Survey of organochlorine pesticides in the atmosphere and soil of two typical landforms of Southern Anhui Province, China: Sources and air-soil exchange

Organochlorine pesticides (OCPs) were detected in the atmosphere and soil of Southern Anhui, China. The average concentration of ∑OCPs in the atmosphere along the Yangtze River (YR) was 950 ± 400 pg m−3, and was higher than that in the Huangshan Mountain (HM) which was 560 ± 120 pg m−3. The average concentration of ∑OCPs in the soil along the YR was 4.4 ± 1.9 ng g−1, and was lower than that in the HM which was 8.3 ± 2.3 ng g−1. Fugacity fraction (ff) values of DDTs, endosulfan I, and γ-HCH found in Southern Anhui were <0.3, suggesting obvious net gaseous deposition. For HCB, almost all the sites in Southern Anhui had ff > 0.7, suggesting obvious volatilization. For α-HCH, sites in the HM showed obvious net volatilization, and both volatilization and deposition of α-HCH could occur along the YR. The α/γ-HCH values in the atmosphere were lower than that in the technical HCH mixtures, probably indicating the inputs of lindane. Patterns of DDT congeners indicated that atmosphere of Southern Anhui was largely influenced by external fresh input of technical DDT. In the HM, atmospheric endosulfan I, p,p′-DDT and o,p′-DDT mainly came from other source regions by the atmospheric transportation, while both local soil re-emission and external input would have influence on the atmospheric α-HCH. For atmospheric HCB in the HM, re-emission from local soil might be the primary source. Air back trajectories analysis showed high levels of OCPs found along the YR might attributed to the atmospheric transport from the lower reach of the Yangtze River basin.