"All About" Series

All About Environmental Toxins

by Brian St. Pierre

Environmental toxins are cancer-causing chemicals and endocrine disruptors, both human-made and naturally occurring, that can harm our health by disrupting sensitive biological systems.

Here, we review what endocrine disruptors are, where they come from, and how to minimize exposure to help protect you and your family from their potentially dangerous effects.

What are environmental toxins?

Environmental toxins include naturally occurring compounds such as:

  • lead;
  • mercury;
  • radon;
  • formaldehyde;
  • benzene; and
  • cadmium.

They also include human-made chemicals like:

  • BPA;
  • phthalates; and
  • pesticides.

In toxic doses, all of these compounds can negatively affect human health.  Many of them are known to:

  • cause cancer (radon, formaldehyde, benzene);
  • act as endocrine disruptors (BPA, pesticides, phthalates); and
  • cause organ failure or developmental problems (lead, mercury, cadmium)

Lead toxicity is a well-known example. People are generally aware of potential sources of lead, such as old paint and old pipes.

Cadmium toxicity was first realized in the 50s and 60s, and policies now limit industrial exposure.

Mercury is also a well-known toxin. To learn more about its effects check out All About Nutrition and Mercury Toxicity.

While these three environmental toxins are well-known, this article will focus on the compounds that are ubiquitous in our environment, but aren’t as well regulated.  It will also suggest ways you can decrease your exposure to them.

Endocrine disruptors

Endocrine disruptors include a wide range of substances, both natural and human-made, that may interfere with the body’s endocrine (hormone and cell signaling) system and produce adverse developmental, reproductive, neurological, and immune effects.

endocrine disruptor graphic All About Environmental Toxins
Action of endocrine disruptors

Endocrine disruptors usually mimic estrogen and are found in many everyday products we use, including:

  • some plastic bottles and containers;
  • food can liners;
  • detergents;
  • flame retardants;
  • toys;
  • cosmetics; and
  • pesticides.

In particular, the industrially produced compounds bisphenol A (BPA), pesticides, and phthalates are among the most potentially dangerous.

Research shows that endocrine disruptors may pose the greatest risk during prenatal and early postnatal development when organ and neural systems are forming. Pregnant or breast-feeding women, or women planning on becoming pregnant, should be the most cautious.

BPA: What is it, where is it, and how do I get less of it?

Much of the concern about endocrine disruptors has focused on BPA, a compound that is widely used in the manufacture of polycarbonate plastics and epoxy resins that are used in food and drink packaging, water and baby bottles, metal can linings, bottle tops, and water supply pipes. In addition, BPA can also be found in thermal paper receipts, though the amount of exposure from these particular products is thought to be minimal.

Low-dose exposure to BPA may produce a wide variety of physiological problems, including:

  • obesity;
  • infertility;
  • aggressive behavior;
  • early onset of puberty;
  • hormone-dependent cancers such as prostate and breast cancer; and
  • lower testosterone levels and sperm production.

BPA exposure occurs when the chemical leaches out from the product into food and water, especially when plastic containers are washed, heated or stressed. The highest estimated daily intakes of BPA occur in infants and children.

In fact 93% of children 6 years of age and older have detectable levels of BPA in their urine, and a 2011 study found that 96% of American women also have detectable levels. In September 2010, Canada became the first country to declare BPA a toxic substance; the European Union and Canada now ban BPA in baby bottles.

The good news is that BPA exits the body quickly. A 2011 study found that when participants ate their usual diets, followed by three days of consuming foods that were not canned or packaged, BPA levels in their urine decreased by 66%.

To reduce exposure to BPA:

  • Minimize use of plastic containers with the #7 or #3 on the bottom.
  • Don’t microwave plastic food containers, and don’t wash them in the dishwasher or with harsh detergents.
  • Reduce use of canned foods and eat mostly fresh or frozen foods.
  • When possible opt for glass, porcelain or stainless steel cups, containers, water bottles and travel mugs.
  • Use baby bottles that are BPA free (or better yet use glass bottles) and look for toys labeled BPA free.

Pesticides: What are they, where are they, and how do I reduce my exposure?

Pesticides are any substance used to kill, repel, or control certain forms of plant or animal life that are deemed pests. This includes herbicides, insecticides, fungicides, disinfectants, and compounds used to control rodents. In the US, over 4.5 billion pounds of pesticides are used each year.

Most conventional food production uses pesticides, so people are exposed to low levels of pesticide residues through their diets. While the health effects of pesticide residues are not entirely clear, research from the National Institute of Health showed that farmers who use agricultural insecticides experience an increase in headaches, fatigue, insomnia, dizziness, hand tremors, and other neurological symptoms, while licensed pesticide applicators have a 20-200% increased risk of developing diabetes.

Other data found that individuals reporting regular exposure to pesticides had a 70% higher incidence of Parkinson’s disease than those reporting no exposure.

It also appears that children are particularly susceptible to adverse effects from exposure to pesticides, specifically neuro-developmental problems. This is probably because children eat more food relative to their size. They also play in the dirt and spend time on the ground, where pesticides may linger.

To reduce exposure to pesticides:

  • Wash and scrub all fruits and vegetables, organic or conventional.
  • If possible purchase mostly organic fruits and vegetables, particularly the ones consistently found to have the highest pesticide residues – apples, strawberries, celery, peaches and spinach. Check out the Environmental Working Group’s Dirty Dozen and Clean 15 for more info.
  • Grow your own!

Phthalates: What are they, where are they, and how do I reduce my exposure?

Phthalates are chemicals used to soften plastics. They are found in a wide variety of products, including bottles, shampoo, cosmetics, lotions, nail polish, and deodorant. At one time most flexible plastics contained high levels of phthalates. Fortunately, they are being phased out in the US and Europe due to emerging recognition of their risks.

The National Institute of Environmental Health Sciences (NIEHS), part of the National Institute of Health, has found that pre-natal exposure to phthalates is associated with adverse genital development and can significantly reduce masculine behavior in boys. Women with high exposure to phthalates while pregnant report significantly more disruptive behavior in their children, while other research by NIEHS has found phthalate exposure can lead to thyroid dysfunction in adults.

Fortunately, as with BPA, if exposure is decreased, phthalates quickly exit the body. The same study that found a large decrease in BPA levels a mere three days after participants stopped eating canned and packaged foods also found that phthalate levels in the urine decreased by 53-56% during the same time period.

To reduce phthalate exposure:

  • Minimize use of plastics with the recycling code #3.
  • Use PVC-free containers. Buy plastic wrap and bags made from polyethylene and use glass containers. If you do use plastic containers, do not heat or microwave them.
  • Choose phthalate-free toys. Many large toymakers have pledged to stop using phthalates, but be sure to look for toys made from polypropylene or polyethylene.
  • Purchase phthalate-free beauty products. Avoid nail polish, perfumes, colognes, and other scented products that list phthalates as an ingredient. Many scented products simply list “fragrance” as an ingredient, which often incorporates a number of different chemicals including phthalates. Try to minimize these products, or for more information on phthalate-free cosmetics and personal care products, visit the National Campaign for Safe Cosmetics and the Environmental Working Group, which maintains a database on cosmetic products and their ingredients.

Carcinogens

Hundreds of chemicals are capable of inducing cancer in humans or animals after prolonged or excessive exposure. Chemically-induced cancer generally develops many years after exposure to a toxic agent. For example, mesothelioma (a form of lung cancer) may take 30 years to emerge after asbestos exposure.

In 2010, the U.S. President’s Cancer Panel Report declared:

“The true burden of environmentally induced cancers has been grossly underestimated… this group of carcinogens has not been addressed adequately by the National Cancer Program. The American people – even before they are born – are bombarded continually with myriad combinations of these dangerous exposures.”

According to the report there are about 80,000 chemicals in commercial use in the United States, but only about 2% of those have been assessed for their safety.

The Cancer Panel report singles out radon, formaldehyde, and benzene as major environmental toxins that are causing cancer.

Radon: What is it, where is it, and how do I get less of it?

Radon is a colorless, odorless radioactive gas. It comes from the natural decay of uranium or thorium found in nearly all soils and it typically moves up through the ground and into the home through cracks in floors, walls, and foundations.

radon 300x267 All About Environmental Toxins
Radon movement from ground to home.

It can also be released from building materials or from well water. Radon breaks down quickly, giving off radioactive particles. Long-term exposure to these particles can lead to lung cancer.

The U.S. Environmental Protection Agency estimates that radon causes about 21,000 lung cancer deaths in the United States each year, with 1 in 20 US homes having elevated levels. Radon exposure is the second leading cause of lung cancer after smoking and the leading cause among non-smokers.

Many radon-related lung cancer deaths can be prevented by testing for radon and taking the necessary steps to lower radon levels in homes that have elevated radon. This process is known as radon mitigation.

To reduce radon exposure:

  • Get your home air checked. It is simple and inexpensive.
  • If you use a well, check your water also.

Formaldehyde: What is it, where is it, and how do I get less of it?

Formaldehyde is a colourless, flammable, strong-smelling chemical that is used in building materials and in the manufacture of many household products. It also occurs naturally in the environment and is produced in small amounts by most living organisms as part of normal metabolic processes. Several government agencies have classified formaldehyde as a known human carcinogen.

Formaldehyde sources in the home include pressed-wood products such as particleboard and plywood, glues and adhesives, permanent press fabrics, cigarette smoke, and fuel-burning appliances. In addition, formaldehyde is commonly used as an industrial fungicide, germicide, and disinfectant, and as a preservative in mortuaries and medical laboratories.

Research studies of workers exposed to formaldehyde have suggested an association between formaldehyde exposure and several cancers, including nasopharyngeal cancer and leukemia. Rats exposed to formaldehyde fumes developed nasal cancer.

To reduce formaldehyde exposure:

  • Use “exterior-grade” pressed-wood products to limit formaldehyde exposure in the home.
  • Ensure adequate ventilation and moderate temperatures.
  • Reduce humidity levels with air conditioners and dehumidifiers.
  • Go natural and grow plants in your home.

Benzene: What is it, where is it, and how do I get less of it?

Benzene is a colourless liquid that evaporates quickly. It is naturally found in crude oil and is a basic petrochemical. Unfortunately, it is also a known human carcinogen.

Benzene is found in tobacco smoke, gasoline (and therefore car exhaust), pesticides, synthetic fibres, plastics, inks, oils, and detergents. Benzene has also been found in dryer emissions from scented laundry detergent and dryer sheets, and in soft drinks, although these have since been reformulated to exclude it.

About 50% of the benzene exposure in the US results from smoking tobacco or from second-hand smoke.

Substantial amounts of data link benzene to aplastic anemia, bone marrow abnormalities, and leukemia — particularly acute myeloid leukemia (AML) and acute non-lymphocytic leukemia (ANLL).

To reduce benzene exposure:

  • Don’t smoke and try to avoid second hand smoke.
  • Ensure adequate ventilation in your home.
  • Use non-scented laundry detergents.
  • Keep plants in the home.

Conclusions

Environmental toxins can cause serious health effects when exposure is allowed to accumulate, but it is important to remember that the poison is in the dose. Problems usually result from prolonged or excessive exposure; the occasional use of a plastic cup probably won’t hurt you!

While it is impossible to completely eliminate exposure (and it might drive you crazy to try!), a few simple steps will go a long way towards protecting you and your family:

  • Decrease use of plastic – transition to glass, stainless steel and porcelain containers, glasses and mugs.
  • Wash all produce, and if possible purchase organic options from the Dirty Dozen.
  • Use fewer products with the term “fragrance.”
  • Get your home air and water checked for radon.
  • Don’t smoke.
  • Keep plenty of plants in the home.

There’s no need to freak out over occasional exposure to environmental toxins. Just look for simple ways to reduce your everyday exposure. Make changes slowly, one at a time, in a manageable way, and you will decrease your risk with minimal stress.

References

Click here to view the information sources referenced in this article.

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