DDT leaves behind a legacy of long-lasting contamination and harm to both humans and ecosystems. Banned in the U.S. nearly 40 years ago, DDT and its breadown products were found in the blood of 99% of people recently tested by the CDC. USDA found DDT breakdown products in 60% of heavy cream samples, 42% of kale greens, 28% of carrots and lower percentages of many other foods.
The science on DDT's human health impacts has continued to mount over the years, with recent studies showing harm at very low levels of exposure. Studies show a range of human health effects linked to DDT and its breakdown product, DDE:
[Text Box: Childhood Exposure & Body Burden: Research shows that childhood exposure to DDT begins before birth.
DDT's toxic effects on ecosystems are well known. DDT concentrates up the food chain, reaching high levels in fish and marine mammals. DDT can travel long distances in the atmosphere, which is why it is found on almost every corner of the earth and in places where it has never been used. In the Arctic and Antarctic regions, research shows DDT and its breakdown products in the atmosphere, snow, and wildlife.
[Text Box: Environmental Persistence: Despite bans, DDT can persist in the environment for decades:
Experience tells us that eliminating DDT generally improves the health of ecosystems. Since DDT was banned in the U.S., bald eagles have made a dramatic recovery, along with a several other bird species. An Environmental Defense Fund article summarizes:
Wiping out malaria with DDT is an unrealistic goal. Mosquito resistance among malaria carrying mosquitos forced governments years ago to adopt a more diverse, integrated approach to malaria control.
Long before the United States banned DDT, mosquito populations evolved defenses to DDT's toxins. Mosquitos showed signs of resistance to DDT as early as 1947---only one year after the insecticide was introduced for mosquito control (See: Insecticide Resistance in Insect Vectors of Human Disease). By 1972, nineteen species of mosquitos were resistant to DDT in Africa alone.
[Text Box: Malaria Eradication in the United States:
Once endemic in the United States, malaria decreased rapidly in the first half of the 20th century, without the insecticidal powers of DDT. According to the CDC, from 1920 to 1946, malaria cases decreased from 400 out of 100,000 inhabitants to only 30 cases per 100,000. Malaria deaths likewise decreased from 60 deaths per million to only 2 deaths per million. In 1947 the U.S. commenced the National Malaria Eradication Program which included drainage, removal of mosquito breeding grounds, and some DDT in areas where malaria was still prevelant. ]
Research & Factsheets
Additional Health Research: Reproductive Harm:
Addition Health Research: Infants and Breastmilk