Levels and characteristics of polychlorinated biphenyls in surface sediments of the Chaobai river, a source of drinking water for Beijing, China.

ABSTRACT

We collected surface sediments from the Chaobai river, the dominant source of drinking water for Beijing, China, to assess the status of contamination by polychlorinated biphenyls and evaluate their sources. Total concentrations of polychlorinated biphenyls in the sediments ranged from 0.125 to 70.6 ng/g dry weight and correlated with the locations relating to painting operation such as printing factories and construction material markets. Dioxin-like polychlorinated biphenyls were present and corresponded with constituents of commercial polychlorinated biphenyl mixtures. Principal component analysis indicated two dominant sources of polychlorinated biphenyls in the sediments-deposition from airborne emissions and point-source pollution from factories. An ecological risk assessment concluded that there was only slight polychlorinated biphenyl pollution in the sediments of the Chaobai river, which was not likely to induce adverse biological effects. Our findings provide information for polychlorinated biphenyl risk assessment and recognition of the dominant sources of these compounds in drinking water in China.