Organochlorine compounds in the marine atmosphere of Singapore

Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were quantified in high-volume air samples collected on polyurethane foam (PUF) over the sea surface of Singapore during the summer monsoon period of 2004. A novel and quality assured microwave-assisted extraction (MAE) procedure for PUF was developed as an alternative to conventional Soxhlet extraction for the analysis of organochlorine compounds (OCs). Average concentrations of ΣPCBs, ΣHCHs and ΣDDTs in air samples were 32, 311 and 8 pg m-3, respectively. Overall, a decline in the ocean atmospheric concentration of DDTs was noted relative to data obtained from the early 1990s, but current data are in a similar range for HCH and PCBs. Levels of OCs in the equatorial atmosphere were compared to equivalent data from temperate regions available in the literature. On a global scale, the levels of DDTs and PCBs in the atmosphere of Singapore are low, but moderate for HCHs.