovalent Iron Supported on Na-Bentonite and an Investigation of Mechanism. J Phys Chem A 118(16):2952\u0026ndash;2958. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/jp412404w\u003c/span\u003e\u003cspan address=\"10.1021/jp412404w\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSigua GC (2010) Sustainable cow-calf operations and water quality: a review. Agron Sustain Dev 30:631\u0026ndash;648\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStefaniuk M, Oleszczuk P, Ok YS (2016) Review on nano zerovalent iron (nZVI): From synthesis to environmental applications. Chem Eng J 287:618\u0026ndash;632. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.cej.2015.11.046\u003c/span\u003e\u003cspan address=\"10.1016/j.cej.2015.11.046\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVerd\u0026uacute; JR, Lobo JM, S\u0026aacute;nchez-Pi\u0026ntilde;ero F, Gallego B, Numa C, Lumaret J-P, Cortez V, Ortiz AJ, Tonelli M, Garc\u0026iacute;a-Teba JP, Rey A, Rodr\u0026iacute;guez A, Dur\u0026aacute;n J (2018) Ivermectin residues disrupt dung beetle diversity, soil properties and ecosystem functioning: An interdisciplinary field study. Sci Total Environ 618:219\u0026ndash;228. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.scitotenv.2017.10.331\u003c/span\u003e\u003cspan address=\"10.1016/j.scitotenv.2017.10.331\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVokř\u0026aacute;l I, Michaela Š, Radka P, Jiř\u0026iacute; L, Luk\u0026aacute;š P, Dominika S, Kateřina L, Barbora S, Lenka S (2019) Ivermectin environmental impact: Excretion profile in sheep and phytotoxic effect in Sinapis alba. Ecotoxicol Environ Saf 169:944\u0026ndash;949. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.ecoenv.2018.11.097\u003c/span\u003e\u003cspan address=\"10.1016/j.ecoenv.2018.11.097\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang M, Cheng W, Wan T, Hu B, Zhu Y, Song X, Sun Y (2019) Mechanistic investigation of U(VI) sequestration by zero-valent iron/activated carbon composites. Chem Eng J 362:99\u0026ndash;106. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.cej.2018.12.138\u003c/span\u003e\u003cspan address=\"10.1016/j.cej.2018.12.138\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang Y, Yu W, Chang Z, Gao C, Yang Y, Zhang B, Wang Y, Xing B (2022) Effects of dissolved organic matter on the adsorption of norfloxacin on a sandy soil (fraction) from the Yellow River of Northern China. Sci Total Environ 848:157495. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.scitotenv.2022.157495\u003c/span\u003e\u003cspan address=\"10.1016/j.scitotenv.2022.157495\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZafar Z, Fatima R, Kim J-O (2021) Effect of HCl treatment on physico-chemical properties and photocatalytic performance of Fe\u0026ndash;TiO2 nanotubes for hexavalent chromium reduction and dye degradation under visible light. Chemosphere 284:131247. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.chemosphere.2021.131247\u003c/span\u003e\u003cspan address=\"10.1016/j.chemosphere.2021.131247\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhao X, Teng Z, Wang G, Luo W, Guo Y, Ji X, Hu W, Li M (2023) Anaerobic syntrophic system composed of phosphate solubilizing bacteria and dissimilatory iron reducing bacteria induces cadmium immobilization via secondary mineralization. J Hazard Mater 446:130702. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.jhazmat.2022.130702\u003c/span\u003e\u003cspan address=\"10.1016/j.jhazmat.2022.130702\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"environmental-processes","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"enpr","sideBox":"Learn more about [Environmental Processes](https://www.springer.com/journal/40710)","snPcode":"40710","submissionUrl":"https://submission.nature.com/new-submission/40710/3","title":"Environmental Processes","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Antiparasitic drugs, wetlands, livestock, soil organic matter","lastPublishedDoi":"10.21203/rs.3.rs-4824566/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4824566/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eGrazing activities in wetlands ecosystems lead to the alteration of nutrients dynamics and the contamination of soils and waters with veterinary products, among other negative impacts. The objective of this work was to determine the presence and mobility of Ivermectin (IVM), an antiparasite compound used in livestock, in soils from three cattle fields located in the lower Delta del Paran\u0026aacute;. Its mobility was correlated with the content of iron, different fractions of organic matter (OM) and clays.\u003c/p\u003e \u003cp\u003eResults indicated that upper and middle zones of fields contained the highest content of clays and hematite (1.51 and 0.35 g/kg, respectively) and presented the highest amount of labile OM (3.70 and 2.93%, respectively), with 23.50 and 14.25 ppm of IVM, respectively. The low and anaerobic zone with high iron content (25 g/kg) and no hematite, presented 16 ppm of labile OM and 16.06 ppm of IVM. Results suggested a high mobility of IVM from upper to lower zones; and a high concentration of soluble IVM in the lower zones (2.87 ppm) compared to the upper topographies (0.45 and 1 ppm).\u003c/p\u003e \u003cp\u003eThe presence of this drug was strongly influenced by its interaction with the type of OM and the mineralogical composition of soils. This is the first time that IVM was reported to be associated to a mobile and soluble fraction of organic matter, representing a threatening situation to water courses. This study allowed to explain the occurrence and fate of the contaminant in wetlands accordingly to the physicochemical characterization of soils.\u003c/p\u003e","manuscriptTitle":"Ivermectin mobility in Delta del Paraná wetlands: influence of topography and soil geochemical features","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-08-27 15:42:26","doi":"10.21203/rs.3.rs-4824566/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-11-29T20:15:40+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-09-12T16:56:21+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"124847948797629144054528624314715133628","date":"2024-08-28T14:32:23+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-08-28T01:07:17+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"222735438281602100166994577701573224052","date":"2024-08-26T09:05:25+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"135147534798226955519812542180044256672","date":"2024-08-19T11:50:40+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"238510339600418058556537962807966533075","date":"2024-08-19T11:22:56+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-08-17T06:58:23+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-07-30T16:03:40+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-07-30T12:16:22+00:00","index":"","fulltext":""},{"type":"submitted","content":"Environmental Processes","date":"2024-07-29T22:30:05+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"environmental-processes","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"enpr","sideBox":"Learn more about [Environmental Processes](https://www.springer.com/journal/40710)","snPcode":"40710","submissionUrl":"https://submission.nature.com/new-submission/40710/3","title":"Environmental Processes","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"20f767ec-d19f-4e54-8ef2-7ae7fca1ab02","owner":[],"postedDate":"August 27th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-04-07T16:04:05+00:00","versionOfRecord":{"articleIdentity":"rs-4824566","link":"https://doi.org/10.1007/s40710-025-00760-8","journal":{"identity":"environmental-processes","isVorOnly":false,"title":"Environmental Processes"},"publishedOn":"2025-03-31 15:57:32","publishedOnDateReadable":"March 31st, 2025"},"versionCreatedAt":"2024-08-27 15:42:26","video":"","vorDoi":"10.1007/s40710-025-00760-8","vorDoiUrl":"https://doi.org/10.1007/s40710-025-00760-8","workflowStages":[]},"version":"v1","identity":"rs-4824566","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4824566","identity":"rs-4824566","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}