Environmental Contaminants that Affect Your Thyroid Health

Thyroid diseases and disorders in humans such as autoimmune thyroid disease have increased in incidence over the past several decades, the burden of thyroid disease now effects approximately two billion people worldwide.

Even slight decreases in thyroid function such as subclinical hypothyroidism can have a negative impact on cholesterol levels, weight, mood and energy levels to name a few. Both genetic along with environmental factors affect the health of the thyroid gland.

Environmental endocrine disruptors can play a significant negative role in the health of the thyroid. Studies show that even exposure during foetal development can impact the occurrence of thyroid disorders early and/or later in life and possibly in future generations.

There are many man-made chemicals that influence and negatively impact the production and function of thyroid hormones.
In 2009 the American Medical Association (AMA) called for the reduced exposure to environmental contaminants that cause known endocrine dysfunction and many other researching bodies have petitioned for the safety of chemicals to be tested in a more thorough manner before use.

An interesting point in this article published in the Journal Endocrine Review that was made by some researchers, arguing against the dogma that ‘the dose makes the poison’, simply put, some endocrine disrupting chemicals don’t have to be in large amounts to cause a negative effect, even very small doses can have a significant negative effect and people are often exposed chronically to these types of chemicals daily in smaller doses.

Many people are of the belief that chemical exposure at low doses is harmless, often it’s the consistent exposure in small amounts that tends to degrade and destroy tissue and cell health over the longer term.

Many environmental compounds, particularly chemicals associated with plastics, industry and pesticides including polychlorinated biphenyls (PCBs), polybrominated diphenylethers (PBDEs), bisphenol-A (BPA) and triclosan, may have a direct negative impact on thyroid function and health, but these effects are complex and are not completely understood.

Organochlorine pesticides and dioxins may decrease serum T4 (thyroxine) half-life by activating hepatic enzymes.

There is also emerging evidence that phthalates, brominated flame retardants and perfluorinated chemicals may have thyroid disrupting properties.


Phthalates found in some plastics have been shown to decrease thyroid function and changes in the thyroid gland while Bisphenol A (BPA) decreases thyroid receptor site sensitivity, causing thyroid resistance. BPA chemicals are found in plastic drink bottles, plastic wraps, food containers, can linings and takeaway containers. Using glass and stainless steel where possible has many health benefits.


A major study found that perfluorooctanoic acid (PFOA), a chemical used to make teflon, and other non-stick products can affect thyroid function even at moderate levels of exposure. In a survey it has been found there is a strong association with higher PFOA exposure and thyroid disease.


This chemical is a by-product of jet and rocket fuel, car airbags and fireworks and has found its way into our environment. Most people test positive to this chemical in the body and it has been found in our drinking water and food supply. In one study it demonstrated that babies had abnormal thyroid function when their mothers were exposed to perchlorate contaminated water.

A CDC study, found that perchlorate exposure is affecting thyroid hormone levels in American women, particularly those with lower iodine intake. Perchlorates can lower levels of the thyroid hormones essential to proper development of fetuses, infants and good health in adults.


In one study published in the American Journal of Epidemiology, found women who were married to men using pesticides such as aldrin, DDT and lindane were at much higher risk of developing thyroid disease than women in non- agricultural areas.

Antifungals and other weed killers

Are associated with a decrease in thyroid function in farmers. In this small study the farmers exposed where more likely to have lowered thyroid function then the organic farmers.

Flame retardants

Flame retardants, (polybrominated diphenyl ethers (PBDEs)), have been found in several studies to disturb thyroid function. Flame-retardant chemicals are found in televisions, computer screens, furniture, rugs and carpeting.


An antibacterial agent used in soaps, toothpaste and anti-microbial products, exposure to low levels of triclosan disrupts thyroid hormone- associated gene expression and can alter thyroid function.

Bromine, chloride and fluoride

May inhibit iodine binding and hormonal release from the thyroid gland. Only small amounts have been found to negatively effect thyroid function particularly in association with lower iodine levels.

Heavy metals

Can also have a negative effect on the immune system and can increase the incidence of autoimmune activity. These include mercury, aluminium and lead.


Some medications can have an anti-thyroid action such as lithium, amiodarone, some antiepileptic medication such as phenytoin and carbamazepine, Interferons, Interleukins and radiation to the head or neck area can cause hypothyroidism up to 10years later. It is always best to talk to your doctor if you have any concerns.

What you can do

Here at reboot we always encourage our Rebooters to use natural cleaning products, natural skin care products and to reduce the exposure to any chemicals as much as possible. Supporting your health with juice, fruits and vegetables, a healthy diet and lifestyle helps to support the detoxification of these chemicals and can reduce their negative impact on your health. Being aware can help us make changes in our immediate environment and reduce our exposure where possible.

Here are some great articles on using natural products for skincare and cleaning.

How to Use Apple Cider Vinegar on a Daily Basis For loads of edible skin care recipes.

Skin care ingredients to avoid.

Using good water filters is important to reduce the exposure of some of these chemicals that can be found in tap water.