Endocrine disruptors

Endocrine disruptors (from the Greek endo: inside, krinein: to excrete, and Latin disrumpere: to bring to a standstill), also known as xenohormones or endocrine disruptors, are substances which, once absorbed into the organism, even in small quantities, can have negative effects on the functions and development of the affected organism by altering its endocrine balance.

EDCs are mainly used in synthetically produced materials such as pesticides, solvents, plastic bottles, plastic toys. Some endocrine disrupting substances are specifically used in medicine (e.g. ovulation inhibitors).

WHO and UNEP have published a list of substances with proven or potential endocrine disrupting effects:

• Persistent and bioaccumulating halides: Persistent organic pollutants (e.g. Polychlorinated dibenzodioxins and dibenzofurans, polychlorinated biphenyls, hexachlorobenzene, perfluorooctane sulfonate, polybrominated diphenyl ethers, polybrominated biphenyls, chlordane, mirex, toxaphene, dichlorodiphenyltrichloroethane, lindane, endosulfane); other persistent and bioaccumulative substances (e.g. e.g. hexabromocyclododecane, chlorinated paraffins, perfluorinated carboxylic acids, octachlorostyrene)
• less persistent and less bioaccumulative substances: plasticisers and additives (e.g. phthalic esters, triphenyl phosphate, diethylhexyl adipate, butylbenzenes, triclocarbane, butylhydroxyanisole); polycyclic aromatic hydrocarbons (e.g. benzopyrenes, benz[a]anthracene, pyrene, anthracene); halophenols (e.g. (e.g. 2,4-dichlorophenol, pentachlorophenol, hydroxy-PCB, hydroxy-PBDE, tetrabromobisphenol A, 2,4,6-tribromophenol, triclosan); non-halophenols (e.g. bisphenol A, bisphenol F, bisphenol S, nonylphenol, octylphenol, resorcinol); pesticides, pharmaceuticals and cosmetics: plant protection products currently used (e.g. e.g. 2,4-dichlorophenoxyacetic acid, atrazine, carbaryl, malathion, mancozeb, vinclozolin, prochloraz, procymidone, chlorpyrifos, fenitrothion, linuron); pharmaceuticals, growth hormones and cosmetics (e.g. diethylstilbestrol, ethinylestradiol, tamoxifen, levonorgestrel, fluoxetine, flutamide, 4-methylbenzylidene camphor, octylmethoxycinnamate, parabens, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, galaxolide, 3-benzylidene camphor)
• Other chemicals: Metals and organometals (e.g. arsenic, cadmium, lead, mercury, methylmercury, tributyltin hydride, triphenyltin); natural hormones (e.g. 17-beta-estradiol, estrone, testosterone); phytoestrogens (e.g. isoflavones, coumestan, mycotoxins, prenylflavonoids)

Endocrine disruptors are groups of different chemicals. Chemically, these are mainly organochlorine compounds (pesticides such as DDT and metabolites), polychlorinated biphenyls (PCBs), polybrominated biphenyl ethers (flame retardants) or cosmetics such as synthetic perfumes, preservatives and UV filters. EDCs can also be of natural origin, e.g. phytoestrogens such as isoflavones, coumestan, different types of phytoestrogens, etc. mycotoxins, prenylflavonoids.

Endocrine disruptors interact either directly with hormone receptors or via epigenetic and cell cycle regulatory mechanisms. They influence breast development, breast and prostate carcinomas, neuroendocrine, thyroid metabolic functions and obesity (Diamanti-Kandarakis E et al. 2009). For diabetes mellitus there are numerous studies on EDCs and diabetes risk with regard to possible effects. Overall, there are clear indications of a relationship between exposure to dichlorodiphenyl dichloroethylene (p, p'-DDE), a metabolite of the pesticide dichlorodiphenyltrichloroethane, and the development of diabetes (Lind PM et al. 2018).

Regulation EC 1907/2006 concerning the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) stipulates that substances with endocrine disrupting properties can be identified as substances of very high concern and declared subject to authorisation.

1. Diamanti-Kandarakis E et al (2009) Endocrine-disrupting chemicals: an Endocrine Society scientific statement. Endocr Rev 30:293-342.
2. DiNardo JC et al (2018) Dermatological and environmental toxicological impact of the sunscreen ingredient oxybenzone/benzophenone-3 J Cosmet Dermatol 17:15-19.
3. Gore AC 2016). Endocrine Disrupting Chemicals. JAMA Intern Med 176:1705-1706.
4. Lind PM et al (2018) Endocrine-disrupting chemicals and risk of diabetes: an evidence-based review. Diabetologia 61:1495-1502.
5. Schug TT et al (2011) Endocrine disrupting chemicals and disease susceptibility. J Steroid Biochem Mol Biol 127:204-215.
6. Sifakis S et al (2017) Human exposure to endocrine disrupting chemicals: effects on the male and female reproductive systems. Environ Toxicol Pharmacol 51:56-70.