Ask the doctors: How do microplastics affect your health?
Q: The more I read about microplastics, the more I want to do something to lower my family's exposure to them. Any thoughts? Also, what is so much worse about microplastics than dust or pollen?
A: For those who are not familiar, the term “microplastics” refers to tiny particles of plastic that range in size from smaller than a grain of sand to microscopic.
Some of these particles are added to a wide range of products to act as thickeners or exfoliants, or to add structure and texture. However, the majority enter the environment when products made with plastic undergo wear and tear.
It is estimated that between 10 and 40 metric tons of these minuscule pollutants are released into the environment each year. Researchers have found microplastics in fresh snowfall in Antarctica, in the cloud vapor around Mt. Everest and in the Mariana Trench — the deepest region of the ocean we know. They have even been found in meconium, which is the first bowel movement of a newborn infant.
Unlike natural materials, plastics do not decompose or degrade. Instead, they split, break, shatter and then crumble into ever-smaller particles. These particles become small enough to be swallowed, inhaled or absorbed through the skin.
They are also able to penetrate cell membranes, enter the bloodstream and even cross the blood-brain barrier. This is due to their chemical properties and their minute size — often mere nanometers — which is far smaller than the dust and pollen you asked about.
The chemicals contained in microplastics have been shown to accumulate in bodily tissues. This can lead to bioactive effects, including causing inflammation, changing hormone interactions, altering immune response, disrupting the gut microbiome and causing physical damage. Microplastics also easily bond to heavy metals, endocrine disruptors and so-called forever chemicals, and they can carry them into the body.
To start reducing the microplastics around you, avoid single-use water bottles and food containers. They not only shed microplastics into their contents, but they also become a major source of environmental pollutants when discarded. Even to-go cups in coffee shops are lined with plastic, so bringing a non-plastic cup can reduce that exposure.
Many of us rely on plastic bags and wraps for food storage; however, these also transfer microplastics into their contents. And don't use plastic wrap in the microwave, as this causes chemicals to leach out.
You might consider investing in a good water filter, and in stainless steel or microwave-safe glass containers for food storage. Speaking of food, you'll find fewer microplastics in fresh and unprocessed foods and in those that sit lower on the food chain.
Even our clothes — many of which contain synthetic fabrics — shed microplastics when we wear them and when we wash them. Opt for natural fabrics when shopping, like cotton, linen and wool.
The United States Environmental Protection Agency, epa.gov/saferchoice, is a good resource for guidance about products that are free of microplastics. And remember, as with any change, it's easiest to undertake in increments.
If any readers have suggestions, let us know. We would love to hear and to share them.
• Dr. Eve Glazier is an internist and associate professor of medicine at UCLA Health. Dr. Elizabeth Ko is an internist and assistant professor of medicine at UCLA Health. Send your questions to askthedoctors@mednet.ucla.edu.
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