Agency for Toxic Substances & Disease Registry
Dioxins
Dioxins are a group of 75 different compounds. They are also known as chlorinated dibenzo-p-dioxins (CDDs). Dioxins are known to occur naturally, and are also produced by human activities. They are naturally produced from the incomplete combustion of organic material by forest fires or volcanic activity. Dioxins are not intentionally manufactured by industry, except in small amounts for research purposes. They are unintentionally produced by industrial, municipal, and domestic incineration and combustion processes. Currently, it is believed that dioxin emissions associated with incineration and combustion activities are the predominant environmental source. Dioxins generally enter the environment as mixtures of different dioxin compounds. The most heavily studied compound — 2,3,7,8-TCDD — is formed during the chlorine bleaching process at pulp and paper mills and during the manufacture of some pesticides and herbicides.
Studies have shown that exposure to 2,3,7,8-TCDD increases the risk of several types of cancer in animals. Liver damage has been observed in some people exposed to dioxins. Some studies suggest that dioxin increases the risk of certain types of cancer in humans. Other studies don't show any connection between dioxin exposure and cancer. The most common health effect in humans is chloracne. Chloracne is a severe skin disease, characterized by large, deep acne-like lesions.
Dioxins that enter the soil or water may build up in the food chain, resulting in measurable levels in animals. According to the Agency for Toxic Substances and Disease Registry, more than 90 percent of the intake of CDDs in the general population occurs through consumption of meat, dairy products, and fish.
Dioxins are common fish contaminants. The N.C. Department of Environmental Quality (DEQ) routinely monitors water quality and fish tissue for potential problems (Learn more about the DEQ Water Sciences Section). In the event that potentially hazardous levels of chemicals are detected in fish, the N.C. Department of Health and Human Services (DHHS) issues public advisories telling people to either limit consumption or, if necessary, avoid eating those kinds of fish entirely. All of North Carolina's dioxin-related fish consumption advisories are related to paper mills. All of the paper mills have made substantial changes to their processes to reduce or prevent dioxin formation; however, advisories are still in effect for some sites.
Current dioxin-related fish advisories in effect for North Carolina are available on the Occupational and Environmental Epidemiology Current Fish Advisories page as well as through the U.S. Environmental Protection Agency.