[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › Persistent environmental pollutants and endocrine disruptors # Persistent environmental pollutants and endocrine disruptors Chemicals such as PCBs, dioxins, PFAS, BPA and phthalates that stay in the body and the environment and can disturb hormones and immunity. Updated Nov 12, 2026 Some chemicals resist breakdown, dissolve in fat and build up through food chains, so small, long exposures add up. Others, even if short-lived, act on hormone receptors. This page covers halogenated pollutants (PCBs, PBBs, dioxins, PFAS), endocrine disruptors (DDT, phthalates, bisphenol A), immunotoxic chemicals, and other environmental and occupational hazards: cyanotoxins, asbestos, beryllium, cadmium and nanomaterials. ## Key points - Endocrine disruptors mimic, block or alter hormones; examples are DDT, PCBs, phthalates, bisphenol A, PFAS, some flame retardants and plant phytoestrogens. - Dioxins are mainly unintended by-products of burning and industry; most human exposure comes through fatty foods, and they stay in the body for years. - TCDD, the most potent dioxin, acts through the aryl hydrocarbon receptor (AhR); it is a strong immunosuppressant and a known human carcinogen. - PFAS are called forever chemicals: they barely degrade, accumulate in the body and have endocrine and emerging immune effects. - Asbestos of every type causes asbestosis, lung cancer and mesothelioma; smoking multiplies the lung cancer risk. - Beryllium inhaled at work causes a granulomatous lung disease; cadmium damages the lungs and kidneys; nanomaterials pose new and still poorly known hazards. ## PCBs, PBBs and dioxins Polychlorinated biphenyls (PCBs) were made in large amounts for electrical insulation and are now banned, but they persist. Mass poisonings from contaminated cooking oil in Japan (Yusho) and Taiwan (Yucheng) affected adults and the babies of exposed mothers, although the oil also contained related furans. Prenatal exposure through heavily contaminated fish has been linked to lower intellectual function in children. Polybrominated biphenyls and their ethers were used as flame retardants. Dioxins and furans are unwanted by-products of poorly controlled burning, waste incineration and some chemical manufacture; dioxin-like PCBs behave the same way. They are stable, fat-soluble and poorly metabolized, so more than 90% of human exposure comes from food such as meat, dairy and fish, and they remain in the body for years. High exposure causes chloracne; long exposure impairs immune, nervous, endocrine and reproductive development, with the fetus most sensitive. ## Endocrine disruptors - Definition: chemicals that interfere with hormone production or signalling, by binding hormone receptors (oestrogen, androgen, thyroid) or by changing how hormones are made and handled. - DDT and other organochlorines: persistent, oestrogen-like and stored in fat; banned in most countries but still used for malaria vector control in some. - Phthalates: plasticizers in PVC, medical tubing, cosmetics and food packaging; they cross the placenta, and exposure is linked to reduced semen quality, lower testosterone and shorter anogenital distance in boys. - Bisphenol A: used in polycarbonate plastics, can linings and bottle tops; it binds oestrogen receptors weakly and acts as a mixed agonist-antagonist; it is found in the urine of nearly everyone, and baby-bottle bans followed, though replacements are less studied. - Others: PFAS, polybrominated flame retardants, the herbicide atrazine, perchlorate and plant phytoestrogens. - Timing matters: effects are greatest during fetal life, infancy and puberty, and even low doses may act because hormones work at low concentrations. ## Immunotoxic chemicals Immunotoxic chemicals can suppress immunity, raising the risk of infection and poorer vaccine responses, or overactivate it, causing inflammation and autoimmunity. TCDD is the most potent immunotoxicant: through the AhR it pushes newly activated T cells toward a regulatory, suppressive phenotype and reduces antibody production. Fine particulate matter carries polycyclic aromatic hydrocarbons and dioxin-like PCBs that also activate the AhR, but in the lung this drives oxidative stress and inflammation rather than suppression. Emerging data also point to immunotoxic effects of PFAS. ## Perfluorinated compounds (PFAS) PFAS are chains of carbon fully or partly covered with fluorine. They repel water and grease, so they are used in firefighting foams, non-stick cookware, stain-resistant fabrics and food packaging. The carbon–fluorine bond is extremely stable, so these forever chemicals accumulate in water, soil, wildlife and people, mainly through food and drinking water; PFOA stays in the human body for years. Older long-chain PFAS have been phased out in some countries, but replacements with shorter chains keep appearing. ## Cyanotoxins and asbestos Cyanotoxins are peptides, alkaloids and lipopolysaccharides made by blue-green algae that bloom in warm lakes and reservoirs. In high amounts they can cause rapid death by respiratory failure; lower amounts cause gut, skin, liver and nervous system illness. All forms of asbestos, chrysotile included, cause progressive lung fibrosis (asbestosis), lung cancer and mesothelioma of the pleura or peritoneum, and lung cancer occurs at exposures below those that cause asbestosis. Smoking and asbestos together multiply the lung cancer risk. Colombia banned all asbestos from 2021 (see carcinogens and chemoprevention). ## Beryllium, cadmium and nanomaterials - Beryllium: a light metal in alloys, electronics, aerospace parts and dental appliances; inhaled dust causes acute and chronic beryllium disease, a granulomatous lung fibrosis driven by an immune reaction in sensitized workers; IARC lists beryllium as a known human carcinogen. - Cadmium: used in batteries, pigments, plating and soldering; heated cadmium releases fumes that cause metal fume fever, and long exposure causes lung fibrosis and severe kidney damage; it is also a known human carcinogen. - Nanomaterials: particles with at least one dimension at the nanometre scale, used in medicines, electronics and consumer goods; their small size lets them cross membranes and behave differently from the bulk material, and silica, silver and zinc oxide nanoparticles have shown toxicity in studies; their long-term human effects are still being studied. ## Memory aid The persistent pollutants are FAT: Fat-soluble, Accumulating up the food chain, and Taking years to leave the body. ## Test yourself Think of the answer, then tap the question to see it. ## Through which receptor does TCDD cause most of its toxicity? The aryl hydrocarbon receptor (AhR), a transcription factor present in most immune cells; TCDD activates it strongly and for a long time. ## How does most human exposure to dioxins happen? Through food, mainly fatty foods such as meat, dairy, fish and shellfish, because dioxins accumulate up the food chain. ## Why is bisphenol A described as an endocrine disruptor? Its shape resembles oestrogen, so it binds oestrogen receptors, acting partly as an agonist and partly as an antagonist. ## Why are PFAS called forever chemicals? Their carbon–fluorine bonds are so stable that they barely degrade in the environment or the body, so they keep accumulating. ## What lung disease does inhaled beryllium cause in sensitized workers? Chronic beryllium disease, a granulomatous lung fibrosis driven by an immune reaction, which progresses and has a poor outlook. [Add to my cards (5)](https://durgical.app/estudiar/?add=/en/pharmacology/topics/persistent-environmental-pollutants-and-endocrine-disruptors/) [More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology) ## Connections ## Related classes 1 - [Chelating agents](https://durgical.com/en/pharmacology/classes/chelating-agents/) [← All of pharmacology](https://durgical.com/en/pharmacology/) Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given. Sources: [Endocrine Disruptors](https://www.niehs.nih.gov/health/topics/agents/endocrine) (National Institute of Environmental Health Sciences, 2026); [Dioxins](https://www.who.int/news-room/fact-sheets/detail/dioxins-and-their-effects-on-human-health) (World Health Organization, 2026). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. 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