Description
DDT is an organochlorine insecticide, once used extensively in the United States in agriculture and for the control of insects carrying malaria and typhus. In 1972, DDT was banned in the U.S., but the U.S. Department of Agriculture and the U.S. military may store and use DDT for public health emergencies. In many developing countries, public health officials continue to rely on DDT to control mosquitoes in an effort to halt the spread of malaria. DDT continues to be manufactured in the U.S. for export. Evidence of DDT’s estrogen-like action was first noted in 1950. DDT is considered a persistent organic pollutant (POP), which tend to remain the environment and animals for long periods of time and can travel long distances. As a result, DDT has been found in animals, such as polar bears, whales and sea birds, quite distant from where it was used. In the U.S., children are exposed to DDT through their food, particularly meat and dairy products, because DDT accumulates in animal fats.
Health Effects
Immediate Health Effects
- If SWALLOWED, dichlorodiphenyltrichloroethane (DDT) is Highly Toxic
- If ABSORBED THROUGH SKIN, dichlorodiphenyltrichloroethane (DDT) is Highly Toxic
- If INHALED (SNIFFED OR BREATHED IN), dichlorodiphenyltrichloroethane (DDT) is Not Available
Longterm or Delayed Health Effects
- This chemical is likely to cause cancer.
- Neurotoxin = Can harm brain and central nervous system
- Suspected Endocrine Disruptor = May interfere with, mimic or block hormones
- Development Toxicant = Can interfere with normal development of a fetus or child
- Reproductive Toxicant = Can harm reproductive system
Other
- Reproductive effects have been observed in animals, including early onset of puberty in females, infertility, and sex reversal (fish). DDE (a breakdown product of DDT) may interfere with the mother’s ability to lactate and can pass to an infant in breast milk; children of mothers with higher levels of DDE in their breast milk fed for shorter times. High DDE levels in mothers’ blood may also increase the likelihood of preterm birth and low birth weight.
- Changes in the normal levels of thyroid hormone.
- Chronic effects on liver, kidney, and nervous system (in laboratory animals).
- Laboratory tests of animals have shown evidence of birth defects (abnormal tail development) and other developmental effects (impaired learning in maze tests). California considers DDT to be a developmental toxicant.
- Large doses ingested result in immediate vomiting due to digestive tract irritation.
- Symptoms of acute poisoning include tingling and numbness of lips, tongue and face, dizziness, tingling in the extremities, confusion, malaise, headache, fatigue, and delayed vomiting.
- Death can result from severe poisoning usually due to respiratory failure.
How Exposures Occur
Breast Milk
- DDT has also been detected in human breast milk. However, the benefits for babies from breast feeding outweigh the risks of DDT exposure. Breast fed babies are healthier than bottle fed, with fewer allergies, respiratory illnesses, and skin problems. In its 2005 policy statement, Breastfeeding and the Use of Human Milk, the American Academy of Pediatrics highly recommends breast feeding for all infants for one year.
Food
- Human exposure occurs from the consumption of foods containing DDT residues, such as meat, fish, poultry, dairy and root and leafy vegetables. Even though DDT has not been used since the 1970s, food continues to contain residues because DDT breaks down very slowly in soil. DDT also drifts on air currents from countries where it is still legal. Nevertheless, the ban on DDT in the U.S. has caused DDT residue on foods in the U.S. to decline in recent decades.
Our exposure to DDT from food primarily comes from meat and dairy products. Fruits and vegetables with the highest levels of DDT residues, according to Consumers Union, include: U.S. grown peaches, frozen winter squash, apples and green beans; Chilean peaches and strawberries; and Mexican tomatoes and spinach. DDT was detected in squash baby food, as well.
Significant Statistics
DDT has been found in arctic and Antarctic animals even though it was never used in those regions. It stays in the environment for long periods and can travel far from where it was originally used.
Public Health Statement for DDT, DDE, and DDD. Agency for Toxic Substances and Disease Registry. September 2002. http://www.atsdr.cdc.gov/phs/phs.asp?id=79&tid=20.
In the US, food, particularly meat, fish and dairy, are the primary sources of exposure. Exposure rates have gone down since DDT was banned. Food imported from countries that still use it can contain residue.
Fourth National Report on Human Exposure to Environmental Chemicals. Centers for Disease Control and Prevention. 2009. http://www.cdc.gov/exposurereport/pdf/FourthReport.pdf.
DDT is banned in the United States, but it can still be used in public health emergencies under the Public Health Service’s supervision.
Report on Carcinogens, Eleventh Edition; U.S. Department of Health and Human Services, Public Health Service, National Toxicology Program . http://ntp.niehs.nih.gov/index.cfm?objectid=32BA9724-F1F6-975E-7FCE50709CB4C932.
Solutions
How to detect dichlorodiphenyltrichloroethane (DDT)
How to minimize exposure to dichlorodiphenyltrichloroethane (DDT)
Alternatives
- Eat a balanced diet, with plenty of fruits and vegetables and a moderate level of low-fat meats and dairy products.
- Choose certified organic foods, when possible, as they have not been treated with pesticides. A good place to start is with 10 Fruits and Vegetables to Buy Organic.
- Consumer Reports recommends avoiding consumption of U.S. frozen winter squash due to high pesticide residue levels.
- Peeling and washing fresh produce can help remove some surface pesticide residues, including DDT.
- Reduce dietary fat to decrease DDT intake. Remove fat from meat as well as skin on chicken and fish, before cooking. Use cooking methods such as broiling, which allows fat to drip away from the food. Deep frying may seal in toxins. Saute and fry with vegetable oil rather than butter.
For More information
Books, articles, factsheets and reports
Carson, Rachel. Silent Spring. Houghton Mifflin Co., September 1994.
Kert, Richard Wiles. Pesticides in Baby Food. Environmental Working Group, June, 1995.
http://www.ewg.org/reports/baby_food.
Report Card: Pesticides in Produce. Environmental Working Group, October 2003.
http://www.foodnews.org/reportcard.php
Other government agencies
U.S.Environmental Protection Agency
Persistent, Bioaccumulative and Toxic Chemical Program
Office of Pollution Prevention and Toxics
1200 Pennsylvania Ave.
Washington DC 20460
202-260-2090
http://www.epa.gov/pbt/
Nonprofit organizations
Pesticides Action Network North America
49 Powell St. Suite 500
San Francisco, CA 94102
415-981-1771
http://www.PANNA.org
Other websites
Our Stolen Future
http://www.ourstolenfuture.org
Healthy Babies, Healthy Milk
http://www.nrdc.org/breastmilk/default.asp
