Program

General Session 4: Marine environment, ecosystem & sustainability

1010

Spatial and temporal trends of DDT and PCBs in marine sediment at a superfund site
Monday 9th @ 1010-1035
Room 1
Jay Gan* , University of California Riverside
Fang Jia, University of California Riverside
Allison Taylor, University of California Riverside
Chunyang Liao, University of California Riverside
Kunde Lin, University of California Riverside
Presenter Email: jgan@ucr.edu

Coastal lines next to major metropolises are often hot spots of contamination by persistent organic pollutants (POPs). The Palos Verde Shelf Superfund site in the Pacific Ocean, off the coast of Los Angeles, is one of such sites. Discharge of municipal wastewater effluents over the last century has resulted in the accumulation of a thick layer of organic matter-rich sediment on the ocean floor, while the release of industry wastewater from a DDT manufacturing facility during the 1950-1970s led to the deposition of large amounts of DDT and PCBs in the marine sediment. Consequently, there is a large swath of ocean floor, measuring in many square kilometers, that is contaminated with DDT and PCBs, with the highest level of DDT derivatives at 20,000 ppm. The Palos Verde Shelf (PVS) contaminated area is listed as a Superfund site, as DDT and PCBs are at levels posing potential risks to local residents through seafood dietary exposure. The PVS site has a water depth >60 m, rendering any remediation effort a great challenge. The U.S. EPA has reverted to monitored natural attenuation as a means for remediation. In this presentation, we will provide an overview of the spatial distribution patterns of DDT and PCBs at the PVS site, historical trends in sedimentation and accumulation of DDT and PCBs, and in situ transformations. Biomonitoring of benthic and water column species, as well as regulatory measures adopted by the various entities, will be discussed. The management of PVS Superfund site may serve as an example for other similar sites in the world.