Bisphenol A (BPA)
The oestrogenic properties of BPA were identified in the 1930s when researchers were looking to treat symptoms relating to menopause, menstruation, nausea in pregnancy and prevention of miscarriages. It wasn’t pursued for this use, but BPA’s plasticising properties were utilised, and by the 1950s it was used in epoxy resins for protective coatings, linings and adhesives, then later for making clear, hard polycarbonate plastic.
Its endocrine-disrupting properties arose as an issue for research scientists in the 1990s, where its action on water bottles and animals kept in polycarbonate cages, as well as contamination from laboratory equipment made from polycarbonate, was producing unexpected experimental effects.
Having established that the BPA in polycarbonate was the source of contamination, the observed oestrogenic effects were not surprising. But the fact it was leaching out of plastic in quantities that could cause significant effects was unexpected, and given its ubiquity in a variety of consumer goods, the implications were enormous.
Studies on animals and in vitro testing on human cells have associated BPA exposure with breast and prostate cancers, obesity, neurobehavioural problems and reproductive abnormalities. Because babies and young children are more vulnerable to its effects due to their development stage and rates of metabolism, products for this group have caused the most concern. BPA is more likely to leach from containers into food and beverages if the containers are heated or the contents are of an acidic nature, while harsh detergents can break down the plastics causing BPA to be released.
As such, it’s been banned or voluntarily withdrawn from use in baby bottles in Australia, Canada, the US, Turkey and some European and Asian countries, and banned for use in linings of jars and tins for food aimed at children under three in France and Sweden. An American BPA producer famously required customers to agree it wouldn’t be used in products aimed at children under three.
What you can do: While it’s difficult to know whether BPA is in tin or jar linings, you can avoid polycarbonate plastics used in water bottles and other food containers (a "7" in the recycling triangle means the plastic is polycarbonate or "other").
Some chemical sunscreens, including widely used octyl methoxycinnamate (also called OMC or ethylhexyl methoxy cinnamate), as well as 4-methylbenzylidene camphor (4-MBC) and benzophenone 3, have been found in some studies to have developmental and reproductive effects, as well as thyroid effects from OMC. They’re not just found in sunscreens, but also cosmetics with sun protection such as lip balm, make-up and moisturiser. Most studies look at the chemicals in isolation, whereas in reality there is often more than one chemical sunscreen used in a preparation, not to mention other potential endocrine disruptors such as parabens. The combined effects of these aren’t known.
What you can do: Choose sunscreens with physical blockers, such as zinc oxide or titanium dioxide.
Phthalates are common chemicals primarily used as plasticisers in manufacturing flexible vinyl plastic found in flooring, food wrap and medical devices. They are also found in cosmetics and personal care products, such as fragrances, lotions and nail polish, and pharmaceuticals where they’re used in coatings for timed-release pills. As such, we eat, breathe and absorb them through our skin. They have been linked with endometriosis and early puberty in girls, and reproductive organ abnormalities and reduced fertility in males. They can also act on the thyroid, and have been linked with obesity.
What you can do: Some of the dangerous phthalates have been banned in cosmetics and children’s toys in Europe, and toys in the US. Only one phthalate has been banned in Australian toys. As they’re often found in fragrances such as air fresheners, you can avoid perfumed personal care and household products.
Parabens are preservatives used in many cosmetic and personal care products and have been found to have oestrogenic effects. The larger the molecule, the greater the effect, with the smaller molecule parabens being the safest, including methyl paraben which is the most commonly used. The European Scientific Committee on Consumer Safety conducted a review of parabens in consumer goods, and determined that they didn’t pose a risk in the quantities permitted in such products. However the Danish government has banned the use of some of the larger-molecule parabens (propyl-, isopropyl-, butyl- and isobutyl-parabens) in products for children up to three years old as a precautionary measure, as children might be especially vulnerable to endocrine effects. This is of particular concern if products are used on broken skin, such as nappy rash.
What you can do: Check the ingredients list for propyl-, isopropyl-, butyl- and isobutyl-parabens.
Many pesticides are endocrine disruptors, including some that have been banned but persist in the environment, and those that have been banned in some countries but not Australia, and some still widely in use. These include DDT, endosulfan, synthetic pyrethroids and chlorpyrifos.
DDT has an oestrogenic effect, and although it has been banned in most countries for several decades, it persists in the environment and the food chain. It’s still used in some countries for mosquito control where observable short-term malaria deaths are a greater concern than potential longer-term endocrine effects.
Atrazine is a selective herbicide used on animal feed crops, sugar cane and forestry plantations, as well as canola resistant to such herbicides. Apart from food residues, it can also enter the water supply, and has been linked with neuroendocrine effects. Triazine tolerant canola is resistant to atrazine if sprayed with it – the weeds die but the canola doesn’t. The Australian regulatory authorities determined that it doesn’t pose a risk, but will continue to monitor research.
Glyphosate (the active ingredient in Roundup) is widely used throughout the world in agriculture, parks and home gardens, and has been linked with endocrine disruption effects related to growth, sexual development and reproduction. Various food crops (soy, canola, corn, cotton, sugar beet) have been genetically modified so they’re resistant to glyphosate.
What you can do: Wash all fruit and vegetables before eating them. Minimise purchase of imported fresh, canned or frozen produce from countries with dubious pesticide regulation. Buy GM-free to avoid plant foods (such as canola and soy) that are tolerant to pesticides.
Triclosan is an antibacterial compound found in soap, hand wash and toothpaste, as well as other consumer products such as cleaning cloths and cutting boards. It interferes with the thyroid hormone and is oestrogenic. The US Food and Drug Administration (FDA) is currently reviewing the safety of triclosan, pointing out that while it’s “not currently known to be hazardous to humans”, tests on mammals and other animals have shown hormonal effects that warrant further scientific and regulatory review. Additional concerns relate to the potential contribution to antibiotic resistance. The FDA also points out that there’s no evidence that it has any extra health benefits over soap and water. According to the precautionary principle, it may be better to avoid it.
What you can do: Use soap and water. Many “antibacterial” soaps and toothpastes in the supermarket contain triclosan (liquid soaps and toothpaste) and triclocarban (bar soaps), so check the label.
Resorcinol is used in hair dyes and topical treatments for acne, seborrhoeic dermatitis, eczema, psoriasis, corns and warts. It is also an antiseptic and disinfectant. Resorcinol is currently on the European Union’s Category 1 list of endocrine disruptors, and has been linked to thyroid disease when used in large quantities on broken skin over a long period of time.
What you can do: Look for hair dye that’s resorcinol-free, and don’t over-use products containing resorcinol on broken skin.
Perfluoroalkyl acids (PFOA)
Their resistance to solvents, acids and bases, as well as their non-stick, quality and heat resistance makes these chemicals highly useful in a variety of consumer products, including stain- and water-repellent coatings and treatments for textiles (such as furniture upholstery, carpets, weatherproof clothing – think Gore-Tex), coatings for non-stick cookware (Teflon) and paper fast-food wrappers/containers.
Components of the polymers, in particular PFOA, have been linked with thyroid disease. While the WHO/UN Environment Programme (UNEP) has listed PFOA as a potential obesogen (a substance which may lead to obesity), a panel of expert scientists established to look into the effects of PFOA on people working in and living near a production factory determined that while it is probably associated with increased blood cholesterol, there was no evidence of a link with obesity or metabolic syndrome.
What you can do: Look for PFOA-free, rather than Teflon, non-stick cookware. If you have Teflon cookware at home, use it at low temperatures, and if it’s peeling throw it away – you don’t want little bits in your food.
The Endocrine Society is an international organisation of professionals concerned with endocrinology research and clinical practice. Its members include clinicians, researchers, educators, industry professionals and health professionals. They have provided a comprehensive review of the science behind endocrine disruptors.
The WHO and United Nations Environment Programme’s report on EDCs was released in February 2013.
The Danish Ministry of the Environment has information and a consumer-friendly pamphlet (in English) for expectant women on how to avoid EDCs.