Outdoor formaldehyde and NO2 exposures and markers of genotoxicity in children living near chipboard industries

Background: Industrial air pollution is a public health hazard. Previous evidence documented increased respiratory symptoms and hospitalizations in children who live near the factories in the largest chipboard manufacturing district in Italy (Viadana). Objectives: We evaluated the association of outdoor exposure to formaldehyde and nitrogen dioxide (NO2) with markers of early genotoxic damage in oral mucosa cells of randomly selected children (6-12 years of age) living in Viadana. Methods: In 2010-2011, DNA strand breaks and nuclear abnormalities were evaluated in exfoliated buccal cells by the comet and micronucleus assays, respectively, and formaldehyde and NO2 were monitored by passive sampling. Annual exposure estimates to pollutants were assigned to children's houses by spatial interpolation. Results: Of 656 children, 413 (63%) participated. Children living near (< 2 km) the chipboard industries had the highest average exposure to formaldehyde and NO2 (p < 0.001). A 1-SD increase in formaldehyde (0.20 mu g/m(3)) was associated with a 0.13% (95% CI: 0.03, 0.22%) higher comet tail intensity, a 0.007 (95% CI: 0.001, 0.012) higher tail moment, and a 12% relative increase [relative risk (RR) = 1.12; 95% CI: 1.02, 1.23] in nuclear buds. A 1-SD NO2 increase (2.13 mu g/m(3)) was associated with a 0.13% (95% CI: 0.07, 0.19%) increase in binucleated cells and a 16% relative increase (RR = 1.16; 95% CI: 1.06, 1.26) in nuclear buds. Conclusions: Exposure to pollutants was associated with markers of genotoxicity in exfoliated buccal cells of children living in a region with chipboard industries. These findings, combined with previously reported associations between chipboard industrial activities and respiratory outcomes in children, add to concerns about potential adverse effects of industry-related exposures in the Viadana district