Air monitoring of organochlorine pesticides (OCPs) in Bursa Trkiye: Levels, temporal trends and risk assessment

Monitoring concentration levels of persistent organic pollutants (POPs) is required to evaluate the effectiveness of international regulations to minimize the emissions of persistent organic pollutants (POPs) into the environment. In this manner, we evaluated the spatial and temporal variations of 22 organochlorine pesticides (OCPs) using polyurethane foam passive air samplers at ten stations in Bursa in 2017 and 2018. The highest concentration value for sigma 22OCPs was detected in Agako center dot y (775 pg/m3) and Demirtas, (678 pg/m3) sampling sites, while the lowest value was observed in Uludag University Campus (UUC, 284 pg/m3) site. HCB, gamma-HCH, Endo I, and Mirex were the most frequently detected OCPs, which shows their persistence. Diagnostic ratios of beta- /(alpha + gamma)-HCH have pointed to historical and possible illegal OCP usage in the study area. The seasonality of air con-centrations (with spring and summer concentrations higher than winter and autumn concentrations) was well exhibited by alpha-HCH, beta-HCH, gamma-HCH, HCB, Endo I, and Mirex but not aldrin, dieldrin, and alpha-chlordane (CC). Levels of OCPs detected in ambient air in the current study were relatively similar to or lower than those reported in previous studies conducted in Turkiye. Back trajectory analysis was applied to identify the possible sources of OCPs detected in the sampling regions. The Clausius-Clapeyron approach was used to investigate the temperature dependence of OCP gas-phase atmospheric concentrations. The data showed that long-range atmospheric transport affects ambient air OCP concentrations in the study area.