chemical information


Chemical Class:

Chlorinated dioxin

Chemical SubClass

Heptachlorinated dioxin

Manufacturing/Use Status

this chemical is not intentionally produced, it is a byproduct of another application

Found in these people:

Baby #6, Baby #5, Baby #7, Baby #9, Baby #3, Baby #2, Baby #1, Baby #10, Baby #8, Baby #4, Michael Lerner, Davis Baltz, Anonymous Adult 1, Charlotte Brody, Lexi Rome, Kathy Fowler, Monique Harden, U.S. Representative Louise Slaughter, Andrea Martin, Lucy Waletsky, Sharyle Patton, Bill Moyers, Cord Blood Sample 16, Cord Blood Sample 17, Cord Blood Sample 18, Cord Blood Sample 19, Cord Blood Sample 14, Cord Blood Sample 15, Cord Blood Sample 11, Cord Blood Sample 12, Cord Blood Sample 13

Found in these locations:

Bolinas, CA; Berkeley, CA; Round Hill, VA; Mill Valley, CA; Rockville, MD; New Orleans, LA; Upstate New York, NY; Sausalito, CA; Pleasantville, NY; NJ, USA


Dioxins cause toxicity to many organ systems in animals. Effects include liver and thyroid tumors; cardiovascular, skeletal, skin, immune, respiratory, neurological and reproductive toxicity; altered lipid and carbohydrate metabolism; reduced fertility and birth defects. Specific birth defects include reproductive tract and skeletal abnormalities, such as cleft palate (ATSDR 1998a). Dioxins are endocrine disruptors because they alter thyroid, reproductive, and adrenal hormone levels and function (ATSDR 1998a). Many of the lowest dose effects are developmental. For example, a one-time exposure to dioxin during fetal life can impair prostate development in male rats (Roman 1998a, b; Timms 2002).

The effects of dioxins have been studied in humans who were exposed through diet, work, military service and industrial accidents. Dioxin (TCDD) is a known human carcinogen. It is associated with increased incidence of cancer in general and with non-Hodgkin's lymphoma and lung and soft-tissue cancer in particular (ATSDR 1998a; NTP 2002). Soft tissue includes muscle, fat, blood vessels or any of the other tissues that support, surround and protect organs of the body. Dioxin is also associated with non-cancer disorders including skin lesions (chloracne), and nervous system toxicity (ATSDR 1998a). Associations with other types of disorders are emerging. For example, recent follow-up of people exposed to an industrial explosion in Seveso, Italy (the highest known population exposure to TCDD) suggest that dioxin may also be associated with breast cancer (Warner 2002), menstrual irregularities (Eskenazi 2002), altered thyroid function, and diabetes (Kogevinas 2001). Risk of developing diabetes or glucose intolerance is also increased in military personnel who were exposed to dioxin-contaminated herbicide (Agent Orange) in the Vietnam War (Longnecker 2001). Although developmental effects of dioxin have not been adequately studied in humans, several studies have linked dioxin to altered sex ratio (in favor of females) (Mocarelli 2000).

1,2,3,4,6,7,8-HpCDD (heptadioxin)

In dioxin family of chemicals - pollutants from PVC production, industrial bleaching, incineration; cause cancer, may harm hormone system.

1,2,3,4,6,7,8-HpCDD (heptadioxin) has been found in 33 of the 34 people tested in EWG/Commonweal studies. It has also been found in 2,333 of the 4,821 people tested in CDC biomonitoring studies.

Top health concerns for 1,2,3,4,6,7,8-HpCDD (heptadioxin) (References)

health concern or target organ weight of evidence
Immune system (including sensitization and allergies)limited
Birth defects and developmental delaysunknown

Results for 1,2,3,4,6,7,8-HpCDD (heptadioxin)

in blood serum (lipid weight)

Showing results from Pollution in Minority Newborns, EWG/Commonweal Study #4, industrial chemicals and pesticides in cord blood, San Francisco Reporter, EWG/Commonweal Study #1, industrial chemicals and pesticides in adults, EWG Study #3, industrial chemicals and pesticides in adults

EWG/Commonweal results

  • geometric mean: 19.9 pg/g (lipid weight) in blood serum
  • found in 33 of 34 people in the group

CDC biomonitoring results

  • geometric mean: 10.4 pg/g (lipid weight) in blood serum
  • found in 2333 of 4821 people in the group
pg/g (lipid weight) in blood serum 2470

1,2,3,4,6,7,8-HpCDD (heptadioxin) results

Detailed toxicity classifications (References)

classification governing entity/references
Limited evidence in humans - immune system toxicityATSDR (1998). Toxicological profile for chlorinated dibenzo-o-dioxins (CDDs): Health effects chapter.
Birth defects - weight of evidence unknown/unassessedATSDR (1998). Toxicological profile for chlorinated dibenzo-o-dioxins (CDDs): Health effects chapter.