Water Quality | Toxic Chemicals We Consume Without Knowing It

Toxic Chemicals We Consume Without Knowing It

Akash Goel, MD, Feb 2023 

If the pandemic served as a window into our health, what it revealed was a US population that is not only sick but also seemingly only getting sicker. Life expectancy is falling precipitously. Three fourths of Americans are overweight or obese, half have diabetes or prediabetes, and a majority are metabolically unhealthy. Furthermore, the rates of allergic, inflammatory, and autoimmune diseases are rising at rates of 3%-9% per year in the West, far faster than the speed of genetic change in this population.

Of course, diet and lifestyle are major factors behind such trends, but a grossly underappreciated driver in what ails us is the role of environmental toxins and endocrine-disrupting chemicals. In years past, these factors have largely evaded the traditional Western medical establishment; however, mounting evidence now supports their significance in fertility, metabolic health, and cancer.

Although several industrial chemicals and toxins have been identified as carcinogens and have subsequently been regulated, many more remain persistent in the environment and continue to be freely used. It is therefore incumbent upon both the general public and clinicians to be knowledgeable about these exposures. Here, we review some of the most common exposures and the substantial health risks associated with them, along with some general guidance around best practices for how to minimize exposure.

Microplastics

"Microplastics" is a term used to describe small fragments or particles of plastic breakdown or microbeads from household or personal care products, measuring less than 5 mm in length.

Plastic waste is accumulating at alarming and devastating proportions — by 2050, it is estimated that by weight, there will be more plastic than fish in the oceans. That translates into hundreds of thousands of tons of microplastics and trillions of these particles in the seas. A recent study demonstrated that microplastics were present in the bloodstream in the majority of 22 otherwise healthy participants.

Since the 1950s, plastic exposure has been shown to promote tumorigenesis in animal studies, and in vitro studies have demonstrated the toxicity of microplastics at the cellular level. However, it is not well known whether the plastic itself is toxic or if it simply serves as a carrier for other environmental toxins to bioaccumulate.

According to Tasha Stoiber, a senior scientist at the Environmental Working Group (EWG), "Microplastics have been widely detected in fish and seafood, as well as other products like bottled water, beer, honey, and tap water." EWG states there are no formal advisories on fish consumption to avoid exposure to microplastics at the moment.

Pressure also is mounting for a ban on microbeads in personal care products.

Until such bans are put in place, it is advised to avoid single-use plastics, favor reusable tote bags for grocery shopping rather than plastic bags, and opt for loose leaf tea or paper tea bags rather than mesh-based alternatives.

Phthalates

Phthalates are chemicals used to make plastics soft and durable, as well as to bind fragrances. They are commonly found in household items such as vinyl (eg, flooring, shower curtains) and fragrances, air fresheners, and perfumes.

Link to full article: https://www.medscape.com/viewarticle/988444

Phthalates are known hormone-disrupting chemicals, exposure to which has been associated with abnormal sexual and brain development in children, as well as lower levels of testosterone in men. Exposures are thought to occur via inhalation, ingestion, and skin contact; however, fasting studies demonstrate that a majority of exposure is probably food related.

To avoid phthalate exposures, recommendations include avoiding polyvinyl chloride plastics (particularly food containers, plastic wrap, and children's toys), which is identifiable by the recycle code number 3, as well as air fresheners and fragranced products.

The EWG's Skin Deep database provides an important resource on phthalate-free personal care products.

Despite pressure from consumer advocacy groups, the US Food and Drug Administration has not yet banned phthalates in food packaging.

Bisphenol A (BPA)

BPA is a chemical additive used to make clear and hard polycarbonate plastics, as well as epoxy and thermal papers. BPA is one of the highest-volume chemicals, with roughly 6 billion pounds produced each year. BPA is traditionally found in many clear plastic bottles and sippy cups, as well as in the lining of canned foods.

Structurally, BPA acts as an estrogen mimetic and has been associated with cardiovascular disease, obesity, and male sexual dysfunction. Since 2012, BPA has been banned in sippy cups and baby bottles, but there is some debate as to whether its replacements (bisphenol S and bisphenol F) are any safer; they appear to have similar hormonal effects as BPA.

As with phthalates, the majority of ingestion is thought to be food related. BPA has been found in more than 90% of a representative study population in the United States.

Guidance advises avoiding polycarbonate plastics (identifiable with the recycling code number 7), as well as avoiding handling thermal papers such as tickets and receipts, if possible. Food and beverages should be stored in glass or stainless steel. If plastic must be used, opt for polycarbonate- and polyvinyl chloride–free plastics, and food and beverage should never be reheated in plastic containers or wrapping. Canned foods should ideally be avoided, particularly canned tunas and condensed soups. If canned products are bought, they should ideally be BPA free.

Dioxins and Polychlorinated Biphenyls (PCBs)

Dioxins are mainly the byproducts of industrial practices; they are released after incineration, trash burning, and fires. PCBs, which are somewhat structurally related to dioxins, were previously found in products such as flame retardants and coolants. Dioxins and PCBs are often grouped in the same category under the umbrella term "persistent organic pollutants" because they break down slowly and remain in the environment even after emissions have been curbed.

Tetrachlorodibenzodioxin, perhaps the best-known dioxin, is a known carcinogen. Dioxins also have been associated with a host of health implications in development, immunity, and reproductive and endocrine systems. Higher levels of PCB exposure have also been associated with an increased risk for mortality from cardiovascular disease.

Notably, dioxin emissions have been reduced by 90% since the 1980s, and the US Environmental Protection Agency (EPA) has banned the use of PCBs in industrial manufacturing since 1979. However, environmental dioxins and PCBs still enter the food chain and accumulate in fat.

The best ways to avoid exposures are through limiting meat, fish, and dairy consumption and trimming the skin and fat from meats. The level of dioxins and PCBs found in meat, eggs, fish, and dairy are approximately 5-10 times higher than they are in plant-based foods. Research has shown that farmed salmon is likely to be the most PCB-contaminated protein source in the US diet; however, newer forms of land-based and sustainable aquaculture probably avoid this exposure.

Pesticides

The growth of modern monoculture agriculture in the United States over the past century has coincided with a dramatic surge in the use of industrial pesticides. In fact, over 90% of the US population have pesticides in their urine and blood, regardless of where they live. Exposures are thought to be food related.

First appeared on Medscape. https://www.medscape.com/viewarticle/988444