Dioxins 101

This resource has been factchecked by policy experts, using the latest scientific research. Find all our sources linked below.

What are dioxins?

Dioxins are a group of highly toxic industrial pollutants. They are predominantly produced during processes that involve petrochemicals, for example, in the manufacturing of pesticides and plastics. They’re also produced during smelting, the extraction of metal from its ore, and bleaching paper with chlorine. This can include everyday items like toilet paper and feminine care products. Dioxins can be created when chlorine is burned too—especially during waste incineration that includes plastic.¹ Cars and trucks are another source. While the vast majority of dioxins come from fossil fuels and petrochemicals, they are also released by forest fires, residential wood burning, and volcanoes.^2,3  

There are various types of dioxins. Some are more toxic than others, and they’re all a mouthful, including chlorinated dibenzo-p-dioxins (CDDs) and polychlorinated dibenzofurans (PCDFs). Dioxins belong to the “dirty dozen,” a group of uniquely harmful persistent organic pollutants (POPs), chemicals that have been slated for phase out and elimination. POPs are harmful to human health and the environment, accumulate in fatty tissue, and break down very slowly.^{4, 5, 6} Most human exposure is via food. 

What are the health impacts of dioxins?

Dioxin toxicity is well established. No amount of dioxin exposure is good for us, but dioxins are so pervasive that everyone has at least some level of exposure.

Levels of dioxins have been found in the general US population at or near levels associated with adverse health effects.^{7, 8}

Dioxins can cause cancer, reproductive and developmental problems, and damage to the immune system. They can also interfere with hormones.

Dioxins lodge in our fatty tissues and get stored in our bodies. Rapidly developing babies and children are particularly vulnerable to dioxin exposure, which can stunt growth, result in cognitive impairment, and cause reproductive and developmental problems.^{9, 10} In kids, dioxin exposure has also been associated with decreased learning abilities.¹¹

From air to ground to food to humans

Dioxins can be inhaled from the air or absorbed through the skin.¹² They settle in soil and water. This harms aquatic life and vegetation and creates a risk to people playing or working at homes, parks, playgrounds, and farms. But nothing ever stays put. Dioxins enter the food chain via animals (wild and farmed) and local agriculture. Because dioxins build up and concentrate in fatty tissue, an estimated 90% of human exposure comes from eating fatty foods like meat, dairy, and fish.^{13, 14}

In the news

Dioxins make the news when there are contamination incidents, including the February 2023 train derailment disaster in East Palestine, Ohio.¹⁵ Many of the cars contained vinyl chloride, which burned in uncontrolled conditions for days, creating dioxins and releasing them into the communities surrounding the disaster site.^{16, 17}

Cleanup efforts can be hampered by contradictory government safe threshold standards. For example, the soil in East Palestine had dioxin well above levels that EPA scientists say pose cancer risks, but below levels that trigger federal cleanup.¹⁸

This is not dioxin’s first time in the spotlight, and it won’t be the last. Dioxins were released, for example, during the fires at the World Trade Center as the insulation, plastics, and polyvinyl chloride (PVC) in electrical cables burned.¹⁹ There were also dangerous levels of dioxin in Agent Orange, the herbicide used to clear vegetation in Vietnam.²⁰

What are environmental justice concerns around dioxins?

Occupational exposures and proximity to petrochemical facilities and related industrial sources expose certain communities to higher levels of dioxins. Among those who face the greatest risk are people who work or live near paper industry facilities, PVC plastic production, incineration plants, and other waste and petrochemical sites.^{21, 22, 23} Communities of color are more likely to live near these polluting facilities.^{24, 25} 

People who consume a lot of fish, including Indigenous and subsistence fishing communities, are also at higher risk. A study done in Anniston, Alabama, showed Black Americans and women have higher dioxin body burden than white Americans and men. 

Because children are more vulnerable to dioxin exposure than adults, children of color shoulder the burden of being at highest risk.^{26, 27, 28} 

Mitigating risk

While we can take steps to limit the dioxins we eat, like trimming fat from meat, eating low-fat dairy, or adopting plant-based diets, much of our dioxin exposure is beyond our individual control.

The threat is particularly acute for those whose homes and neighborhoods have been contaminated by toxic air pollution from plastics production facilities, waste incinerators, and chemical disasters.²⁹

Join Moms Clean Air Force in calling on our elected officials and regulatory agencies to crack down on the plastics and petrochemical industries, which are polluting our air with dioxins and other toxic chemicals.

Learn more about Moms' work on vinyl chloride and chemical safety.

Full list of sources.

Released: April 2023