Environmental levels of PBDEs in Brazilian industrial cities: Sources, seasonal variability, and human exposure implications.

Abstract

Polybrominated diphenyl ethers (PBDEs) are prioritised chemicals regulated under the Stockholm Convention on Persistent Organic Pollutants. PBDE data are, however, developing for outdoor air, soil, surface water and sediment in Brazil. This study therefore targeted eight commonly reported PBDE congeners in air (using passive air sampler-polyurethane foam) and soil in Sorocaba (a major industrial city) as well as adjacent cities (Votorantim and Itu) in Brazil. Additional surface water and sediment samples were collected from Itupararanga reservoir, a major dam for domestic water supply. All samples were collected at approximately two-month intervals for a total period of one year. The average air, soil and sediment concentrations were observed at 310 pg/m³, 14 ng/g, dw, and 2.5 ng/g, dw, respectively. The air concentrations compare well with the top range of other global data while soil/sediment is consistent with the low range of the global data. No PBDE congener was detected in the surface water samples. The estimated soil inventory of the ∑₈PBDEs and PBDE-209 in the soil were evaluated at 1.3 ± 0.17 and 1.2 ± 0.15 metric tons, respectively. The temporal air concentration pattern was consistent with a possible influence of wet scavenging, although the association was not statistically significant when all six sampling periods were considered. The potential impact of the wet scavenging was not observed in the soil concentrations. Human exposure risk was generally low for both soil (dermal plus accidental ingestion) and air (dermal plus inhalation ingestion) samples, with risk from air dominating that of soil under normal exposure. Relevant recommendations are provided for future scientific work regarding changes and potential factors influencing PBDE congener patterns.