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Revisiting DDT Pollution in California Ocean and Wildlife 50 Years after Its Ban

Eunha Hoh, Professor, School of Public Health, San Diego State University

Mar 4 2024 | 11:00am to 12:00pm PT Bren Hall 1414 / Online

Headshot of Eunha Hoh
Eunha Hoh

Using state-of-the-art approaches, Eunha Hoh's research uncovers anthropogenic chemicals and metabolites entering the built and natural environments. Her work exposes feedbacks between human behavior, and human and environmental health, all critical for informing safe product, chemical, and pollution management policies.
—Patricia Holden, Professor, Bren School


DDT is an insecticide widely used globally. In the United States, DDT was banned 50 years ago because of its potential human carcinogenicity and harmful effects in wildlife. One of the major DDT manufacturers was near LA and its wastewater discharge polluted the nearby coast. Recently, an offshore dumping site of DDT barrels was discovered near Catalina Island, which alerts further concerns of DDT pollution in the California ocean. Our research group has studied marine mammals’ exposure to halogenated organic contaminants (HOCs) including DDT in California coast. Marine mammals are top predators in food chains and susceptible to high exposure of bioaccumulate and biomagnifying contaminants like HOCs. We found that marine mammal blubbers collected in the Southern California Bight contained highest DDT concentrations globally. We discovered 45+ DDT related compounds (DDT+) via a novel analytical approach, nontargeted analysis. Among the DDT+, novel contaminants, impurity of DDT technical product was highly concentrated in the marine mammal blubbers. We also found that condors habituated in California coastal sites had much higher exposure to DDT+ compounds including the impurity compounds compared to ones in California inland sites. Through our recent collaboration with oceanographers, we found transport of DDT+ from deep ocean sediment to deep ocean biota in the Southern California Bight for the first time. This talk will focus on California wildlife’s exposure to DDT+ and discuss potential concerns on human health regarding DDT+.


Dr. Eunha Hoh is a Professor of Environmental Health in the School of Public Health at San Diego State University. She received her doctoral degree in Environmental Science in 2006 at Indiana University at Bloomington and worked as a postdoctoral researcher in the field of food safety at the USDA Agricultural Research Service. Her primary research interests focus on the investigation of diverse pollutants in the environment and their impact on human and wildlife health. Her current research projects focus on ocean and human health, fate and transport of environmental contaminants, and the discovery of novel contaminants and their sources. She was one of six PIs of the Scripps Center for Oceans and Human Health and a Scientific Guidance Panel member for the California Environmental Contaminant Biomonitoring Program. She is a member of the California Ocean Protection Council’s Science Advisory Team, an expert interdisciplinary group formed to address issues impacting the state’s coastal and marine ecosystems. She is a member of the Ocean Research Advisory Panel (ORAP), a Federal advisory committee to advise the Ocean Policy Committee on certain science and research policies, procedures, and priorities.

Please note this talk was not recorded.


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