Microplastics found in the Atlantic Ocean near the Azores. Photo via Wikimedia Commons

You’re likely taking in tiny particles of plastic every time you eat, drink and breathe, according to research into the risks to human health from the buildup of plastic debris in the environment. Although scientists haven’t yet delineated the specific harms, there’s reason enough to worry.

Microplastics result from the breakdown into ever smaller bits of everyday plastic discards, like packaging, children’s toys, and synthetic clothing and carpeting. Despite their small dimension (sometimes invisible), microplastics are still made of long-chain polymer molecules that make plastics resistant to bio-degradation.

Consequently, microplastics (both micro-particulates and microfibers) are ubiquitous now in aquatic and terrestrial ecosystems worldwide, and there’s little mystery as to why.

Since the dawn of the Age of Plastics around 1950, humans have enjoyed a love affair with single-use disposables and basically anything that can be formed from cheap polymer feed stocks. In 2018, worldwide plastics production had risen to 359 million metric tons, tripling since just 1990.

But despite encouraging signs that people are starting to worry about plastic pollution – over 120 countries have banned plastic bags – global plastics production is still rising.

As of 2015, 60 percent of all plastics ever produced had accumulated in landfills or, courtesy of human negligence, the environment. Microplastics are building up in farmland soils, lakes, oceans, and the air we breathe. Accumulation of microplastics is seen in environs as remote as the Arctic.

It should be no surprise that these tiny particles are showing up on our dinner plates and even in our poop.

To estimate ingestion of micropolastics by typical Americans, Canadian scientists reviewed available studies of these materials in drinking water, air and foods commonly consumed by Americans (seafood, honey, sugar and table salt). Data on other major food groups were not yet available.

Applying recommended U.S. dietary guidelines, it was estimated that, through diet alone, Americans likely ingest 39,000 to 52,000 microplastic particles annually. If exposure via inhalation is included, those estimates rise to 74,000 to 121,000. The most came from air, bottled water and seafood. Salt, tap water and beer contributed the least.

Importantly, these figures underestimate the total intake, given that microplastics in meat, dairy, vegetables and grains remain unstudied and a separate finding suggests the greatest mealtime consumption stems from airborne microfibers raining down onto our meals.

Are Microplastics Dangerous?

Large or small, plastics are carriers of dangerous chemicals either manufactured into them or adsorbed from the surroundings because of their surface affinity for certain environmental toxins. The smaller the plastic particle, the greater the surface area-to-volume ratio and capacity to attract toxic chemicals.

Many substances within or on plastics are known endocrine disruptors, carcinogens or mutagens. Once microplastics enter the food chain through uptake by creatures closer to the base, there’s potential for associated chemicals to concentrate up the chain, compounding the risks to top tier eaters like humans.

Of equal concern are health threats from inhaled microplastics, due to both tissue reactions to foreign particles and the leaching out of toxins. Research reveals these particles can embed in the lungs and trigger inflammatory tissue responses possibly associated with conditions like asthma, interstitial lung disease, and even cancer.

Moreover, there’s evidence that microplastics in our tissues can translocate to the circulatory or lymphatic system and reach other organs. The tinier the particle, the greater the risk of translocation. Crossings into human breast milk and fetal circulation have also been documented.

Is Avoiding Microplastics Possible?

Given that few food groups have been tested for microplastics, it’s unclear how personal exposure might be reduced via dietary choices, though the Canadian study found 23 times as many microplastics in bottled compared to tap water.

Because air outdoors has fewer microplastics than indoor air, maintaining a well-ventilated home might reduce exposure. Frequent vacuuming of carpeting, replacing vinyl flooring and synthetic carpeting with hardwood and tile, and avoiding clothing and upholstery made of synthetic fibers should also.

And, home air and water filtration systems are readily available that promise elimination of these particles.

However, the biggest impact you can have on global microplastics pollution is to say no to single-use plastics and pressure state and federal representatives to craft policies that, at all stages in the life-cycle of plastics, stem their flow into the environment.

Sarah Mosko is a licensed psychologist, sleep disorders specialist, and freelance environmental writer who grew up in San Diego but currently lives in Orange County.

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