Legacy organochlorines in estuarine sediment in relation to socioeconomic pattern in multi-coastal watersheds

Estuarine sediment quality is highly associated with anthropogenic activities in watersheds. This study attempts to couple socioeconomic patterns with estuarine sediment quality via legacy organochlorines in 14 Chinese coastal watersheds. Sedimentary concentrations of HCHs, DDTs, and PCBs showed a significant spatiality in estuary, up to 48.7 +/- 15.1, 89.0 +/- 46.4, and 54.5 +/- 17.2 ng g(-1), which were predominated by beta-HCH, p,p '-DTs, and tri- to penta-PCBs, respectively. Ecological risk of organochlorines was negligible except few moderate risks for DDTs and PCBs against the first class quality of the marine sediment quality guidelines of China. Sedimentary DDT and PCB concentrations were significantly delineated by an environmental Kuznets curve model as a function of non-agricultural GDP per capita in watersheds, while HCHs by an increasing linear model. Findings of this study provide a tool to quantify the contribution of anthropogenic development in watershed to environmental change in estuary across the world.

Automated summary

This study found that the concentration of organochlorines in estuarine sediment is influenced by human activities in the watersheds, especially with higher risks of DDTs and PCBs. Furthermore, there is a significant correlation between non-agricultural GDP per capita and sedimentary concentrations of DDT and PCB, providing a tool for researchers to quantify the impact of human development in watersheds on environmental changes.