Polychlorinated biphenyls in the Nanshan Underground River, China.

Karst areas have much higher ecological vulnerability and are easy to be contaminated by polychlorinated biphenyls (PCBs) which are introduced as health risk pollutants. PCBs concentrations were used to understand the transport behavior of PCBs conducted in the karst Nanshan Underground River, China. Water and sediments from the underground river water, and sediments and soil from the surface of the corresponding watershed were collected monthly in 2011 and 2012 and PCBs were analyzed. Seasonal variations were found in concentrations of PCBs both in the waters and sediments. PCBs concentrations varied from 0.3 to 29.9 ng·L in the groundwater, while from 0.1 to 366.1 ng·g in the underground sediments. Correlations were found in concentrations of PCBs in waters and sediments between the underground river and surface systems which indicate that the surface systems play a major role for the transport of PCBs and contamination in the underground river systems. Karst features are liable for the transport behavior. The underground river waters transport PCBs at mean 3 g·day. [ABSTRACT FROM AUTHOR]