Research Article: DDT, Dioxins, and PCBs in Sediments in a Historically Polluted Estuary along the Gulf of Mexico

Abstract

This study assessed current profiles of organochlorine pollutants in sediment of Escambia Bay and River in northwest Florida, United States (US), which experienced catastrophic environmental collapse in the 1970s as a result of unregulated industrial and domestic sewage releases. Fifty-seven composite sediment samples were collected with a ponar grab sampler. Organochlorines were extracted with United States Environmental Protection Agency (USEPA) Method 3550 and concentrations were determined with USEPA Method 1668A for polychlorinated biphenyls (PCBs), USEPA Method1613B for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and USEPA Method 8081A for 4,4′-dichlorodiphenyltrichloroethane (DDT), 4,4′-Dichlorodiphenyldichloroethane (DDD), and 4,4′-Dichlorodiphenyldichloroethylene (DDE). For PCBs, 12 (21%) out of the 57 samples exceed the Florida threshold effects level (TEL) of 21.6 μg/kg and no sample exceeds the Florida probable effects level (PEL) of 189 μg/kg. The 17 PCDD/F congeners that a...