Assessing the occurrence and sources of synthetic additive pollutants in lake sediments using fecal and sewage markers

Benzotriazole ultraviolet stabilizers (BZT-UVs), substituted diphenylamine antioxidants (S-DPAs), and synthetic phenolic antioxidants (SPAs) are three types of synthetic additive pollutants that are received increasing attention in the recent decade. In this study, a total of twenty-seven target analytes were measured in sediment cores and surface sediments collected from a lake with long sedimentary history. All target analytes were detected in the sediment samples, and mean values of the total ∑BZT-UVs, ∑S-DPAs and ∑SPAs concentrations were 220 ± 552 ng/g dry weight (d.w.), 20.8 ± 27.9 ng/g d. w., and 95.8 ± 146 ng/g d. w., respectively. Based on the dating results of two sediment cores, the total concentrations of BZT-UVs, S-DPA, and SPAs showed a fluctuating but overall increasing trend over time, which intuitively reflects the change of historical emissions. Meanwhile, fecal and sewage markers (i.e., sterols and pharmaceuticals, respectively) were jointly used to trace the probable sources of these pollutants. Results from the correlation and clustering analyses suggest that unregular fecal discharges and point-source domestic sewage need to be considered if pollution in the investigated area is to be controlled. To our knowledge, this study is the initial attempt to reveal the temporal variations of these synthetic additive pollutants in an aquatic environment in China and to demonstrate the feasibility of using markers to trace the sources of emerging pollutant analogues.