INAA for the determination of extractable organohalogens in precipitation in Shanghai, China

The paper presents the results of determination of extractable organohalogens (EOX) by instrumental neutron activation analysis (INAA), and polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) by gas chromatography (GC), in atmospheric precipitation in Shanghai, China, from January to August 2005. The results showed that EOCI was the major component of organohalogens in precipitation. A significant correlation between the concentrations of EOBr and EOI was observed (r(2) = 0.75), which suggested that EOBr and EOI in precipitation might mainly come from the same sources. There were no clear seasonal trends for the concentrations of EOX. The concentrations of Sigma PCBs ranged from 0.2-2.8 ng/l, with the dominant PCBs containing 3 to 5 chlorine atoms. HCH was the predominant pesticide in precipitation, accounting for over 80% of total OCPs, in which beta-HCH took 28%-72% of total HCH. Also, there may be an evidence for significantly historical usage of DDT.