Editing Polychlorinated dibenzodioxins (section)

==Health effects in humans==
[[File:Chloracne-in-herbicide-worker.png|thumb|150px|[[Chloracne]] on the ear and neck of a [[herbicide]] production worker]]
Dioxins build up primarily in fatty tissues over time ([[bioaccumulation]]), so even small exposures may eventually reach dangerous levels. In 1994, the US EPA reported that dioxins are a probable [[carcinogen]], but noted that non-cancer effects (reproduction and sexual development, immune system) may pose a greater threat to human health. [[2,3,7,8-Tetrachlorodibenzodioxin|TCDD]], the most toxic of the dibenzodioxins, is classified as a Group 1 carcinogen by the [[International Agency for Research on Cancer]] (IARC). TCDD has a half-life of approximately 8 years in humans, although at high concentrations, the elimination rate is enhanced by metabolism.<ref name="pmid12107649">{{cite journal | vauthors = Geusau A, Schmaldienst S, Derfler K, Päpke O, Abraham K | title = Severe 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD) intoxication: kinetics and trials to enhance elimination in two patients | journal = Arch Toxicol | volume = 76 | issue = 5–6 | pages = 316–25 | date = June 2002 | pmid = 12107649 | doi = 10.1007/s00204-002-0345-7 | bibcode = 2002ArTox..76..316G | s2cid=5684780}}</ref> The health effects of dioxins are mediated by their action on a cellular receptor, the [[aryl hydrocarbon receptor]] (AhR).<ref name="pmid16545780">{{cite journal | vauthors = Bock KW, Köhle C | title = Ah receptor: dioxin-mediated toxic responses as hints to deregulated physiologic functions | journal = Biochem Pharmacol | volume = 72 | issue = 4 | pages = 393–404 | date = August 2006 | pmid = 16545780 | doi = 10.1016/j.bcp.2006.01.017 }}</ref>

Exposure to high levels of dioxins in humans causes a severe form of persistent [[acne vulgaris|acne]], known as [[chloracne]].<ref name="pmid11564625">{{cite journal | vauthors = Geusau A, Abraham K, Geissler K, Sator MO, Stingl G, Tschachler E | title = Severe 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) intoxication: clinical and laboratory effects | journal = Environmental Health Perspectives | volume = 109 | issue = 8 | pages = 865–9 | date = August 2001 | pmid = 11564625 | pmc = 1240417 | doi = 10.1289/ehp.01109865 | jstor=3454832 }}</ref> High occupational or accidental levels of exposures to dioxins have been shown by epidemiological studies to lead to an increased risk of tumors at all sites.<ref>[http://monographs.iarc.fr/ENG/Monographs/vol69/index.php IARC monograph: "Polychlorinated Dibenzo-''para''-dioxins"]</ref> Other effects in humans (at high dose levels) may include:

*Developmental abnormalities in the [[tooth enamel|enamel]] of children's [[teeth]].<ref name="pmid15345345">{{cite journal |vauthors=Alaluusua S, Calderara P, Gerthoux PM |title=Developmental dental aberrations after the dioxin accident in Seveso |journal=Environ. Health Perspect. |volume=112 |issue=13 |pages=1313–8 |year=2004 |pmid=15345345 |doi= 10.1289/ehp.6920|pmc=1247522 |display-authors=etal  }}</ref><ref name="pmid8260069">{{cite journal | vauthors = Peterson RE, Theobald HM, Kimmel GL | title = Developmental and reproductive toxicity of dioxins and related compounds: cross-species comparisons | journal = Crit Rev Toxicol | volume = 23 | issue = 3 | pages = 283–335 | date = 1993 | pmid = 8260069 | doi = 10.3109/10408449309105013 }}</ref>
*[[Central nervous system|Central]] and [[peripheral nervous system]] pathology<ref name="pmid16898675">{{cite journal |vauthors=Pelclová D, Urban P, Preiss J |title=Adverse health effects in humans exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) |journal=Reviews on Environmental Health |volume=21 |issue=2 |pages=119–38 |year=2006 |pmid=16898675 |doi=10.1515/reveh.2006.21.2.119 |s2cid=44739227 |display-authors=etal  }}</ref>
*[[Thyroid]] disorders<ref name="pmid12821272">{{cite journal | vauthors = Pavuk M, Schecter AJ, Akhtar FZ, Michalek JE | title = Serum 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) levels and thyroid function in Air Force veterans of the Vietnam War | journal = Ann Epidemiol | volume = 13 | issue = 5 | pages = 335–43 | date = May 2003 | pmid = 12821272 | doi = 10.1016/s1047-2797(02)00422-2 }}</ref>
*Damage to the [[immune system]]s<ref name="pmid12460794">{{cite journal |vauthors=Baccarelli A, Mocarelli P, Patterson DG |title=Immunologic effects of dioxin: new results from Seveso and comparison with other studies |journal=Environ. Health Perspect. |volume=110 |issue=12 |pages=1169–73 |year=2002 |pmid=12460794 |pmc=1241102 |doi=10.1289/ehp.021101169 |display-authors=etal  }}</ref>
*[[Endometriosis]]<ref name="pmid12117638">{{cite journal |vauthors=Eskenazi B, Mocarelli P, Warner M |title=Serum dioxin concentrations and endometriosis: a cohort study in Seveso, Italy |journal=Environ. Health Perspect. |volume=110 |issue=7 |pages=629–34 |year=2002 |pmid=12117638 |doi= 10.1289/ehp.02110629|pmc=1240907 |display-authors=etal  }}</ref>
*[[Diabetes]]<ref name="pmid15751269">{{cite journal | vauthors = Arisawa K, Takeda H, Mikasa H | title = Background exposure to PCDDs/PCDFs/PCBs and its potential health effects: a review of epidemiologic studies | journal = J Med Invest | volume = 52 | issue = 1–2 | pages = 10–21 | date = February 2005 | pmid = 15751269 | doi = 10.2152/jmi.52.10 | doi-access = free}}</ref>

Recent studies have shown that high exposure to dioxins changes the ratio of male to female births among a population such that more females are born than males.<ref>{{cite news |url=https://www.reuters.com/article/healthNews/idUSN1836384520071018?feedType=RSS&feedName=healthNews |title=Dioxin pollution leads to more baby girls -study |work= Reuters |access-date=2007-10-22 | date=2007-10-18}}</ref>

Dioxins accumulate in food chains in a fashion similar to other chlorinated compounds ([[bioaccumulation]]). This means that even small concentrations in contaminated water can be concentrated up a food chain to dangerous levels because of the long biological half life and low water solubility of dioxins.