Assessment Of Level Of Polychlorinated Biphenyls (PCBs) In Soil And Edible Crops From River Ala Floodplain In Akure

Assessment Of Level Of Polychlorinated Biphenyls (PCBs) In Soil And Edible Crops From River Ala Floodplain In Akure | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Assessment Of Level Of Polychlorinated Biphenyls (PCBs) In Soil And Edible Crops From River Ala Floodplain In Akure Taiwo Abe, Ademola Festus Aiyesanmi, Omotoyosi Blessing Ojonukpe This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4061550/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Flooding is one significant process that contributes to the movement of soil and sediments with the pollutants present in it along the river bank. With higher velocities of water, flooding can take contamination downstream. The soil, edible crops (rice and vegetables) samples were collected from Ala river floodplain in Ondo State and analyzed for their physico-chemical characteristics and level of Polychlorinated biphenyls present. The concentrations of nineteen (19) polychlorinated biphenyls (PCBs) were analyzed in soils collected at nine different sites along the floodplain and edible crops collected from six of the sites/ location using Gas Chromatography Mass Spectrometer (GC-MS) to determine the level of contamination of the floodplain and potential risks to the ecosystem and humans. The Ʃ-19 PCB concentrations in the floodplain soils varied between not detected (nd) -60 µg kg −1 , n.d – 60 µg kg −1 in vegetables and not detected to 80 µg kg −1 in rice across different locations. Higher concentration values were recorded in rice which suggests plants uptake and bioaccumulation potentials.The concentration of di to tetra homologues are more predominant in the samples. The concentration is lower than the value of permissible limit 2mg kg -1 recommended by Canadian Soil Quality Guideline (CSQG) and United States Environmental Protection Agency (US EPA). Dioxin-like PCBs were not detected Environmental Chemistry Poly chlorinated biphenyls PCBs floodplain edible crops Figures Figure 1 Figure 2 Figure 3 INTRODUCTION Polychlorinated biphenyls (PCBs) belong to a category of synthetic organic compounds called chlorinated hydrocarbons. These compounds encompass any chemical within the biphenyl molecule that has undergone varying degrees of chlorination. PCBs do not occur naturally and lack any known natural sources (Kakareka et al., 2015). They are part of the group of persistent organic pollutants, which consists of synthetic aromatic compounds with a general chemical structure denoted as C 12 H 10−x Cl x , (Grittini et al., 1995). Since their commercial production began in 1930, PCBs have primarily been used as coolants, lubricants, and fluids in electrical transformers and capacitors under the trade names Aroclor, Clophen, Fenclor, Kanechlor, Phenoclor, and Sovolin, among others ( Igbo et al., 2018: Takasuga et al., 2006). PCBs are widespread synthetic organic pollutants that are capable of exhibiting eco-toxicity effects far away from their point of emission due to their ability to undergo long distance migration (Iwegbue et al., 2020a; Ololade et al., 2021). These compounds are environmentally stable (i.e. they are resistant to microbial and photo-degradation), survives high temperature and resist incineration, difficult to reduce or oxidized, lipophilic and have the capacity to bio-accumulate in organs and tissues of organisms, and magnify through the food chain (Nouira et al. , 2013; Unyimadu , 2017) Floodplains are unique ecological habitats that connect riverside natural areas with adjacent leveled regions (Thonon, 2006). Due to their high nutrient and organic matter contents, these eco-zones are actively farmed all over the world (Aziza et al., 2021). The majority of rivers are polluted, and during flooding events the related pollutants are carried by suspended sediment to their floodplains. Such overbank deposits may enhance the floodplain's pollutant burdens. The primary sources of pollutants in the floodplains are flooding events and atmospheric inputs. Most floodplains serve as a sediment reservoir over a period of years and centuries. Nutrients, organic materials, and pollutants such metals, polycyclic aromatic hydrocarbons, polychlorinated biphenyls (PCBs), pesticides, polybrominated diphenyl ethers (PBDEs), dioxins, and furans are abundant in these sediments that have been accumulated (Iwegbue et al., 2020a). Due to the extensive cultivation of floodplain soils, humans are exposed to toxins in them via the soil-human, soil-plant-human, or soil-plant-animal-human interface (Iwegbue et al., 2020b; Maliszewska-Kordybach et al ., 2013). Soil acts as a sink for environmental pollutants, especially hydrophobic organic contaminants (HOCs) including many POPs, due to their highly hydrophobic nature and low aqueous solubility. Hydrophobicity is important namely for the catchment of the nonpolar organic pollutants including PAHs, PCBs and organochlorine pesticides (OCPs) and determines the fate of PCBs in and around the biosphere. PCBs in the river ecosystem are transported as dissolved, or bound to different-sized particles. But due to their overall low solubility, POPs tend to appear mainly in association with particulate matter. Ala River is one of the major tributaries of River Ogbese in South-western Nigeria. The river has a total length of about 58 km, out of which about 14.8 km is within Akure Township (Ayeni et al., 2011). The river water is used for domestic and industrial purposes. It is a permanent river which floods during the rainy season. It took its source from the North western part of Akure town and flows toward the South-eastern part of the town having its upstream at Aule, Okuta Elerinla while rural towns such as Ilado, Ehinala, Ajegunle, Owode, Aiyetoro and Araromi are located downstream. Akure experiences a climate marked by elevated temperatures and significant humidity, encompassing two distinct seasons: the wet and dry seasons. The yearly precipitation averages around 1524mm, while annual temperatures fluctuate between 28°C and 31°C, maintaining an average annual relative humidity of approximately 80%. Particularly during periods of substantial rainfall, many particles settle down to the sediment layer, which thus serve as a long-term reservoir and under specific conditions make the soil a temporarily a significant source of contaminants (Schwartz et al ., 2006). Possible erosion during floods events leads to the transfer of contaminated sediments to the oxidized water column, which generally enhances bioavailability and toxicity of pollutants. Thus, delayed and harmful effects linked to mobilization of chemical compounds that have been previously bounded to sediments can occur after floods. The river sediments can serve as a large potential source of contaminants for a long time after the maximal water contamination, when the concentration in water column has already decreased. These facts lead to the denomination of river sediments containing toxic compounds as potential chemical time bombs (Aziza et al., 2021). Due to the high risk potential, it will be necessary to quantify the concentrations of PCBs and identify their sources and variations in soils, in addition, determine the possible ecological and human health risks arising from these contaminants. MATERIALS AND METHODS Sampling The study was carried out in Ala River. Samples were carefully collected at different points along the river flood plain at nine locations in December 2021 when the flood water had receded completely into the river channel. The Soil samples were collected from nine locations namely (Aule, Ayedun, Alagbaka, Fiwasaye, Sijuwade, St. Thomas, Okuta Elerinla, Barracks and Adebowale) along the floodplains of Ala River with the aid of soil auger to a depth 0-20 cm. At each site, random samples of soil were collected at 100m from each other; the random samples were wet at the point of collection. and stored in foil paper, it was air dried, combined and quartered to form a composite. Rice samples were collected from four locations in dry form, these are Aule A, Barracks C, Adebowale D, and Okuta Elerinla G. Vegetable samples were gotten from six locations namely Aule, Ayedun, Adebowale, Alagbaka, Okuta Elerinla and St. Thomas. The vegetables were uprooted in green and wet form, sorting was done to separate root from stem, the leave and stem was air dried and stored for analysis. Laboratory samples were air-dried for two weeks. They were then ground into fine particles in a mortar, sieved through a 2 mm mesh and quartered to get a composite sample. The soil and food samples were analyzed in duplicate. Soil pH Determination The pH of the soil sample was determined using a pH meter that had been calibrated with buffer solutions at pH 4 and 9. To create a soil-water solution in a 1:2 ratio, 5 grams of soil sample were measured and mixed thoroughly with 10 cm 3 of distilled water in a beaker. This mixture was allowed to equilibrate for 1 hour, with stirring at 15-minute intervals. The pH value of this solution was then measured using a Jenway 2015 pH glass electrode system. Determination of Soil Organic Matter The total organic carbon content of the samples was evaluated according to the Walkley and Black (Walkley and Black, 1934). A 1-gram sample of air-dried soil was carefully weighed and placed into a 250 cm 3 conical flask. Next, 10 cm 3 of a 0.167 M K 2 Cr 2 O 7 solution (prepared by dissolving 49.14 g of K 2 Cr 2 O 7 in 1 liter of distilled water) was added to the flask and gently swirled to mix. Subsequently, 20 cm 3 of concentrated sulfuric acid was added to the mixture, swirled to ensure thorough mixing, and then left to stand on a pad within a fume cupboard for a period of 30 minutes. Subsequently, 100 cm 3 of distilled water was introduced into the mixture, followed by the addition of 3 drops of ferroin indicator. The content was then subjected to titration using a 0.5 M iron (II) ammonium sulfate solution until the color changed was observed from green to dark green shade. Once this transition occurred, ferrous sulfate was cautiously added drop by drop until the color shifted sharply from green to a distinct brownish-red colour. A blank titration was also performed following the same procedure in the absence of the sample. %TOM = %TOC X 1.724 Where, B represents the blank titre value.. T is the sample titre value. (B-T) is the difference between the blank titre volume and sample titre volume used. M is the molarity of ferrous sulphate used. W is the weight in gram of the sample. % TOC is the percent amount of total organic carbon of the sample. %TOM is the percent amount of total organic matter in the sample Source; Schulte 1995 Determination of Particle Size A 51-gram air-dried soil sample was carefully placed in a 250 cm 3 beaker and 100 cm 3 of a 5% sodium hexametaphosphate solution (calgon) was added to the beaker and left to soak overnight. Afterward, the suspension was stirred, and the entire mixture was quantitatively transferred to a sedimentation cylinder. The cylinder was then filled up to the 1-liter mark using distilled water. To ensure thorough mixing and to dislodge the sediment, a stirrer with a circular end was inserted into the cylinder and moved both upwards and downwards within the cylinder. This process was carried out to achieve a homogeneous mixture. Stirring was concluded with two deliberate and gradual strokes. To eliminate the foam present on the surface of the suspension, a small amount of isopropyl alcohol was added. A blank determination tank was prepared and treated in the same manner as the sample sedimentation tank. Subsequently, a hydrometer was carefully lowered into the sedimentation tank, and its reading was noted after forty seconds (Ra40 secs). This procedure was repeated two hours later, and the temperature of the suspension was also recorded. The percentage sand, silt and clay were thus calculated Ra = 40 seconds blank hydrometer reading. Rb = 2 hours blank hydrometer reading. Rc = 40 seconds correction factor (temp >20ºC x 0.360) Rd = 2 hours correction factor (temp>20ºC x 0.360) W = weight of soil. %Sand + %Silt + %Clay = 100 Sheldrick and Wang 1993 Extraction of PCBs in soil samples 10 g aliquot of well mixed soil sample was weighed into a solvent rinsed 200 ml beaker, the sample was spiked with 50 ml of 50:50 solvent mix of acetone and dichloromethane in 500 ml volumetric flask transferred to a sonicator for 20 minutes at 40 0 C. The extract was filtered into a well labelled clean 100 ml round bottom flask using Whatman No. 41 filter paper. The process was repeated with an additional 50 ml solvent mix and filtered. The extract was concentrated to 2 ml with the aid of a rotary evaporator and the solvent was interchanged with n-Hexane and re-concentrated to 2 ml using gentle stream of Nitrogen gas. The sample extract was transferred to a 2 ml sample vials using a graduated pipette, ready for clean-up. Standard operating procedure was in accordance to Aziza et al., (2021) with little modification. Cleanup of soil sample extracts The concentrated extract was subjected to purification in a 100-200mesh multi-layer silica gel (which had earlier been activated at 130 o C in the oven for 16 hrs, cooled in a desiccator before packing the polypropylene cartridge for analysis) and alumina column consisting of 2 g of anhydrous Na 2 SO 4 , 4 g of alumina and 3 g of silica gel packed from top to bottom. The 50 ml polypropylene cartridge was mounted on the retort stand and the base was plug with sterile cotton wool. The cartridge was conditioned with 10 ml n-hexane, the eluate was collected as waste in a beaker. 1-2 ml of the sample extract was added to the head of the column using a narrow tip 2 ml graduated pipette. The column was eluted with 5 ml of n-hexane, the eluate was collected in a clean 100 ml flask. Before the column dried up, 40 ml of Hexane/Diethyl ether (50:50) was added to the head of the cartridge. This fraction was also collected and added to the 100 ml flask. The combined fraction was evaporated using rotary evaporator to 2 ml at 40 o C. The extract was solvent exchanged into n-hexane by addition of 5 ml n-hexane. The extract volume was reduced to 2 ml using gentle stream of N 2 gas. This was transferred into a 2 ml GC Vials with screw cap, ready for GCMS analysis (Aziza et al., 2021, Hakanson 1980). Clean up of food sample extracts (Rice and vegetables) The concentrated extract was subjected to purification in a 100-200 mesh multi-layer silica gel (which had earlier been activated at 130 o C in the oven for 16hrs, cooled in a desiccator before packing the polypropylene cartridge for analysis) and alumina column consisting of 2 g of anhydrous Na 2 SO 4 , 4 g of alumina and 3 g of silica gel packed from top to bottom. The 50 ml polypropylene cartridge was mounted on the retort stand and the base was plug with sterile cotton wool. The cartridge was conditioned with 10 ml n-hexane, the eluate was collected as waste in a beaker. 1-2 ml of the sample extract was added to the head of the column using a narrow tip 2 ml graduated pipette. The column was eluted with 5 ml of n-hexane, the eluate was collected in a clean 100 ml flask. Before the column dried up, 40 ml of Hexane/Diethyl ether (50:50) was added to the head of the cartridge. This fraction was also collected and added to the 100 ml flask. The combined fraction was evaporated using rotary evaporator to 2 ml at 40 o C. The extract was solvent exchanged into n-hexane by addition of 5 ml n-hexane. The extract volume was reduced to 2 ml using gentle stream of N 2 gas. This was transferred into a 2 ml GC Vials with screw cap, ready for GCMS analysis (Olatunji 2019). GC-MS instrumentation and analysis The analysis was carried out using a Hewlett Packard Model 5890 Series II plus gas chromatograph, which was equipped with a Hewlett Packard 5972 Mass Selective Detector (GC/MS). For the analysis, a HP-5 fused silica capillary column was utilized, with specifications including a length of 30 meters, an internal diameter of 0.25 mm, and a film thickness of 0.25 µm. This column was coated with a mixture of 5% phenyl and 95% methylpolysiloxane. The temperature program for the column oven was initiated at 120 °C with a holding time of 1 minute. It was then raised to 190 °C at a rate of 20 °C per minute, further increased to 230 °C at a rate of 5°C per minute, and finally elevated to 300 °C at a rate of 25°C per minute, with a holding time of 10 minutes. The injector and detector temperatures were maintained at 280 °C and 300 °C, respectively, throughout the analysis. Helium was employed as the carrier gas, maintaining a consistent flow rate of 0.8 ml per minute. The injection process was carried out in split-less mode. For mass spectrometry, the instrument operated in electron impact ionization (EI) positive-mode, utilizing automatic gain control. The storage window was configured to encompass the mass-to-charge ratio (m/z) range from 200 to 500, employing selected ion monitoring (SIM). During data acquisition, the scan time was set at 1.0 second, with four micro-scans performed each second. The quantification of the target compounds was achieved by monitoring the characteristic ions at m/z 258, 292, 326, 362, 396, and 430. These ions were selected considering the parent ions of the group of PCBs present in PCB congener mixture Calibration was performed by injections of standard solution of MIX 19 (PCB-1, 5, 18, 31, 52, 44, 66, 101, 87, 110, 151, 153, 141, 138, 187, 183, 170, 180, 206) at 6 calibration levels (0.05, 0.1, 0.25, 0.5, 1 and 2 µg ml -1 ). In the investigated PCBs, no peak areas were detected in the blank samples, and the limit of detection was established as the concentration at which a signal-to-noise ratio of 3 was achieved. (LOD = 0.1 µg kg-1). Linearity was investigated within the range between: 0.01–1 µg ml-1 and the R 2 values were found to be between 0.992 and 0.999. RESULTS AND DISCUSSIONS Physicochemical Properties of soil The physicochemical properties of the floodplain soil samples are presented in Table 4.1. The pH levels of the soil samples ranged from 4.85 to 7.54 across all the sampling locations, indicating that the soils are mildly acidic. This acidity can have an impact on the potential leaching of contaminants from the soil, primarily due to the soil-water partition coefficient. These pH values align with previous research conducted on the Ala River floodplain, as reported in earlier studies by Fadojumiti et al., ( 2017). The Total Organic Matter (TOM) content fell within the range of 6.04 to 14.77, with the highest value observed at site B-Ayedun. This finding confirms the presence of organic matter in the soil. PCBs, being hydrophobic chemicals with limited water solubility, tend to partition into the organic matter present in the soil. A noteworthy observation is the significant positive correlation observed between Total Organic Carbon (TOC) and the sum of PCBs (∑PCBs), with a correlation coefficient (r) of 0.828. This suggests that organic matter plays a crucial role in both the contribution to and fate of PCBs in the River Ala floodplain. The percentage of sand, clay and silt in the soil profiles ranged between 78.56 to 91.29, 7.76 to 16.73 and 0.95 to 6.6 respectively and referred to as sand clay silt. The soil texture is predominantly sand as represented in Table 1. Table: Physico-chemical properties of soil Key: A-Aule, B-Ayedun, C-Barracks, D- Adebowale, E- Alagbaka, F- Fiwasaye, G- Okuta Elerinla, H – St. Thomas, I – Sijuwade Distribution pattern of PCBs in soil samples A summary of the PCB concentrations measured in floodplain soil is presented in Table 1.. The PCB concentrations for the 19 congeners examined in these soils ranged from 20 µg kg -1 to 60 µg kg -1 across all sampling locations. These findings align with the values reported in Abata 2017. It's worth noting that while 19 PCB congeners were investigated in the samples, only 14 PCBs were identified in the soil. PCBs-1, 87, 151, 206, and 187 were not detected in the soil samples. The concentrations of PCBs in the floodplain soils exhibited significant variations compared to the concentrations of PCBs found in edible crops (rice and vegetables). The PCB homolog pattern in soils at different locations shows PCB 66 having the highest occurrence in Aule, Ayedun, Okuta Elerinla and Fiwasaye. Ayedun location B with the highest Organic matter content of 14.77 has ten PCBs present which are PCB 18, 31, 44, 52, 66, 87, 110, 138, 141, 153 and 170 at higher concentrations which could be as a result of affinity the hydrophobic organic pollutant PCBs to the soil. Tri and tetra homologues dominated in majority of the locations. Hexa PCBs 153 and 187 have highest concentrations of 60 µg kg -1 . Distribution pattern of PCBs in rice samples PCB congeners were analyzed in flood plain vegetables of Ala River and their observed concentrations are presented in Fig. 2. The mean concentration ranged between N.D – 60 µg kg −1 . In all the samples, nine (9) PCBs were not detected in vegetable samples. Only ten (10) were discovered. PCB patterns when characterized in terms of individual homolog, The PCB homolog pattern in vegetables at different locations has hexa PCBs as the major contributors and accounted for 58% to total PCBs and the contribution of remaining homolog is about 42%. The sum of all PCBs ranged in the interval 34.2 – 48.5 µg kg -1 . Site B Ayedun has the highest prevalent with 8PCBs investigated. Concentration of PCBS in rice samples A summary of the concentrations of PCBs sampled in rice is represented in Fig. 3. The PCBs concentration for the 19 congeners investigated in the rice sample ranged from not detected (ND) to 60 µg kg -1 for all sampling locations with six PCBs not detected. The concentration of PCBs in the rice is higher than concentration in soil which may result from plant uptake of PCBs into tissues and cells of plant which suggests its bioaccumulation potential. Homologue patterns of PCB as presented in figure 4.3 shows di - tetra PCBs as the major contributors and accounted for 62.42% to total PCBs and the contribution of remaining homolog is about 37.58%. Location Adebowale has the highest prevalent with seven (7) PCBs, Barracks has seven (7) PCBs present. PCB-126 concentration was below detection limit at all the locations, thus higher homologue PCB183 has the highest concentration. CONCLUSION Finally, this study established the environmental assessment and contamination of PCBs in floodplain soils and edible crops of Ala River, South-West Nigeria. It also revealed that the levels of PCBs falls within the acceptable limit standards for soil and edible crops. Dioxin like indicator PCBs were not discovered in the samples. . Consequently from the above findings, it was deducted that concerted effort needs to be made by the relevant authorities to reduce the levels so it doesn’t pose health risks to individuals and aquatic habitats. 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(2006). Isotope dilution analysis of polychlorinated biphenyl (PCBs) in transformer oil and global commercial PCB formulations by high resolution gas chromatography-high resolution mass spectrometry. Chemosphere , 62, 469–484Iwegbue et al., 2020a Thonon, I. (2006). Deposition of sediments and associated heavy metals on foodplains. Netherlands Geographical Studies 337. Koninklijk Nederlands Aardrijkskundig Genoostschap, Faculteit Geowetenschappen Universiteit Utrecht Unyimadu, J.P., (2017). Evaluation of contamination of River Niger by persistent organic pollutants (POPs) using sediment quality guidelines (SQGs). J. Coast. Zone Manag . 20 (2(Suppl)). https://doi.org/10.4172/2473-3350-C1-003 Walkley, A., & Black, I.A., 1934. An examination of the Degtjareff method for determining soil organic matter and a proposed modification of the chromic acid titration method. Soil Sci . 37, 29–38. Additional Declarations The authors declare no competing interests. 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These compounds encompass any chemical within the biphenyl molecule that has undergone varying degrees of chlorination. PCBs do not occur naturally and lack any known natural sources (Kakareka \u003cem\u003eet al.,\u003c/em\u003e 2015). They are part of the group of persistent organic pollutants, which consists of synthetic aromatic compounds with a general chemical structure denoted as C\u003csub\u003e12\u003c/sub\u003eH\u003csub\u003e10\u0026minus;x\u003c/sub\u003eCl\u003csub\u003ex\u003c/sub\u003e, (Grittini \u003cem\u003eet al.,\u003c/em\u003e 1995). Since their commercial production began in 1930, PCBs have primarily been used as coolants, lubricants, and fluids in electrical transformers and capacitors under the trade names Aroclor, Clophen, Fenclor, Kanechlor, Phenoclor, and Sovolin, among others ( Igbo \u003cem\u003eet al., \u003c/em\u003e2018: Takasuga \u003cem\u003eet al.,\u003c/em\u003e 2006). PCBs are widespread synthetic organic pollutants that are capable of exhibiting eco-toxicity effects far away from their point of emission due to their ability to undergo long distance migration (Iwegbue \u003cem\u003eet al., \u003c/em\u003e2020a; Ololade \u003cem\u003eet al., \u003c/em\u003e2021). These compounds are environmentally stable (i.e. they are resistant to microbial and photo-degradation), survives high temperature and resist incineration, difficult to reduce or oxidized, lipophilic and have the capacity to bio-accumulate in organs and tissues of organisms, and magnify through the food chain (Nouira \u003cem\u003eet al.\u003c/em\u003e, 2013; Unyimadu\u003cem\u003e, \u003c/em\u003e2017)\u003c/p\u003e\n\u003cp\u003eFloodplains are unique ecological habitats that connect riverside natural areas with adjacent leveled regions (Thonon, 2006). Due to their high nutrient and organic matter contents, these eco-zones are actively farmed all over the world (Aziza et al., 2021). The majority of rivers are polluted, and during flooding events the related pollutants are carried by suspended sediment to their floodplains. Such overbank deposits may enhance the floodplain\u0026apos;s pollutant burdens. The primary sources of pollutants in the floodplains are flooding events and atmospheric inputs. Most floodplains serve as a sediment reservoir over a period of years and centuries. Nutrients, organic materials, and pollutants such metals, polycyclic aromatic hydrocarbons, polychlorinated biphenyls (PCBs), pesticides, polybrominated diphenyl ethers (PBDEs), dioxins, and furans are abundant in these sediments that have been accumulated (Iwegbue et al., 2020a). Due to the extensive cultivation of floodplain soils, humans are exposed to toxins in them via the soil-human, soil-plant-human, or soil-plant-animal-human interface (Iwegbue \u003cem\u003eet al.,\u003c/em\u003e 2020b; Maliszewska-Kordybach \u003cem\u003eet al\u003c/em\u003e., 2013).\u003c/p\u003e\n\u003cp\u003eSoil acts as a sink for environmental pollutants, especially hydrophobic organic contaminants (HOCs) including many POPs, due to their highly hydrophobic nature and low aqueous solubility. Hydrophobicity is important namely for the catchment of the nonpolar organic pollutants including PAHs, PCBs and organochlorine pesticides (OCPs) and determines the fate of PCBs in and around the biosphere. PCBs in the river ecosystem are transported as dissolved, or bound to different-sized particles. But due to their overall low solubility, POPs tend to appear mainly in association with particulate matter.\u003c/p\u003e\n\u003cp\u003eAla River is one of the major tributaries of River Ogbese in South-western Nigeria. The river has a total length of about 58 km, out of which about 14.8 km is within Akure Township (Ayeni \u003cem\u003eet al., \u003c/em\u003e2011). The river water is used for domestic and industrial purposes. It is a permanent river which floods during the rainy season. It took its source from the North western part of Akure town and flows toward the South-eastern part of the town having its upstream at Aule, Okuta Elerinla while rural towns such as Ilado, Ehinala, Ajegunle, Owode, Aiyetoro and Araromi are located downstream. Akure experiences a climate marked by elevated temperatures and significant humidity, encompassing two distinct seasons: the wet and dry seasons. The yearly precipitation averages around 1524mm, while annual temperatures fluctuate between 28\u0026deg;C and 31\u0026deg;C, maintaining an average annual relative humidity of approximately 80%. Particularly during periods of substantial rainfall, many particles settle down to the sediment layer, which thus serve as a long-term reservoir and under specific conditions make the soil a temporarily a significant source of contaminants (Schwartz \u003cem\u003eet al\u003c/em\u003e., 2006). Possible erosion during floods events leads to the transfer of contaminated sediments to the oxidized water column, which generally enhances bioavailability and toxicity of pollutants. Thus, delayed and harmful effects linked to mobilization of chemical compounds that have been previously bounded to sediments can occur after floods. The river sediments can serve as a large potential source of contaminants for a long time after the maximal water contamination, when the concentration in water column has already decreased. These facts lead to the denomination of river sediments containing toxic compounds as potential chemical time bombs (Aziza \u003cem\u003eet al., \u003c/em\u003e2021). Due to the high risk potential, it will be necessary to quantify the concentrations of PCBs and identify their sources and variations in soils, in addition, determine the possible ecological and human health risks arising from these contaminants.\u003c/p\u003e"},{"header":"MATERIALS AND METHODS","content":"\u003cp\u003e\u003cstrong\u003eSampling\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study was carried out in Ala River. Samples were carefully collected at different points along the river flood plain at nine locations in December 2021 when the flood water had receded completely into the river channel. The Soil samples were collected from nine locations namely (Aule, Ayedun, Alagbaka, Fiwasaye, Sijuwade, St. Thomas, Okuta Elerinla, Barracks and Adebowale) along the floodplains of Ala River with the aid of soil auger to a depth 0-20 cm. At each site, random samples of soil were collected at 100m from each other; the random samples were wet at the point of collection. and stored in foil paper, it was air dried, combined and quartered to form a composite. Rice samples were collected from four locations in dry form, these are Aule A, Barracks C, Adebowale D, and Okuta Elerinla G. Vegetable samples were gotten from six locations namely Aule, Ayedun, Adebowale, Alagbaka, Okuta Elerinla and St. Thomas. The vegetables were uprooted in green and wet form, sorting was done to separate root from stem, the leave and stem was air dried and stored for analysis. Laboratory samples were air-dried for two weeks. They were then ground into fine particles in a mortar, sieved through a 2 mm mesh and quartered to get a composite sample. The soil and food samples were analyzed in duplicate.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSoil pH Determination\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe pH of the soil sample was determined using a pH meter that had been calibrated with buffer solutions at pH 4 and 9. To create a soil-water solution in a 1:2 ratio, 5 grams of soil sample were measured and mixed thoroughly with 10 cm\u003csup\u003e3\u003c/sup\u003e of distilled water in a beaker. This mixture was allowed to equilibrate for 1 hour, with stirring at 15-minute intervals. The pH value of this solution was then measured using a Jenway 2015 pH glass electrode system.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDetermination of Soil Organic Matter\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe total organic carbon content of the samples was evaluated according to the Walkley and Black (Walkley and Black, 1934). A 1-gram sample of air-dried soil was carefully weighed and placed into a 250 cm\u003csup\u003e3\u003c/sup\u003e conical flask. Next, 10 cm\u003csup\u003e3\u003c/sup\u003e of a 0.167 M K\u003csub\u003e2\u003c/sub\u003eCr\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e7\u003c/sub\u003e solution (prepared by dissolving 49.14 g of K\u003csub\u003e2\u003c/sub\u003eCr\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e7\u003c/sub\u003e in 1 liter of distilled water) was added to the flask and gently swirled to mix. Subsequently, 20 cm\u003csup\u003e3\u003c/sup\u003e of concentrated sulfuric acid was added to the mixture, swirled to ensure thorough mixing, and then left to stand on a pad within a fume cupboard for a period of 30 minutes. Subsequently, 100 cm\u003csup\u003e3\u003c/sup\u003e of distilled water was introduced into the mixture, followed by the addition of 3 drops of ferroin indicator. The content was then subjected to titration using a 0.5 M iron (II) ammonium sulfate solution until the color changed was observed from green to dark green shade. Once this transition occurred, ferrous sulfate was cautiously added drop by drop until the color shifted sharply from green to a distinct brownish-red colour. A blank titration was also performed following the same procedure in the absence of the sample.\u003c/p\u003e\n\u003cp\u003e\u003cimg src=\"data:image/png;base64,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\" width=\"368\" height=\"131\"\u003e\u003c/p\u003e\n\u003cp\u003e%TOM = %TOC X 1.724\u003c/p\u003e\n\u003cp\u003eWhere, B represents the blank titre value..\u003c/p\u003e\n\u003cp\u003eT is the sample titre value.\u003c/p\u003e\n\u003cp\u003e(B-T) is the difference between the blank titre volume and sample titre volume used.\u003c/p\u003e\n\u003cp\u003eM is the molarity of ferrous sulphate used.\u003c/p\u003e\n\u003cp\u003eW is the weight in gram of the sample.\u003c/p\u003e\n\u003cp\u003e% TOC is the percent amount of total organic carbon of the sample.\u003c/p\u003e\n\u003cp\u003e%TOM is the percent amount of total organic matter in the sample\u003c/p\u003e\n\u003cp\u003eSource; Schulte 1995\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDetermination of Particle Size\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA 51-gram air-dried soil sample was carefully placed in a 250 cm\u003csup\u003e3\u003c/sup\u003e beaker and 100 cm\u003csup\u003e3\u003c/sup\u003e of a 5% sodium hexametaphosphate solution (calgon) was added to the beaker and left to soak overnight. Afterward, the suspension was stirred, and the entire mixture was quantitatively transferred to a sedimentation cylinder. The cylinder was then filled up to the 1-liter mark using distilled water. To ensure thorough mixing and to dislodge the sediment, a stirrer with a circular end was inserted into the cylinder and moved both upwards and downwards within the cylinder. This process was carried out to achieve a homogeneous mixture. Stirring was concluded with two deliberate and gradual strokes. To eliminate the foam present on the surface of the suspension, a small amount of isopropyl alcohol was added. A blank determination tank was prepared and treated in the same manner as the sample sedimentation tank. Subsequently, a hydrometer was carefully lowered into the sedimentation tank, and its reading was noted after forty seconds (Ra40 secs). This procedure was repeated two hours later, and the temperature of the suspension was also recorded. The percentage sand, silt and clay were thus calculated\u003c/p\u003e\n\u003cp\u003e\u003cimg src=\"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAT4AAACiCAYAAADY66G8AAAVIUlEQVR4Ae2bgZHUOBBFSYEYSIEcCIEYSIEMyIAMiIAISIAEyIAc9upx928blTxjz3jssfVU5ZItS+rWl/Tc9uy+eTGpgAqowGAKvBlsvA5XBVRABV4En4tABVRgOAUE33BT7oBVQAUEn2tABVRgOAUE33BT7oBVQAUEn2tABVRgOAUE33BT7oBVQAUEn2tABVRgOAUE33BT7oBVQAUEn2tABVRgOAUE33BT7oBVQAUEn2tABVRgOAUE33BT7oBVQAUEn2tABVRgOAUE33BT7oBVQAUEn2tABVRgOAUE33BT7oBVQAUEn2tABVRgOAUE33BT7oBVQAUEn2tABVRgOAUE33BT7oBVQAUEn2tABVRgOAUE33BTvt6Af/z48fLx48eXnz9/rtfpgXr68uXLy6dPn15+/fp1IK91FQUEn+vgJgW+ffv28v79+5ffv3/f1P4IjQD7mzdv/hxTcKfOu3fvhoX/Eeax56Pg66li2UUF2Oxv377tQu/Dhw//wyLQAJBT4Lho6IE35/r5/fv3P2O95Ergt+QhQLTIsSRFz5oTcS+xu8TeLXXRC217CT+JkON/z3fWSeaGNfb58+deV3eXCb67JRyvAxbm169fuwNncbOwiQhJXLPAWcTPlOb6CZzw/1oC7ktAdgv4gAra5tWanGhzjn/X/Oc+8zr1gAJY2J9KmWf8mwIf5XlLiO+1Ln2wTrBFSsS9RNcp/9pywdcq4vVFBViwdfO1lbNYszm5DwRp80xprp9AZc7G40EAhOamW8BHm9YGkKjwmGu/V495Ajwt/LARYPXaUYZOtMPHnj9ZNxWeaFbXUtYJAEyi33bMuXdP/lyr8Z6R2HYTBbI4p4z1NievK23ExwZgM7HwWdhsgke91vR8nesnfgNJfIuvdWOm74C0dy91ao59jiUJoCQaSjs0bCM+fIm2+Ny2Sdte3sJvDvRqP4ypB76sm6pPNCMnxVbbH2NYO63f49oe2t9TKTC1sOMkGy4bjUWepzoLPymvbNwjZQPUaCB1H5XP8ZMIhk2Hn5wzHkDYA1bGkE18zW/66PUz1Q7b+BIdiaDQuY3QWm2xsfSBEvgBVHSqsJryL+XY64GP8hZg0Sw60K5tm3ZzdY0f13LBd00h7/+lwNTCplI2Jws8Bwu5XbQtPAKYuRssmyE2pvK/HC8Xc/0EeC1YGE82aunyf3i3Y00d2k35mfJ206cteYCWuuSAr35SoB7Rc8+/2tec8/g7NZ6pPqbWR+astqNvxpEHIDZbDdKONbJmEnxrqjlAXyxEooBeyubMIk3EUOtmsdcNy8Kf6rO2Xet8jp/Ywv82WqobtfqTcc0FBTpyzE34AYRJgBvAtb7Fh6rt3P5rvQA/8zf3gUQfjKmFF+X0iXa1r/gbzWKv+kJ/tFs7rd/j2h7a31MpkG81PaeIQOqH6CzsgJA27ULOJl4CgZ7tJWVz/KQ/QAMkk/IKWDdv7mWsvXupU3PGu2TM6IrfSbQNCGvZvZDIGDNn2FzyuotfPfDRH761elYY9uAY+xnjWrngW0vJQfohmmCxtlEFG56N2C566rKgkwJONgJ9ELXQhnKOPP1Tf+18rp/ZqPEdvxhfrlu/2PAV+u399pr6HHNSoFrrpyyAop82kuW6jQov2Wuhl7qBzxyoY29KBwAaiDL3nFf/KEPjAD6aV1jGp3tzwXevggO2B1R1EyIBZUCOo97j9YXFzKYisXlSlwXONYu/1nmkpLF9zU8Ax5H6bOZLG5BNXMd9bQzUnVs/upIDgyQ0w24tQ0vqBSBzYJX+GGsFacrJmatL48cuvsRX9KK/mug7euIfbVr/sEFb+iGfetDUfm85F3y3qDZ4mzyJ20U7qizZrEv0WAK+UXV95LgPCb48EeqT7pEibdE3ERFPufYpuYXtW2zgL0/4JZv9FjvP3oYohvU4FSk9u/+j+rcq+LII2MCEsW0CVCyS3mbhCRigtWE69+gzifZc3ws+IDO3D2wmTCdvx8A1ft+zAdDsKOBjLtCOV9l7xpw5PWLOaxivgO33ziOOZTSfX2mywsgBF2E/EOA833XSNWU90AR6WUD0UcHWgo/+6n2uWYDUW5KWgI/+A3M2O9c13WK/tucc/48EvtZ/r1XgKAqsBj6gVaMyNnEFEecAo5fY7IFK7lO3B8ncb8G39OMy/SwBX4U2flVAcc39NgqMr3NzwTdXKeupwH0KrAa+FgYVfLwK8Ro4BQaipanXxLStUGXIFXz11yTK27pTEi0BX+2zjjXRLWVzEvWBPOOlT/JExj3wEf1mfLUur1kZa375qmVTr59pcynHD5MKnFmB1cB3KeIDMGxujmz4bFbEBQbUYTMCwXbTshG5VxPXFTa0X7phl4BvKuLDZnymDn5NRbb4D/QAGXoxburGb3J8SkIj+swnAOqiXxLX9FUT7au29Z7nKqAC/yrwN03uVIVNWb/xASY2IZsxkRFQSxSXDR2zgDHRTd28AGEN8NHHtSMQik/JgUxexwOrjCPgxn/OGQPnbeIe9tGol1rwtXVaHdCX/qIjOaB8VLqmnfevry81ul2jNdf1quBjQyeiAxJsdK7ZkGzSGs1w3oMDg6OcBZLIr93w1OH+lhFfoILdgLyOgfIk/CUKbFNAVf2udXrg4wEAaDmwUe3QFsjGFvmUprGTPi7l+GFSgTMr8LpbHzDKREZ03QNfNhibEEjWRFkAQT2ua6r3KQdC6a/Wu3ROm9i4VK93L5Fs7lX/8IO+2wQ8W79rnbYdIEPDpJ4OgI6HCw+JR0Z78cFcBc6gwN80WXFE+SifLnvgyysfMGCTB35AhTJAQWo3fF4Za3QDaAIb+krb2O/lt4Iv0V+10YIvr8WtXWwCszrWjIM2FV6pSx/Y4rraoZx+AB9H+mlteq0CKvC3Ag8BH5uRDVyjKTYum5bIhPO8AuMOoMu3PepwHijmOxrliX7om+tEOvSR1+wlALgVfDWSjZz4xDgYO/1OQYjxBGD4CtRJ1GdMHIA7ZdShDCgyRs6jw59K//1gUoGZcnMVUIG+Ag8BH5u0F/GwudnIS+DUd3ud0lvAB3wAc5vyqhlItfcfeQ0op0D7SLv2rQJHVeAh4DuqGEfym0gR2AFiAG56DgXyWYYHYH0YcU5ZTYnmKa9vR7WO549R4O+ZeIwNe32AAtlgQC/fCx9gxi5vUKAX9efzTO0uny4qIOt9zx+ngOB7nLb2PKgCgC/fbpEgfwHQRnzUab/XDirZ5sMWfJtLrsGzK1DBlx/6Et1l7PzARxRIbtpeAcG3veZaPLkCfLtLxEfOwTe8GvER6REJmvZRQPDto7tWT6wA312BHdEefwFAXsHHee8vA04sydMNTfA93ZTo0NEVCPiAX364CPjy6sufP5n2U0Dw7ae9lk+qAODjbyvrH5UHfMCw9zeuJ5XiaYcl+J52anTsqAoAPr7nJdpjHAEfMCTqM+2rgODbV3+tn1ABwFejPYYY8PHrrml/BQTf/nOgByqgAhsrIPg2FlxzKqAC+ysg+PafAz1QARXYWAHBt7HgmlMBFdhfAcG3/xzogQqowMYKCL6NBdecCqjA/goIvv3nQA9UQAU2VkDwbSy45lRABfZXQPDtPwd6oAIqsLECgm9jwTWnAiqwvwKCb/850AMVUIGNFRB8GwuuORVQgf0VEHz7z4EeqIAKbKyA4NtYcM2pgArsr4Dg238O9EAFVGBjBQTfxoJrTgVUYH8FBN/+c6AHKqACGysg+DYWXHMqoAL7KyD49p8DPVABFdhYAcG3seCaUwEV2F8Bwbf/HOiBCqjAxgoIvo0F15wKqMD+Cgi+/edAD1RABTZWQPBtLLjmVEAF9ldA8O0/B3qgAiqwsQKCb2PBNacCKrC/AoJv/znQAxVQgY0VEHwbC645FVCB/RUQfPvPgR6ogApsrIDg21hwzamACuyvgODbfw70QAVUYGMFBN/GgmtOBVRgfwUE3/5zoAcqoAIbKyD4NhZccyqgAvsrIPj2nwM9UAEV2FgBwbex4JpTARXYXwHBt/8c6IEKqMDGCgi+jQXXnAqowP4KCL7950APVEAFNlZA8G0suOZUQAX2V0Dw7T8HeqACKrCxAoJvY8E1pwIqsL8Cgm//OdADFVCBjRUQfBsLrjkVUIH9FRB8+8+BHqiACmysgODbWHDNqYAK7K+A4Nt/DvRABVRgYwUE38aCa04FVGB/BQTf/nOgByqgAhsrIPg2FlxzKqAC+ysg+PafAz1QARXYWAHBt7HgmlMBFdhfAcG3/xw8xIMfP368fPz48eXnz58P6f+ZOv3y5cvLp0+fXn79+vVMbunLEysg+J54cm517du3by/v379/+f379+IuAOabN2/+HEeCJn6/e/fuaUFfdRXQi5fl6g0E3+qS7tshG+zt27dd6AVoNScqbAH5/fv3P31sNZIPHz78D9v4BriXgjfwa8dzaRzYpt3cVAEWX9H78+fPV7sgMgXOWyZsTvmGvtF+agysBXxmrOQ8VM+QBN8ZZrGMgYX89evXUvJ6yiJmASfiIGcxA7+a2CxtWb2/9jmgwq9sKq6xz2ZcmgAm/s9NS8FHv4CkAiwwnNI9vuAXr+RzEnODbz2IU8a9zGOvP6CGFuja04M+0Df+ZAy1bsoyL9yjP8qPngTf0Wew+M9GqGArt/6csnDrhqWQhc8mqgno1A1Q7z3iPBusbmQ2G2NZmoBPO8ZLfdwCPtoEGOkbm9c0Q9drcEx/5NhoP1kALMpa+7UdOmIrgOz5FX2pk0Sbql3s5z55hWUtP9r58pV1tBEO5G8W89SQexuWTcSCr4nFDYyIbIAPm6FukFp3jfMekLHdRnz4lCgGv3qbPxCd6+8t4MN2oiDGjy3KWqhlXPEVHZe+vgc+2OC4Br12PhhfD3zpt9anHr4m4W/7mkx/HEdPr6M8+kj0/88Cn1qU2ZzZsEQFLH7gUjcj59nEnNOOOr3Ns5bkdTNjD4DgQ3zFTl7TAxf8aTcl9QI+8jkJvebWrX4kOkUj/OfA96SAO33nOveX5IFU1Wlue8bXmzvK27US8MVn5qBtS5sKx7l+PFs9wfdsM3KHPyzSdjGnu4CDRZuDDZUNnHqApYUhfbYbIPWzWdLnVJ76bR4g13bYy+ZLfaKPKR9Sh5x29NW2T51qZ+r8kh0AVtvloVChl4dH9YE+28g6Pl3L6Rs7HNXOtXbcn5o7yjlqylziP4lxtlrQBj+OngTf0Wew+M8iJSropRpxsHl6rzG0Y3NStyY2QCKtWr7GeYCczYb9dgyBWQvpnv3UrdDp1UsZG3luXdrgWwAWwDGGmpgH9K2JNi1E6v1L59FkzYgvfVa7+MdcJwG4di30gJn6R8pfR3kkr/W1q8Clb3xsRCK8JBZ578lNWd3I9EnZ0kgjdq7l+FQhEXAFhLRvN+SlPtN+rr9LwAd4AUN9Bad9QBi/WjgEkEsAm77ymst4OJbCD196wM3nhKpTbMV2D45TD8y0OUou+I4yUzP8zMZsI6PAoG6AlFXAZIMmuqMO0Mv1DBcWVWHT0T+bs6Y2wmyjQq7bSCTtGWMFacqncmzPBVIAXOtTxhhqCswZH3UDGeYFvytsarv2PCCq9TlfAr+puviC39ggZa7rQy+6B/SMgzbt+mr9PsK14DvCLC3wsfeEByQ56qZlEbMxUsbC5qAP6gOQuhEWuDGrauxgq0KZSAPfsuHoDGBQL5u1wqAaYzy1r3qvdz4XfGgUDcmT8rDA5wCBMrTD1/iCX5TVB0366OX0hW+9cVLGvdjrtec+9uIz9tuHBXObOuTMfZsCdvqpa6Wtd7Tr1xk8muf621UgT+7ehuk2OFFhNvKSsc8F34lkcij8cKMK1xXgdYAnXp7e11vsW4NIiafzEgDs6/H91hNlzY2o7rdoD0dW4NDgS8gPlHqvBdzndWPOZqAugKM+/bWvVIDkKOBjQRL58fo1Z+xHXsD4zisac3fp1e/oY9T/dRU4NPhY7PluwSbnuiau58AK6PGNA7hl87CZAGC+fwHWOX1V+56rgAo8pwKHBh+wCpjIgVMS19wHatcSgCTCa+vWj7mC75qK3leB4yhwaPARkSVV8CWCCxRTZyoHkESMl1IPfESAtMUP8rxW0hdlHG0ZgO0lfE2bS/ncMfVsWKYCKvCvAq/kOKAiwCYgIE/EB5CI4oBOwHQJbIDm2mtsCz764wCyAW1s5Dqv4ZG2gjBl5iqgAtsrcGjwAZrAhXPgBezy2gqs+IUTEPHaWv8urEp9C/hqe86xFfBynWgw9bDdfoPMvTXyS1Gi917/jlEt1tNijXW7Vx+HBh8/RCSiAzoALrBDUBZ5UqLAXNecetegRL81KsQW0KUdUKWPCj7uUxbY4md+OKm2c+6rbpQwV4HHK/BKhsfberiF/NdBDLXgq2BKHXKixd63t0s/bgCy+pfu9N32DxQpe3S0V8fiuQqowHUFTgO+RH81qmrBl9fiVpZEW4CKSI3U/jkLEKxRIX0HfLQHhC340i9QrX619r1WARXYVoHTgC/f+Kp8icraV+BaJ+f8u1NeWYEabQElbQEeZRx5deUe10ANAPIazHVgmH5bYKbcXAVUYD8FTgG+QKuVsf6qOxXttW3WvgagRntrq2p/KnCfAqcA330SrN+aV15gB2zrDyLrW7LHOQrkkwMRef1cwRxRxv0k3hwo43Duosr5csH3gDkFfGycvaLMBwzp8F0yJ3x2qCmfMCr48mt8BWRt4/k5FBB855hHR3FFAcDHkcRnkDygKvg45/NEfuRKffNzKSD4zjWfjmZCgRZ8XAO59lWXqJBvxqZzKyD4zj2/ju4/Bfh2l4gP4OW8go9f5KlnOr8Cgu/8c+wI//sXwsCOnFddUsDHq62/wI+zVATfOHM99Ej5hRbgEe3VHy4CPiK99m8whxbs5IMXfCefYIf3rwIBXxvVAT7utb/4qtu5FRB8555fR/efAsANyNVoj1uUceTVV8HGUEDwjTHPw48y4Gv/iwbo+feW4y0PwTfenDtiFRheAcE3/BJQABUYTwHBN96cO2IVGF4BwTf8ElAAFRhPAcE33pw7YhUYXgHBN/wSUAAVGE8BwTfenDtiFRheAcE3/BJQABUYTwHBN96cO2IVGF4BwTf8ElAAFRhPAcE33pw7YhUYXgHBN/wSUAAVGE8BwTfenDtiFRheAcE3/BJQABUYTwHBN96cO2IVGF4BwTf8ElAAFRhPAcE33pw7YhUYXoF/APjKAFfpMCYAAAAAAElFTkSuQmCC\" width=\"318\" height=\"162\"\u003e\u003cbr\u003e\u003c/p\u003e\n\u003cp\u003eRa = 40 seconds blank hydrometer reading.\u003c/p\u003e\n\u003cp\u003eRb = 2 hours blank hydrometer reading.\u003c/p\u003e\n\u003cp\u003eRc = 40 seconds correction factor (temp \u0026gt;20\u0026ordm;C x 0.360)\u003c/p\u003e\n\u003cp\u003eRd = 2 hours correction factor (temp\u0026gt;20\u0026ordm;C x 0.360)\u003c/p\u003e\n\u003cp\u003eW = weight of soil.\u003c/p\u003e\n\u003cp\u003e%Sand + %Silt + %Clay = 100\u003c/p\u003e\n\u003cp\u003eSheldrick and Wang 1993\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eExtraction of PCBs in soil samples\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e10 g aliquot of well mixed soil sample was weighed into a solvent rinsed 200 ml beaker, the sample was spiked with 50 ml of 50:50 solvent mix of acetone and dichloromethane in 500 ml volumetric flask transferred to a sonicator for 20 minutes at 40 \u003csup\u003e0\u003c/sup\u003eC. The extract was filtered into a well labelled clean 100 ml round bottom flask using Whatman No. 41 filter paper. The process was repeated with an additional 50 ml solvent mix and filtered. The extract was concentrated to 2 ml with the aid of a rotary evaporator and the solvent was interchanged with n-Hexane and re-concentrated to 2 ml using gentle stream of Nitrogen gas. The sample extract was transferred to a 2 ml sample vials using a graduated pipette, ready for clean-up. Standard operating procedure was in accordance to Aziza \u003cem\u003eet al.,\u0026nbsp;\u003c/em\u003e(2021) with little modification.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCleanup of soil sample extracts\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe concentrated extract was subjected to purification in a 100-200mesh multi-layer silica gel (which had earlier been activated at 130 \u003csup\u003eo\u003c/sup\u003eC in the oven for 16 hrs, cooled in a desiccator before packing the polypropylene cartridge for analysis) and alumina column consisting of 2 g of anhydrous Na\u003csub\u003e2\u003c/sub\u003eSO\u003csub\u003e4\u003c/sub\u003e, 4 g of alumina and 3 g of silica gel packed from top to bottom. The 50 ml polypropylene cartridge was mounted on the retort stand and the base was plug with sterile cotton wool. The cartridge was conditioned with 10 ml n-hexane, the eluate was collected as waste in a beaker. 1-2 ml of the sample extract was added to the head of the column using a narrow tip 2 ml graduated pipette. The column was eluted with 5 ml of n-hexane, the eluate was collected in a clean 100 ml flask. Before the column dried up, 40 ml of Hexane/Diethyl ether (50:50) was added to the head of the cartridge. This fraction was also collected and added to the 100 ml flask. The combined fraction was evaporated using rotary evaporator to 2 ml at 40\u003csup\u003eo\u003c/sup\u003eC. The extract was solvent exchanged into n-hexane by addition of 5 ml n-hexane. The extract volume was reduced to 2 ml using gentle stream of N\u003csub\u003e2\u003c/sub\u003e gas. This was transferred into a 2 ml GC Vials with screw cap, ready for GCMS analysis (Aziza \u003cem\u003eet al.,\u0026nbsp;\u003c/em\u003e2021, Hakanson 1980).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClean up of food sample extracts (Rice and vegetables)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe concentrated extract was subjected to purification in a 100-200 mesh multi-layer silica gel (which had earlier been activated at 130 \u003csup\u003eo\u003c/sup\u003eC in the oven for 16hrs, cooled in a desiccator before packing the polypropylene cartridge for analysis) and alumina column consisting of 2 g of anhydrous Na\u003csub\u003e2\u003c/sub\u003eSO\u003csub\u003e4\u003c/sub\u003e, 4 g of alumina and 3 g of silica gel packed from top to bottom. The 50 ml polypropylene cartridge was mounted on the retort stand and the base was plug with sterile cotton wool. The cartridge was conditioned with 10 ml n-hexane, the eluate was collected as waste in a beaker. 1-2 ml of the sample extract was added to the head of the column using a narrow tip 2 ml graduated pipette. The column was eluted with 5 ml of n-hexane, the eluate was collected in a clean 100 ml flask. Before the column dried up, 40 ml of Hexane/Diethyl ether (50:50) was added to the head of the cartridge. This fraction was also collected and added to the 100 ml flask. The combined fraction was evaporated using rotary evaporator to 2 ml at 40\u003csup\u003eo\u003c/sup\u003eC. The extract was solvent exchanged into n-hexane by addition of 5 ml n-hexane. The extract volume was reduced to 2 ml using gentle stream of N\u003csub\u003e2\u003c/sub\u003e gas. This was transferred into a 2 ml GC Vials with screw cap, ready for GCMS analysis (Olatunji 2019).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eGC-MS instrumentation and analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe analysis was carried out using a Hewlett Packard Model 5890 Series II plus gas chromatograph, which was equipped with a Hewlett Packard 5972 Mass Selective Detector (GC/MS). For the analysis, a HP-5 fused silica capillary column was utilized, with specifications including a length of 30 meters, an internal diameter of 0.25 mm, and a film thickness of 0.25 \u0026micro;m. This column was coated with a mixture of 5% phenyl and 95% methylpolysiloxane.\u003c/p\u003e\n\u003cp\u003eThe temperature program for the column oven was initiated at 120 \u0026deg;C with a holding time of 1 minute. It was then raised to 190 \u0026deg;C at a rate of 20 \u0026deg;C per minute, further increased to 230 \u0026deg;C at a rate of 5\u0026deg;C per minute, and finally elevated to 300 \u0026deg;C at a rate of 25\u0026deg;C per minute, with a holding time of 10 minutes. The injector and detector temperatures were maintained at 280 \u0026deg;C and 300 \u0026deg;C, respectively, throughout the analysis. Helium was employed as the carrier gas, maintaining a consistent flow rate of 0.8 ml per minute. The injection process was carried out in split-less mode. For mass spectrometry, the instrument operated in electron impact ionization (EI) positive-mode, utilizing automatic gain control. The storage window was configured to encompass the mass-to-charge ratio (m/z) range from 200 to 500, employing selected ion monitoring (SIM). During data acquisition, the scan time was set at 1.0 second, with four micro-scans performed each second. The quantification of the target compounds was achieved by monitoring the characteristic ions at m/z 258, 292, 326, 362, 396, and 430. These ions were selected considering the parent ions of the group of PCBs present in PCB congener mixture Calibration was performed by injections of standard solution of MIX 19 (PCB-1, 5, 18, 31, 52, 44, 66, 101, 87, 110, 151, 153, 141, 138, 187, 183, 170, 180, 206) at 6 calibration levels (0.05, 0.1, 0.25, 0.5, 1 and 2 \u0026micro;g ml\u003csup\u003e-1\u003c/sup\u003e). In the investigated PCBs, no peak areas were detected in the blank samples, and the limit of detection was established as the concentration at which a signal-to-noise ratio of 3 was achieved. (LOD = 0.1 \u0026micro;g kg-1). Linearity was investigated within the range between: 0.01\u0026ndash;1 \u0026micro;g ml-1 and the R\u003csup\u003e2\u0026nbsp;\u003c/sup\u003evalues were found to be between 0.992 and 0.999.\u003c/p\u003e"},{"header":"RESULTS AND DISCUSSIONS","content":"\u003cp\u003e\u003cstrong\u003ePhysicochemical Properties of soil\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe physicochemical properties of the floodplain soil samples are presented in Table 4.1. The pH levels of the soil samples ranged from 4.85 to 7.54 across all the sampling locations, indicating that the soils are mildly acidic. This acidity can have an impact on the potential leaching of contaminants from the soil, primarily due to the soil-water partition coefficient. These pH values align with previous research conducted on the Ala River floodplain, as reported in earlier studies by Fadojumiti \u003cem\u003eet al., (\u003c/em\u003e2017).\u003c/p\u003e\n\u003cp\u003eThe Total Organic Matter (TOM) content fell within the range of 6.04 to 14.77, with the highest value observed at site B-Ayedun. This finding confirms the presence of organic matter in the soil. PCBs, being hydrophobic chemicals with limited water solubility, tend to partition into the organic matter present in the soil. A noteworthy observation is the significant positive correlation observed between Total Organic Carbon (TOC) and the sum of PCBs (\u0026sum;PCBs), with a correlation coefficient (r) of 0.828. This suggests that organic matter plays a crucial role in both the contribution to and fate of PCBs in the River Ala floodplain.\u003c/p\u003e\n\u003cp\u003eThe percentage of sand, clay and silt in the soil profiles ranged between 78.56 to 91.29, 7.76 to 16.73 and 0.95 to 6.6 respectively and referred to as sand clay silt. The soil texture is predominantly sand as represented in Table 1.\u003c/p\u003e\n\u003cp\u003eTable:\u0026nbsp;Physico-chemical properties of soil\u003c/p\u003e\n\u003cp\u003e\u003cimg 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\" alt=\"image\" width=\"678\" height=\"418\"\u003e\u003c/p\u003e\n\u003cp\u003eKey: A-Aule, B-Ayedun, C-Barracks, D- Adebowale, E- Alagbaka, F- Fiwasaye, G- Okuta Elerinla, H \u0026ndash; St. Thomas, I \u0026ndash; Sijuwade\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDistribution pattern of PCBs in soil samples\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA summary of the PCB concentrations measured in floodplain soil is presented in Table 1.. The PCB concentrations for the 19 congeners examined in these soils ranged from 20 \u0026micro;g kg\u003csup\u003e-1\u003c/sup\u003e to 60 \u0026micro;g kg\u003csup\u003e-1\u003c/sup\u003e across all sampling locations. These findings align with the values reported in Abata 2017. It\u0026apos;s worth noting that while 19 PCB congeners were investigated in the samples, only 14 PCBs were identified in the soil. PCBs-1, 87, 151, 206, and 187 were not detected in the soil samples. The concentrations of PCBs in the floodplain soils exhibited significant variations compared to the concentrations of PCBs found in edible crops (rice and vegetables). The PCB homolog pattern in soils at different locations shows PCB 66 having the highest occurrence in Aule, Ayedun, Okuta Elerinla and Fiwasaye. Ayedun location B with the highest Organic matter content of 14.77 has ten PCBs present which are PCB 18, 31, 44, 52, 66, 87, 110, 138, 141, 153 and 170 at higher concentrations which could be as a result of affinity the hydrophobic organic pollutant PCBs to the soil. Tri and tetra homologues dominated in majority of the locations. Hexa PCBs 153 and 187 have highest concentrations of 60 \u0026micro;g kg\u003csup\u003e-1\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDistribution pattern of PCBs in rice samples\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePCB congeners were analyzed in flood plain vegetables of Ala River and their observed concentrations are presented in Fig. 2. The mean concentration ranged between N.D \u0026ndash; 60 \u0026micro;g kg\u003csup\u003e\u0026minus;1\u003c/sup\u003e. In all the samples, nine (9) PCBs were not detected in vegetable samples. Only ten (10) were discovered. PCB patterns when characterized in terms of individual homolog, The PCB homolog pattern in vegetables at different locations has hexa PCBs as the major contributors and accounted for 58% to total PCBs and the contribution of remaining homolog is about 42%. The sum of all PCBs ranged in the interval 34.2 \u0026ndash; 48.5 \u0026micro;g kg\u003csup\u003e-1\u003c/sup\u003e. Site B Ayedun has the highest prevalent with 8PCBs investigated.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConcentration of PCBS in rice samples\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA summary of the concentrations of PCBs sampled in rice is represented in Fig. 3. The PCBs concentration for the 19 congeners investigated in the rice sample ranged from not detected (ND) to 60 \u0026micro;g kg\u003csup\u003e-1\u003c/sup\u003e for all sampling locations with six PCBs not detected. The concentration of PCBs in the rice is higher than concentration in soil which may result from plant uptake of PCBs into tissues and cells of plant which suggests its bioaccumulation potential. Homologue patterns of PCB as presented in figure 4.3 shows di - tetra PCBs as the major contributors and accounted for 62.42% to total PCBs and the contribution of remaining homolog is about 37.58%. Location Adebowale has the highest prevalent with seven (7) PCBs, Barracks has seven (7) PCBs present. PCB-126 concentration was below detection limit at all the locations, thus higher homologue PCB183 has the highest concentration.\u003c/p\u003e"},{"header":"CONCLUSION","content":"\u003cp\u003eFinally, this study established the environmental assessment and contamination of PCBs in floodplain soils and edible crops of Ala River, South-West Nigeria. It also revealed that the levels of PCBs falls within the acceptable limit standards for soil and edible crops. Dioxin like indicator PCBs were not discovered in the samples. . Consequently from the above findings, it was deducted that concerted effort needs to be made by the relevant authorities to reduce the levels so it doesn\u0026rsquo;t pose health risks to individuals and aquatic habitats.\u003c/p\u003e"},{"header":"REFERENCES","content":"\u003col\u003e\n\u003cli\u003eAbata E., (2018)Levels and Seasonal Variations of Polychlorinated Biphenyls (PCBs) in Sediment of Alariver, Ondo State, Nigeria. \u003cem\u003eChemical Science International Journal\u003c/em\u003e\u003cstrong\u003e\u003cem\u003e \u003c/em\u003e\u003c/strong\u003e21(3):1-7\u003c/li\u003e\n\u003cli\u003eAyeni A. O., Balogun, I. I. \u0026amp; Soneye, A. S. (2011)Seasonal assessment of physico-chemical concentration of polluted urban river: a case of Ala River in Southwestern-Nigeria\u0026rdquo;, Research Journal of Environmental Sciences, 5, 22\u0026ndash;35\u003c/li\u003e\n\u003cli\u003eAziza, A.E., Iwegbue, C. M. A., Tesi, G. O., Nwajei, G. E., \u0026amp; Martincigh, B. S. (2021). Concentrations, sources, and exposure risk of polychlorinated biphenyls in soil profiles of the floodplain of the lower reaches of the River Niger, Nigeria. \u003cem\u003eEnviron Monit Assess,\u003c/em\u003e 193:579 https://doi.org/10.1007/s10661-021-9310-9\u003c/li\u003e\n\u003cli\u003eFadojutimi P.O. , Aiyesanmi F.A , Adelaja O.A \u0026amp; Oladele S.G (2017) Assessment of Heavy Metal Enrichment and Level of Contamination of Floodplains Soil in Ondo State, Nigeria \u003cem\u003eJournal of Geography, Environment and Earth Science International\u003c/em\u003e 10(2): 1-11, 2017; Article no.JGEESI.32278 ISSN: 2454-7352\u003c/li\u003e\n\u003cli\u003eGrittini, C., Malcomson, M., Fernando., Q. \u0026amp; Korte, N., Rapid Dechlorination of Polychlorinated Biphenyls on the Surface of a Pd/Fe Bimetallic System. \u003cem\u003eEnviron. Sci. 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(2020a) Spatial characteristics and risk assessment of polychlorinated biphenyls in surficial sediments around crude oil production facilities in the Escravos River Basin, Niger Delta, Nigeria. \u003cem\u003eMarine Pollution Bulletin 159\u003c/em\u003e (2020) 111462\u003cu\u003e. \u003c/u\u003ehttps://doi.org/10.1016/j.marpolbul.2020.111462\u003c/li\u003e\n\u003cli\u003eIwegbue, C. M. A., Tesi, G. O., Overah, L. C., Emoyan, O. O., Nwajei, G. E., \u0026amp; Martincigh, B. S. (2020b). Efects of fooding on the sources, spatiotemporal characteristics and human health risks of polycyclic aromatic hydrocarbons in foodplain soils of the lower parts of the River Niger. Nigeria. \u003cem\u003ePolycyclic Aromatic Compounds\u003c/em\u003e, 40(2), 228\u0026ndash;244.\u003c/li\u003e\n\u003cli\u003eKakareka S, Kukharchyk T, \u0026amp; Brevik K (2015). Sources of Polychlorinated biphenyls emissions. EMP/CORNAIR Guide book\u003c/li\u003e\n\u003cli\u003eMaliszewska-Kordybach, B., Smreczak, B., \u0026amp; Klimkowicz-Pawlas, A. (2013).The levels and composition of persistent organic pollutants in alluvial agriculture soils affected byfooding. \u003cem\u003eEnvironmental Monitoring Assessment\u003c/em\u003e, 185(12), 9935\u0026ndash;9948.https://doi.org/10.1007/s10661-013-3303-3\u003c/li\u003e\n\u003cli\u003eNouira, T., Risso, C., Lassaad, C., Budzinski, H., \u0026amp; Boussetta, H., (2013). Polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in surface sediments from Monastir Bay (Tunisia, Central Mediterranean): occurrence, distribution and seasonal variations. \u003cem\u003eChemosphere\u003c/em\u003e 93, 487\u0026ndash;493.\u003c/li\u003e\n\u003cli\u003eOlatunde Olatunji (2019) Evaluation of selected polychlorinated biphenyls (PCBs) congeners and dichlorodiphenyltrichloroethane (DDT) in fresh root and leafy vegetables using GCMS. \u003cem\u003eScientific reports 9\u003c/em\u003e(1) doi:10.1038/s4198-018-36998-8\u003c/li\u003e\n\u003cli\u003eOlolade I.A., Arogunrerin I.A., Oladoja N.A., Ololade O.O., \u0026amp; Alabi A.B. (2021).Concentrations and Toxic Equivalency of Polycyclic Aromatic Hydrocarbons (PAHs) and Polychlorinated Biphenyl (PCB) Congeners in Groundwater Around Waste Dumpsites in South‑West Nigeria. \u003cem\u003eArchives of Environmental Contamination and Toxicology\u003c/em\u003e (2021) 80:134\u0026ndash;143 https://doi.org/10.1007/s00244-020-00790-3\u003c/li\u003e\n\u003cli\u003eSchulte EE. (1995) Recommended soil organic matter tests. In Recommended soil testing procedures for the North-eastern United States. 2nd edition. Chapter 8\u003c/li\u003e\n\u003cli\u003eSchwartz R, Gerth J., Neumann-Hensel H., \u0026amp; Forstner U. (2006) Assessment of highly polluted fluvisol in the spittelwasser floodplain based on national guideline values and MNA criteria . Journal of soils and sediments 6 (3): 145-155 doi:10.1065/jss2006.06.166\u003c/li\u003e\n\u003cli\u003eSheldrick B.H, \u0026amp; Wang C. (1993)Particle size distribution. In Carter M R (ed.), Soil Sampling and Methods of Analysis for Canadian Society of Soil Science, Lewis Publishers, London; 1993:449-511.\u003c/li\u003e\n\u003cli\u003eTakasuga, T., Senthilkumar, K., Matsumura, T., Shiozaki, K., \u0026amp; Sakai, S. (2006). Isotope dilution analysis of polychlorinated biphenyl (PCBs) in transformer oil and global commercial PCB formulations by high resolution gas chromatography-high resolution mass spectrometry. \u003cem\u003eChemosphere\u003c/em\u003e, 62, 469\u0026ndash;484Iwegbue \u003cem\u003eet al., \u003c/em\u003e2020a\u003c/li\u003e\n\u003cli\u003eThonon, I. (2006). Deposition of sediments and associated heavy metals on foodplains. Netherlands Geographical Studies 337. \u003cem\u003eKoninklijk Nederlands Aardrijkskundig Genoostschap, Faculteit Geowetenschappen\u003c/em\u003e Universiteit Utrecht\u003c/li\u003e\n\u003cli\u003eUnyimadu, J.P., (2017). Evaluation of contamination of River Niger by persistent organic pollutants (POPs) using sediment quality guidelines (SQGs). \u003cem\u003eJ. Coast. Zone Manag\u003c/em\u003e. 20 (2(Suppl)). https://doi.org/10.4172/2473-3350-C1-003\u003c/li\u003e\n\u003cli\u003eWalkley, A., \u0026amp; Black, I.A., 1934. An examination of the Degtjareff method for determining soil organic matter and a proposed modification of the chromic acid titration method. \u003cem\u003eSoil Sci\u003c/em\u003e. 37, 29\u0026ndash;38.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"No funding from external bodies","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Poly chlorinated biphenyls PCBs, floodplain, edible crops","lastPublishedDoi":"10.21203/rs.3.rs-4061550/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4061550/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eFlooding is one significant process that contributes to the movement of soil and sediments with the pollutants present in it along the river bank. With higher velocities of water, flooding can take contamination downstream. The soil, edible crops (rice and vegetables) samples were collected from Ala river floodplain in Ondo State and analyzed for their physico-chemical characteristics and level of Polychlorinated biphenyls present. The concentrations of nineteen (19) polychlorinated biphenyls (PCBs) were analyzed in soils collected at nine different sites along the floodplain and edible crops collected from six of the sites/ location using Gas Chromatography Mass Spectrometer (GC-MS) to determine the level of contamination of the floodplain and potential risks to the ecosystem and humans. The Ʃ-19 PCB concentrations in the floodplain soils varied between not detected (nd) -60 µg kg \u003csup\u003e−1\u003c/sup\u003e, n.d – 60 µg kg \u003csup\u003e−1\u003c/sup\u003e in vegetables and not detected to 80 µg kg \u003csup\u003e−1\u003c/sup\u003e in rice across different locations. Higher concentration values were recorded in rice which suggests plants uptake and bioaccumulation potentials.The concentration of di to tetra homologues are more predominant in the samples. The concentration is lower than the value of permissible limit 2mg kg\u003csup\u003e-1\u003c/sup\u003e recommended by Canadian Soil Quality Guideline (CSQG) and United States Environmental Protection Agency (US EPA). Dioxin-like PCBs were not detected\u003c/p\u003e","manuscriptTitle":"Assessment Of Level Of Polychlorinated Biphenyls (PCBs) In Soil And Edible Crops From River Ala Floodplain In Akure","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-03-11 11:54:29","doi":"10.21203/rs.3.rs-4061550/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"79186455-6976-4f88-9709-02601d11c8f6","owner":[],"postedDate":"March 11th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":29268414,"name":"Environmental Chemistry"}],"tags":[],"updatedAt":"2024-03-11T11:54:29+00:00","versionOfRecord":[],"versionCreatedAt":"2024-03-11 11:54:29","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4061550","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4061550","identity":"rs-4061550","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}