Occurrence, Spatial Distribution, and Bioaccumulation of Dissolved Synthetic Musks in Freshwaters across China

Commercial
chemicals, such as synthetic musks, are of global concern,
but data on their occurrence and spatial distribution in aquatic environments
of large scale are scarce. Two sampling campaigns were conducted in
the present study to measure freely dissolved synthetic musks in freshwaters
across China using passive samplers, along with biological coexposure
at selected sites. Polycyclic musks (PCMs) dominated synthetic musks,
with a detection frequency of 95%. Higher concentrations of PCMs were
observed in densely populated Mid, East, and South China compared
to less populated regions, indicating the significance of anthropogenic
activities for synthetic musks in water. The concentration ratios
of galaxolide (HHCB)/tonalide (AHTN) were significantly higher in
low-latitude areas than in high-latitude areas from June to September,
suggesting that solar radiation played an important role in the degradation
of HHCB/AHTN. Significant correlations were found between dissolved
concentrations of HHCB and AHTN and their lipid-normalized concentrations
in coexposed fish and clam. The estimated hazard quotients for HHCB
and AHTN in freshwater fish consumed by humans were less than 0.01
at all sampling sites except the Yangtze River Basin. These results
help to understand the environmental fate and ecological risks of
synthetic musks on a large geographical scale.