Lichen, moss and soil in resolving the occurrence of semi-volatile organic compounds on the southeastern Tibetan Plateau, China

Abstract

This study investigated a wide range of semi-volatile organic compounds (SVOCs), including 28 persistent organochlorine pesticides (OCPs), 18 polychlorinated biphenyls (PCBs), 13 polybrominated diphenyl ethers (PBDEs), and 3 hexabromocyclododecane (HBCD) congeners in lichen, moss and soil collected from the southeastern Tibetan Plateau, China. This allows research provides insight into elevation gradient distributions and possible cold trapping effects of SVOCs in this high mountain area, and compares lichens and mosses as air passive samplers for indicating SVOC occurrences. DDTs, endosulfans, HCHs and hexachlorobenzene predominated in all of the samples. Source analysis indicted that there were fresh inputs of DDTs and HCHs in the sampling region. Lichens and mosses shared commonalities in revealing the profiles and levels of SVOCs based on their lipid-content-normalized concentrations. The concentrations of 12 OCPs and 14 PCBs in lichens were significantly linearly correlated with altitudes, whereas the correlations for mosses and soil with altitudes were insignificant. Both a frequency distribution diagram and the Mountain Contamination Potential Model indicated that SVOCs with specific values of log KOA (8–11) and log KWA (2–4) had relative high mountain contamination potential on the Tibetan Plateau.