Spatial variability of nitrogen dioxide and formaldehyde and residential exposure of children in the industrial area of Viadana, Northern Italy

ABSTRACT Chipboard production is a source of ambient air pollution. We assessed the spatial variability of outdoor pollutants and residential exposure of children living in proximity to the largest industry for chipboard production in Italy, aiming at evaluating the reliability of exposure estimates obtained from passive sampling for an ongoing epidemiological study. We obtained data on NO 2 and formaldehyde, collected by the environmental protection agency of Lombardia region, at 25 passive sampling sites in the municipality of Viadana during 10 weeks (2017-18), and compared NO 2 measurements with average weekly concentrations from continuous monitors. We compared interpolated surfaces of NO 2 and formaldehyde for 2017-18 with previous maps for 2010. We assessed the relationship between residential proximity to the industry and pollutant exposures, assigned both using our maps and available countrywide/continental models based on routine monitoring data on NO 2 , PM 10 , and PM 2.5 . The correlation between weekly NO 2 concentrations from a continuous monitor and a co-located passive sampler was high (Pearson’s r = 0.89), although passive sampling underestimated NO 2 during the cold season. For both 2010 and 2017-18, we observed higher NO 2 and formaldehyde concentrations in the southern part of Viadana, with hot-spots in proximity to the industry. PM 10 and PM 2.5 exposures were higher for children at 3.5 km. The density of roads and population was also higher in proximity to the industry. Findings: from a variety of exposure models suggest that children living in proximity to the chipboard industry in Viadana are more exposed to air pollution and that exposure gradients are relatively stable over time.