From the 1940s to the early 70s, dichlorodiphenyltrichloroethane, colloquially known as DDT, was the insecticide of choice in America. It was finally banned in 1972 in light of serious concerns about its health and environmental impacts.
But before the chemical’s ban, LA was home to what was at one point the world’s largest DDT manufacturer, the Montrose Chemical Corporation.
The company reportedly dumped as many as a half a million barrels of those toxic chemicals into the ocean around Catalina Island. Now there’s new evidence that shows the sea floor in that area is contaminated with high concentrations of DDT that haven’t broken down.
This has big implications for the local marine ecosystem, according to LA Times Reporter Rosanna Xia.
“DDT is still showing up in very mysterious and concerning ways in California sea lion populations, dolphin populations, and also all the way up the food chain to the California condor,” Xia explains. “All these animals are very much at the top of the marine food chain, which means that this chemical is still clearly accumulating in fish and lower food chain animals in pretty high concentrations across the entire food web.”
The long-term effects of this contamination remain unclear as scientists and policymakers try to find solutions to this and other historical ocean dumping.