Description
There are 75 related forms of dioxin, all organochlorine compounds, which share similar properties. Dioxins are potent chemicals that are known to cause cancer and damage to the brain and central nervous system. The most toxic is 2,3,7,8-tetrachlorodibenzo-para-dioxin, or TCDD. Dioxins are now widespread in the environment.
Dioxins are byproducts of manufacture involving chlorine. They are formed during combustion and during the production of chemical compounds containing chlorine, such as pesticides and PCBs. The production and use of some chlorinated chemicals, bleaching of paper, and waste incineration, including the uncontrolled burning of residential waste, are the major sources of dioxins.
Dioxins are considered persistent organic pollutants (POPs), which tend to remain in the environment and animals for long periods of time and can travel long distances.
Children are exposed to dioxin through food, primarily meat and dairy products. Dioxin can cross the placenta to expose babies in the womb. Breastfed infants are also exposed to dioxin that has accumulated in breast milk. (All women have some amount of dioxin in their breast milk, and infants may receive concentrated levels of dioxin through breast milk.) Despite this, the American Academy of Pediatrics still recommends breast milk as the best food for babies. Even infant formulas can contain some amount of dioxins.
Fetuses and breastfeeding infants may be at particular risk from exposure to dioxins and dioxin-like compounds because they may cause harm to the developing brain and immune system.
Note: Toxicity information below is for TCDD. Other dioxins vary in their toxicity. TCDD is the most toxic of all dioxins.
Health Effects
Immediate Health Effects
- If SWALLOWED, dioxins is Very Highly Toxic
- If ABSORBED THROUGH SKIN, dioxins is Very Highly Toxic
- If INHALED (SNIFFED OR BREATHED IN), dioxins is Not Available
Longterm or Delayed Health Effects
- 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
Other
- Developmental toxicity, including reduced viability, low birth weight birth defects such as skeletal deformities and kidney defects impaired reproductive system development, and functional alterations, such as effects on thyroid function, neurodevelopmental delays and impaired cognitive ability.
- Cancer, including thyroid tumors, soft tissue sarcoma, non-Hodgkin’s lymphoma, Hodgkin’s disease.
Impaired immune function.
- Reproductive effects, including decreased sperm production, altered levels of sex hormones, decreased fertility and increased rate of miscarriage have been observed in laboratory animals exposed to TCDD.
An association between exposure to dioxin and diabetes mellitus has been observed although a cause-effect relationship has not been established.
- Exposure to high levels can cause chloracne, a severe acne-like skin rash associated with exposure to organochlorine chemicals.
- Rashes, skin discoloration, excessive body hair
- Liver damage
How Exposures Occur
Food
- Food accounts for 95 percent of human exposure to dioxin. Since dioxins accumulate in the fat of animals, the highest sources in the human diet are found in beef, pork, lamb, fish, shellfish, butter, cheese, processed meats, eggs, poultry, and milk. Dioxins can also be taken up by plants; usually the concentrations are considerably lower, though.
Breast Milk
- Dioxins are also found in human breast milk. There is a potential for infants to receive fairly high levels of dioxin. However, the benefits for babies from breast feeding outweigh the risks of dioxin exposure. Breastfed babies are healthier than those who are bottle-fed; they experience fewer allergies, respiratory illnesses, and skin problems. In its 1997 policy statement, Breastfeeding and the Use of Human Milk, the American Academy of Pediatrics highly recommends breast feeding for all infants for one year. Note that an attempt to reduce dioxin in breast milk during pregnancy or postpartum will have no significant impact on the mother’s level or the baby’s exposure.
During Pregnancy
- The fetus can be exposed through the placenta to dioxin that has accumulated in the mother’s body throughout her lifetime. Waiting until pregnancy to reduce dioxin intake has no significant impact on the mother’s level or the baby’s exposure.
Drinking Water
- Dioxin released in the air can be deposited on the ground and then washed into water systems. However, dioxin is not very water-soluble. Most will bind to soils and sediment, and accumulate in animal tissue, making exposure to dioxin through water unlikely.
Skin Contact
- Skin contact with some pesticides may result in exposure.
Significant Statistics
TCDD accumulates in animals and can be found in higher concentrations at higher levels of the food web.
Public Health Statement for Chlorinated Dibenzo-p-dioxins (CDDs). Agency for Toxic Substances and disease Registry. March 1, 2010. http://www.atsdr.cdc.gov/PHS/PHS.asp?id=361&tid=63.
95% of human exposure to dioxins comes from dietary intake of animal fat.
Information Sheet :1Dioxin: Summary of the Dioxin Reassessment Science. US Environmental Protection Agency. October 15, 2004. http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=87843.
TCDD was found in Agent Orange, the chemical defoliant used during the Vietnam War, and Air Force veterans who were responsible for spraying the chemical have elevated exposure to TCDD.
2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD); “Dioxin” CAS No. 1746-01-6. Report on Carcinogens, Eleventh Edition; U.S. Department of Health and Human Services, Public Health Service, National Toxicology Program. http://ntp.niehs.nih.gov/ntp/roc/eleventh/profiles/s168tcdd.pdf.
Solutions
How to detect dioxins
- Food: There is no way for parents to determine exactly how much dioxin is in their children’s food. The highest sources in the human diet are found in beef, chicken, pork, fish, shellfish, cheese, milk and eggs.
Avoid eating fish from bodies of water with fish advisories in effect. You can find state and federal fish advisories through the EPA’s list of State Fish Consumption Advisory Links.
Dioxin levels tend to be highest in fatty fish from contaminated areas near industries that produce dioxin. The fish and seafood likely to have high dioxin levels include bluefish, Great Lakes lake trout and salmon, the mustard of crab, and tomalley of lobster. Generally, high fat-content, bottom fish, collected close to the contaminant source, have the highest levels, whereas lower-fat, nonstationary fish have much lower concentrations, even in the vicinity of the contaminant source. See our Fish Toxins chart (PDF) for more on dioxins and fish. For more information on which fish contain the highest toxin levels, see the Safe Fish CHEC List for Children, Teens and All Women of Child-bearing Age. You can also check out the Environmental Working Group’s Seafood Selector.
- Drinking Water: Dioxin is regulated under the Safe Drinking Water Act. This law requires that community water systems monitor dioxin levels, and make public when levels exceed the set Maximum Contamination Level (MCL). The MCL for dioxin is 0.00003 parts per billion.
Community water systems are required to produce annual consumer confidence reports and mail them to every water customer.
If your water source is a well, your water is not monitored for contaminants as is required for public water supplies by the Safe Drinking Water Act. Private testing of the water is necessary. Even if your water comes from a community water system, contaminant levels can vary from house to house. You can have your water tested by sending samples to a certified laboratory.
You can search for water quality reports from your water provider, obtain information on well water testing and find a list of state-certified drinking water laboratories at the U.S. EPA’s Office of Water’s website, or call the EPA’s Safe Drinking Water Hotline, 800-426-4791.
- To find out whether dioxin has been released in your neighborhood, visit Environmental Defense’s Scorecard for chemicals or call the Community-Right-to-Know information line, 800-535-0202, for information on chemical releases in your state.
How to minimize exposure to dioxins
- Avoid sauces made from liquid fish drippings or cooking water, and avoid stews and soups that call for whole fish with internal organs intact. Avoid the "mustard" in blue crab and the "tomalley" in lobster. See also: Seafood Selector.
- Reduce consumption of high-fat meats, fish, poultry and dairy products such as butter, cheese and ice cream.
- Efforts to keep dioxin exposure low MUST begin in childhood, since dioxin accumulates over time and does not break down for decades, in some cases. In 2003, an expert panel of the Institute of Medicine released a report, Dioxins and Dioxin-like Compounds in the Food Supply: Strategies to Decrease Exposure, which recommended following a low-fat diet with moderate amounts of animal foods, including low- or no-fat dairy products and fatty fish. The report stressed that lowering dioxin levels is particularly important for girls and young women, who will pass on some of the dioxin in their bodies to their children.
Alternatives
- Eat a balanced diet, with plenty of fruits and vegetables and a moderate level of low-fat meats and dairy products. While organic foods are not any less likely to contain dioxins, they may contain fewer pesticides and other hormone disrupting chemicals. Mothers & Others’ New Green Diet is a good place to start.
- Serve smaller portions of meat, choose low-fat or skim milk and dairy products, and reduce overall intake of animal products. This is particularly important for girls and women of child-bearing age.
- Reduce dietary fat to decrease dioxin intake. Remove fat from meat as well as skin on chicken and fish, before cooking. Trim any darker meat along the top or center of the fillet. Use cooking methods such as broiling, which allows fat to drip away from the food.
For More information
Books, articles, factsheets and reports
Questions and Answers About Dioxin. U.S. Food and Drug Administration, May 2010.
Gibbs, Lois Marie. Dying from Dioxin: A Citizen's Guide to Reclaiming Our Health and Rebuilding Democracy. Boston: South End Press, 1995.
Thornton, Joe. Pandora’s Poison: Chlorine, Health, and a New Environmental Strategy. Cambridge, Massachusetts: MIT Press, 2000.
Other government agencies
U.S.Environmental Protection Agency
Office of Pollution Prevention and Toxics
Persistent Bioaccumulative and Toxic (PBT) Chemical Program
1200 Pennsylvania Ave.
Washington DC 20460
202-260-2090
http://www.epa.gov/opptintr/pbt/
Nonprofit organizations
Center for Health, Environment and Justice
P.O.Box 6806
Falls Church, VA 229040
703-237-2249
http://www.chej.org
Institute for Agriculture and Trade Policy
2105 First Avenue South
Minneapolis, MN 55404
612-870-3424
http://www.iatp.org/edrc
Other websites
Our Stolen Future
http://www.ourstolenfuture.org
Healthy Babies, Healthy Milk
http://www.nrdc.org/breastmilk/default.asp
Center for Bioenvironmental Research at Tulane and Xavier Universities
http://e.hormone.tulane.edu/
World Health Organization: Dioxins and their Effects on Human Health
http://www.who.int/mediacentre/factsheets/fs225/en/
