Air Monitoring of Polychlorinated Biphenyls and Organochlorine Pesticides in Eastern Siberia: Levels, Temporal Trends, and Risk Assessment

In this study, we evaluate the long-term and seasonal variations of polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), α-, γ-hexachlorocyclohexanes (HCH), and p,p′-dichlorodiphenyltrichloroethane (p,p′-DDT) and its metabolites through a passive air sampling method at two (urban and suburban) stations in Eastern Siberia, Russia, in 2011–2017. The median levels of HCB, ∑HCHs, ∑DDTs, ∑PCB39, and ∑PCB6 in the air were 116, 84, 55, 128, and 41 pg/m3 and 83, 21, 11, 52, and 16 pg/m3 at the urban and suburban stations, respectively. PCB and HCH levels in the air of Irkutsk decreased considerably in the 2000s, in comparison to the late 1980s and early 1990s, while an increasing trend was observed for HCB during the 2010s. The seasonality of air concentrations (with summer concentrations higher than winter concentrations) was well exhibited by PCB, HCH, and DDT, but not HCB. Significant correlations were observed between approximately all studied persistent organic pollutants and the average air temperature, quantity of precipitation, and frequency of the prevailing wind direction during the sampling period. The daily doses of PCBs, DDTs, HCHs, and HCB under human exposure by inhalation amounted to 38, 21, 27, and 35 and 17, 6, 7, and 27 pg/kg body weight per day in urban and suburban areas, respectively.