Halogenated organic compounds (HOCs) have a sordid past in American history. Polychlorinated HOCs, such as the agricultural insecticides dichlorodiphenyltrichloroethane (DDT) and chlordane and industrial (dielectric and coolant) fluids based on polychlorinated biphenyls (PCBs), were once widely used household and industrial chemicals that greatly benefited mankind. The severe environmental impact of DDT to wildlife and humans, however, eventually led to its ban in the US in 1972 and is credited with starting the environmental movements of the 1960s that ultimately recognized polychlorinated HOCs as persistent organic pollutants with notorious genotoxic and xenoestrogenic activities. However, despite their restricted or banned usage, their environmental presence as “legacy chemicals” is still felt today due to their persistent, bioaccumulative, and food web biomagnification properties.
Without a doubt, halogenated organic compounds represent a growing marine environmental concern relevant to human health. The sources of polybrominated diphenyl ethers (PBDEs), polybrominated dibenzo-p-dioxins (PBDDs), and polybrominated bipyrroles (PBPs) include both anthropogenic and natural origins. Amazingly, the main source organisms for the production of natural polybrominated organic compounds have eluded detection, and thus the environmental contribution of natural pathways to these toxic halogenated molecules is unknown.
The goal of the Scripps Center for Oceans and Human Health is to characterize the biological sources, distributions, chemical composition, biosynthetic mechanisms, exposure and toxicity of the natural, polybrominated and mixed halogenated organic compounds that are accumulating globally in marine mammals, fish, and shellfish, and also shown to be present in human breast milk. The Scripps Center for Oceans and Human Health is structured into three highly collaborative and integrated Projects (P1, P2 and P3) involving six independent scientists and their collaborators. This configuration is organized around the central themes of the Center, which is to discover the main marine sources and sinks of natural polybrominated organic compounds (P1), the molecular basis of polybrominated organic compound biosynthesis in the marine environment (P2), and the distribution, provenance, and human health implications of marine polybrominated organic compounds (P3). These three Projects pair investigators with complementary expertise and with a history of collaborative research to tackle for the first time in a systematic fashion the origin and marine food web distribution of polybrominated HOCs of human health concern.
With $6 million in joint funding from the National Institutes of Health and the National Science Foundation, the new Scripps Center for Oceans and Human Health will track natural chemicals known as halogenated organic compounds, or HOCs. Human-manufactured varieties include polybrominated diphenyl ethers, or PBDEs, chemicals that until recently were manufactured and broadly used in commercial products as flame retardants in the textile and electronics sectors.