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History of Pesticide Disposal off the Coast of Los Angeles

By: Soichiro Tanaka

Huge amount of DDT was found near Santa Catalina Island, California. (Scripps Institution of Oceanography at UC San Diego)

Pesticides have been fundamental to agriculture since the Green Revolution in the 1960s and 1970s. Pesticide use exponentially increased agricultural production globally, nearly quadrupling food grain production in India from 1954. While pesticides’ role in reducing world hunger cannot be understated, the world continues to suffer the side effects of pesticide use without sufficient regulations, as shown in the case of DDT off the coast of Los Angeles, California.

Dichlorodiphenyltrichloroethane, commonly known as DDT, is a type of insecticide that was developed in the 1940s. The US military used DDT during World War II to combat vector-borne diseases such as typhus and malaria common in tropical countries. During the typhus epidemic in Germany and Italy, cases of malaria decreased from 400,000 in 1946 to virtually none in a mere four-year period. After the war, DDT use expanded to agriculture due to its potency, versatility, and reasonable cost. According to the National Pesticide Information Center, production of DDT reached its peak in 1963 at 188 million pounds a year.

Despite the increased productivity of DDT, public health concerns regarding its use started to emerge in the 1960s. After several protests and appeals had taken place in the late 50s, Rachel Carson, a renowned American writer, published Silent Spring in 1962, which “meticulously described how DDT entered the food chain and accumulated in the fatty tissues of animals, including human beings, and caused cancer and genetic damage.”

Silent Spring’s release heightened skepticism surrounding DDT among the American public. Government officials at the time launched a research committee, which confirmed the veracity of Carson’s claim. The book catalyzed increased environmental regulation and the establishment of the EPA in 1970, which would later ban the use of DDT in 1972.

The DDT problems seemed to have been resolved until leaking barrels containing the chemical were discovered near Santa Catalina Island in Los Angeles. Until the early 1970s, the Montrose Chemical Corporation manufacturing plant located in Torrance, California, was one of the largest manufacturers of DDT globally. The company defended the use of DDT despite increasing public disapproval and supplied governments from Brazil to India for malaria eradication. In this process, the company dumped barrels of chemicals near Santa Catalina Island, some of which were punctured for a faster process. The Los Angeles Times estimates that as many as half a million barrels were dumped, which could amount to approximately 384 to 1,535 tons of DDT.

Three decades of dumping toxic chemicals into the ocean were more than enough to affect the ecosystem surrounding the dumping sites. Researchers reported that sea lions with higher concentrations of DDT and other chemicals in their blubber were more prone to having cancer and an unknown herpes virus. Sea lions’ long lifespan makes them susceptible to pollution since they are more prone to chronic accumulation. Due to the amount of DDT remaining on the seafloor, marine animals are continuously threatened by the decade-old chemicals that can climb up the food chain and affect all organisms in the ecosystem.

While some possible solutions, like the removal of the barrels, have been proposed, neither the government nor the public are sure if these steps would be feasible or effective in reducing pollution levels and restoring the damaged ecosystem.  While measures to reverse past disasters are limited, as a community, we can proactively prevent another potentially irreversible disaster such as DDT pollution. By promoting awareness of environmental disasters and advocating for more stringent regulations, we can defend ecosystems from further threats.


Works Cited

Aaron Miguel Cantú. (2021, April 30). California’s legacy of DDT waste: underwater dump site uncovers a toxic history. The Guardian.

DDT - A Brief History and Status. (2023, April 3). EPA. Retrieved January 9, 2024, from

DDT. (2000). National Pesticide Information Center.

DDT Regulatory History: A Brief Survey (to 1975). (2016, September 14). EPA.

NOAA. (2023, November 8). Montrose | Hazardous Waste Site. Retrieved January 9, 2024, from

The Origins of EPA. (2023, June 5). EPA.

The Story of Silent Spring. (2015, August 13). NRDC.

Xia, R. (2020, August 25). How the waters off Catalina became a DDT dumping ground. Los Angeles Times.,even%20the%20most%20dangerous%20poisons

Xia, R. (2021, January 31). Sea lions are dying from a mysterious cancer. The culprits? Herpes and DDT. Los Angeles Times.,even%20the%20most%20dangerous%20poisons


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