Toxic pesticides dumped off Southern California's coast decades ago are staying put — deep in adjacent ocean sediments and in the fish that reside in these habitats, a new study has found.

Current levels of dichlorodiphenyltrichloroethane (DDT), an agricultural insecticide banned in 1972, remain highest in sediments and fish located closest to the old discharge sites, according to the study, published on Monday in the Proceedings of the National Academy of Sciences.

DDT contamination remains persistent in the Palos Verdes region about 15 miles off the coast of Catalina Island, according to the previous research.

From about 1948 to 1961, barges contracted by DDT-producer Montrose Chemical Corporation released waste that held up to 2 percent pure DDT directly into the Pacific Ocean in this area, past studies have shown.

An estimated 100 tons of the chemical ended up in the........

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