Editing Polychlorinated dibenzodioxins (section)

==Toxic effects in animals==
While it has been difficult to establish specific health effects in humans due to the lack of controlled dose experiments, studies in animals have shown that dioxin causes a wide variety of toxic effects.<ref name=Pohjanvirta>R. Pohjanvirta, J. Tuomisto, Short-term toxicity of 2,3,7,8-tetrachlorodibenzop- dioxin in laboratory animals: effects, mechanisms, and animal models, Pharmacological Reviews 1994: 46: 483–549.</ref> In particular, [[tetrachlorodibenzodioxin|TCDD]] has been shown to be [[teratogenic]], [[mutagenic]], [[carcinogenic]], [[immunotoxic]], and [[hepatotoxic]]. Furthermore, alterations in multiple [[endocrine]] and [[growth factor]] systems have been reported. The most sensitive effects, observed in multiple species, appear to be developmental, including effects on the developing [[immune]], [[nervous system|nervous]], and [[reproductive system]]s.<ref name="pmid10912242">{{cite journal |author=Birnbaum LS, Tuomisto J |title=Non-carcinogenic effects of TCDD in animals |journal=Food Additives and Contaminants |volume=17 |issue=4 |pages=275–88 |year=2000 |pmid=10912242 |doi=10.1080/026520300283351|last2=Tuomisto |s2cid=45117354 }}</ref> The most sensitive effects are caused at [[body burden]]s relatively close to those reported in humans.

Among the animals for which TCDD toxicity has been studied, there is strong evidence for the following effects:

*Birth defects ([[teratogenic]]ity)

:In rodents, including rats,<ref name="pmid16835633">{{cite journal |title=NTP technical report on the toxicology and carcinogenesis studies of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) (CAS No. 1746-01-6) in female Harlan Sprague-Dawley rats (Gavage Studies) |journal=National Toxicology Program Technical Report Series |issue=521 |pages=4–232 |year=2006 |pmid=16835633|last1= National Toxicology |first1= Program}}</ref> mice,<ref name="pmid10048156">{{cite journal | vauthors = Peters JM, Narotsky MG, Elizondo G, Fernandez-Salguero PM, Gonzalez FJ, Abbott BD | title = Amelioration of TCDD-induced teratogenesis in aryl hydrocarbon receptor (AhR)-null mice | journal = Toxicol Sci | volume = 47 | issue = 1 | pages = 86–92 | date = January 1999 | pmid = 10048156 | doi = 10.1093/toxsci/47.1.86 |doi-access=free  }}</ref> hamsters and guinea pigs,<ref name="pmid17126467">{{cite journal | vauthors = Kransler KM, McGarrigle BP, Olson JR | title = Comparative developmental toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin in the hamster, rat and guinea pig | journal = Toxicology | volume = 229 | issue = 3 | pages = 214–25 | date = January 2007 | pmid = 17126467 | doi = 10.1016/j.tox.2006.10.019 | bibcode = 2007Toxgy.229..214K }}</ref> birds,<ref name="pmid14522596">{{cite journal | vauthors = Bruggeman V, Swennen Q, De Ketelaere B, Onagbesan O, Tona K, Decuypere E | title = Embryonic exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin in chickens: effects of dose and embryonic stage on hatchability and growth | journal = Comp Biochem Physiol C | volume = 136 | issue = 1 | pages = 17–28 | date = September 2003 | pmid = 14522596 | doi = 10.1016/s1532-0456(03)00168-6 }}</ref> and fish.<ref name="pmid16333842">{{cite journal | vauthors = Carney SA, Prasch AL, Heideman W, Peterson RE | title = Understanding dioxin developmental toxicity using the zebrafish model | journal = Birth Defects Res A | volume = 76 | issue = 1 | pages = 7–18 | date = January 2006 | pmid = 16333842 | doi = 10.1002/bdra.20216 }}</ref>
*Cancer (including [[neoplasms]] in the mammalian lung, oral/nasal cavities, [[thyroid]] and [[adrenal]] glands, and liver, [[squamous cell]] carcinoma, and various animal [[hepatocellular carcinoma|hepatocarcinomas]])

:In rodents<ref name="pmid16835633"/><ref name="pmid9061855">{{cite journal |author=Mann PC |title=Selected lesions of dioxin in laboratory rodents |journal=Toxicologic Pathology |volume=25 |issue=1 |pages=72–9 |year=1997 |pmid=9061855 |doi=10.1177/019262339702500114|s2cid=9819569 |doi-access=free }}</ref> and fish.<ref name="pmid10720744">{{cite journal | vauthors = Grinwis GC, Vethaak AD, Wester PW, Vos JG | title = Toxicology of environmental chemicals in the flounder (Platichthys flesus) with emphasis on the immune system: field, semi-field (mesocosm) and laboratory studies | journal = Toxicol Lett | volume = 112-113 | issue = | pages = 289–301 | date = March 2000 | pmid = 10720744 | doi = 10.1016/s0378-4274(99)00239-8 }}</ref>

*Hepatotoxicity (liver toxicity)

:In rodents,<ref name="pmid9061855"/> chickens,<ref name="pmid11489429">{{cite journal | vauthors = El-Sabeawy F, Enan E, Lasley B | title = Biochemical and toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin in immature male and female chickens | journal = Comp Biochem Physiol C | volume = 129 | issue = 4 | pages = 317–27 | date = August 2001 | pmid = 11489429 | doi = 10.1016/s1532-0456(01)00199-5 }}</ref> and fish.<ref name="pmid14687977">{{cite journal | vauthors = Zodrow JM, Stegeman JJ, Tanguay RL | title = Histological analysis of acute toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in zebrafish | journal = Aquat Toxicol | volume = 66 | issue = 1 | pages = 25–38 | date = January 2004 | pmid = 14687977 | doi = 10.1016/j.aquatox.2003.07.002 | bibcode = 2004AqTox..66...25Z }}</ref>

*Endocrine disruption

:In rodents<ref name="pmid10912242"/> and fish.<ref name="pmid16387744">{{cite journal | vauthors = Heiden TK, Carvan MJ, Hutz RJ | title = Inhibition of follicular development, vitellogenesis, and serum 17beta-estradiol concentrations in zebrafish following chronic, sublethal dietary exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin | journal = Toxicol Sci | volume = 90 | issue = 2 | pages = 490–9 | date = April 2006 | pmid = 16387744 | doi = 10.1093/toxsci/kfj085 | doi-access=free }}</ref>
*Immunosuppression

:In rodents<ref name="pmid10502532">{{cite journal | vauthors = Holladay SD | title = Prenatal immunotoxicant exposure and postnatal autoimmune disease | journal = Environ Health Perspect | volume = 107 | issue = Suppl 5| pages = 687–91 | date = October 1999 | pmid = 10502532 | pmc = 1566248 | doi = 10.1289/ehp.99107s5687 | jstor = 3434328}}</ref> and fish.<ref name="pmid3765346">{{cite journal | vauthors = Spitsbergen JM, Schat KA, Kleeman JM, Peterson RE | title = Interactions of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) with immune responses of rainbow trout | journal = Vet Immunol Immunopathol | volume = 12 | issue = 1–4 | pages = 263–80 | date = June 1986 | pmid = 3765346 | doi = 10.1016/0165-2427(86)90130-3 }}</ref>

The LD50 of dioxin also varies wildly between species with the most notable disparity being between the ostensibly similar species of hamster and guinea pig. The oral LD50 for guinea pigs is as low as 0.5 to 2 μg/kg body weight, whereas the oral LD50 for hamsters can be as high as 1 to 5&nbsp;mg/kg body weight, a difference of as much as thousandfold or more, and even among rat strains there may be thousandfold differences.<ref name=Pohjanvirta/>