What are microplastics?
Microplastics are small pieces of plastic, less than 5mm in length. Nanoplastics, a subcategory of microplastics, are even smaller: less than a micron and invisible to the human eye. Primary microplastics are those intentionally manufactured in the small size range for commercial uses, like glitter or those tiny beads in an exfoliating face wash . Secondary microplastics are formed when larger pieces break down after being exposed to the elements—like waves, wind, or sunlight—for an extended period of time.
Which foods contain microplastics?
A few years ago, as microplastics began turning up in the guts of fish and shellfish, the concern was focused on the safety of seafood. Shellfish were a particular worry, because in their case, unlike fish, we eat the entire animal—stomach, microplastics and all. In 2017, Belgian scientists announced that seafood lovers could consume up to 11,000 plastic particles a year by eating mussels, a favorite dish in that country.
Other studies have found microplastics in beer, wines with polyethylene stoppers, rice, table salts, and honey. Microplastics can even be found in fruits and vegetables, like apples, broccoli, and carrots with plants able to absorb nanoplastics through their root systems. And plastic tea bags are leaching billions of particles every time you make a cup of Earl Gray.
Likewise, anything that has been packaged in plastic is going to have plastic in it. And it’s almost impossible to eat a meal without ingesting particulate matter. There’s plastic in the air which can potentially settle on everything it comes in contact with.
What risks does this pose to human health?
Various studies back this up. Inhaling airborne microplastic has been shown to cause respiratory inflammation in some people. Research on fish who ingested microplastics found evidence of neurotoxicity (chemical- or substance-induced alterations to the nervous system) and oxidative damage (cell and tissue damage caused by an imbalance of free radicals and antioxidants in the body). A 2020 study on male mice also discovered that ingesting microplastics can affect reproduction, and microplastics are known to contain endocrine-disrupting chemicals, which can interfere with the body's hormones and potentially lead to brain, immune, and other health problems.
Microplastics have also been identified as toxicological vectors. This means the particles can adsorb additional chemicals on their surfaces before coming in contact with a human cell. Various organic materials and heavy metals collected in the life of a microplastic can increase its toxicity to the humans and animals which might ingest it.
What can we reduce microplastics pollution?
Avoid foods packaged in plastic. Reusable totes and produce bags can replace plastic options at the supermarket. Grocery staples like peanut butter and yogurt typically have plastic-free alternatives, albeit pricier ones. Go loose leaf instead of using tea bags. Also, ditch bottled water, our largest source of dietary microplastic, and bring your own water bottle whenever possible. Then, bit by bit, try to eliminate household plastics, like shampoo bottles and bubble wrap. Every piece of microplastic that settles on our meals, contaminates our water, or lodges itself inside our apples ultimately came from people. And so if we’re cutting down our general usage of it, that impacts everything.
Organizations such as the United Nations Expert Panel of the United Nations Environmental Program engaged more than 100 countries in educational campaigns aimed at raising awareness of plastics pollution and encouraging reuse and recycling of plastics. Other international cooperative programs were established to address marine wastes, including microplastics pollution. In 2015 the United States passed the Microbead-Free Waters Act, which prohibits the manufacture and distribution of rinse-off cosmetics products that contain plastic microbeads. Many other countries also placed bans on microbeads.
Remediation of microplastics already in the environment is another key component of reducing microplastics pollution. Strategies under investigation included the use of microorganisms capable of breaking down synthetic microplastic polymers. A number of bacterial and fungal species possess biodegradation capabilities, breaking down chemicals such as polystyrene, polyester polyurethane, and polyethylene. Such microorganisms potentially can be applied to sewage wastewater and other contaminated environments.