Linear alkylbenzenes in riverine runoff of the Pearl River Delta (China) and their application as anthropogenic molecular markers in coastal environments

The average concentrations of Sigma LABs (Sum of C-10 - C-13-LABs) in runoff samples collected from the eight major riverine outlets of the Pearl River Delta (PRD) of China ranged from 1.4 to 6124 ng/L in the dissolved phase and from 0.01 to 11.4 mu g/g dry weight in the particulate phase during March 2005 - February 2006. The annual riverine flux of Sigma LABs from the PRD to the coastal ocean was estimated at approximately 14 tons/yr. The inventories of Sigma LABs in agricultural lands of Guangdong Province ranged from 313 to 1825 kg/yr. The early and late rice fields were the major sink of LABS, accounting for approximately 68% of total LABS inventory in agricultural lands. The social-economically estimated annual discharge of LABS from household detergents in the PRD was similar to 696 tons/yr, more than an order of magnitude higher than that estimated from field measurements (about 14 tons/yr), which was attributed to several factors. (C) 2007 Elsevier Ltd. All rights reserved.