In a Los Angeles Times news article published in October of 2020, the author chronicles the history and discovery of half a million barrels of DDT that were dumped off the coast of Santa Catalina Island in California between 1947 – 1982 (Xia, 2020). During that time, one of the largest manufacturers of DDT was based in Los Angeles, and it was praised for being on the forefront of (what was thought of at the time as being) “the greatest contribution to the future of the health world”. The US alone would use more than 80 million pounds of DDT annually (Xia, 2020). However, when the chemical was eventually banned in 1972, the production plants like the one in LA had to figure out how to dispose of the chemical. Instead of properly disposing of the barrels of DDT, workers at the plant decided to dump the barrels into the Santa Monica Basin. If the barrels were floating, they would even puncture them so that would sink to the bottom of the ocean. This is an improper method of disposal for the chemical and has caused a plethora of environmental and health problems including contamination of phytoplankton, fish, pelicans and other birds, and sea lions (Xia, 2020).

DDT is an insecticide most commonly used in agriculture in order to manage crops. Although the chemical was banned by the United States in 1972, a lot of countries still use the chemical. It also has historically been used in the treatment of lice, and in other countries is used in the prevention of mosquitos and malaria (“DDT- A Brief History and Status”, 2021). Combating malaria and other insect-vector diseases was the original intent of DDT, and it was widely utilized during the Allies in WWII for that purpose. However once it was realized how effective DDT was in insect control, it began to be utilized on an industrial agricultural scale and even in personal homes and gardens (“DDT Factsheet”, 2017).

Image of beachgoers being sprayed with DDT

People can be exposed to DDT from eating foods grown in places where DDT was used, or from eating meat, fish, or dairy products. DDT is transmitted to humans through ingestion or absorbed through breathing or touching contaminated products. When in the body, following high doses of exposure, DDT can cause nausea and vomiting, shakiness, and seizures. Fortunately, indirect exposure to DDT is considered non-toxic to humans. In lab samples and experiments, DDT also caused liver problems and led to reproductive issues. Although more research needs to be done, DDT is also considered a human carcinogen – which is a cancer-causing substance (“DDT Factsheet”, 2017). Preventative efforts have been effective in the ban of DDT and in limiting its subsequent harmful health effects, however, discoveries like that found in the Pacific Ocean detailed in the news report remind us of the harmful history we have with DDT and how it’s consequences are still salient today.

References:

Dichlorodiphenyltrichloroethane (DDT) FACTSHEET. (2017, April 07). Retrieved March 24, 2021, from https://www.cdc.gov/biomonitoring/DDT_FactSheet.html

Ddt – a brief history and status. (2021, March 17). Retrieved March 24, 2021, from https://www.epa.gov/ingredients-used-pesticide-products/ddt-brief-history-and-status

Xia, R. (2020, October 25). How the waters off Catalina became a DDT dumping ground. Retrieved March 24, 2021, from https://www.latimes.com/projects/la-coast-ddt-dumping-ground/