Microplastics: Considerations for Health in SLO County

Microplastics are plastic pieces less than five millimeters long. Microplastics are everywhere on the planet. They do not go away; rather, they break down into smaller and smaller particles, which can increase harm. Microplastics can come from a variety of sources, including larger plastics pieces that have broken apart (e.g., food packaging, etc.), building and construction materials, microfibers from textiles, tire wear particles, paint, pellets  used for plastic manufacturing, or microbeads used in personal care products. People can be exposed to microplastics in a variety of ways, such as through food, drinks, or inhaling airborne particles. The majority of people tested have been found to have microplastics in their body, with contamination in nearly every part of the body, including blood, breast milk, placentas, and even the brain. 

While we are still learning about the effects of microplastics on human health, including the concentration (or "dose") at which these effects are seen, research is clear that microplastics have harmful effects on animals. The sections below summarize possible human health effects and steps you can take to reduce your body's exposure to microplastics.

Health Impacts of Microplastics

There is not a lot of solid science yet on the human health effects of microplastics, but data is rapidly evolving as more studies are undertaken. This following list summarizes many of the likely negative health impacts in humans based on emerging research.

Researchers have observed effects of microplastics on human health in the areas of endocrine disruption, reproductive systems (male and female), inflammation, cell death, and virus and bacteria adherence. Research is additionally underway on possible effects related to dementia, lung cancer, liver function, and lipid metabolism. Researchers are also working to understand the level of exposure at which these effects may be seen. 

Medical research on the human health effects of microplastics includes: 

Reducing Your Body's Exposure to Microplastics

While we can be exposed to microplastics in many parts of our daily lives, there are steps we can take to reduce our exposure. One principle to keep in mind is that ingesting food and drinks from plastic containers, especially when the containers are exposed to heat (such as microwaving) can expose us to significant levels of microplastics.

  • Start by replacing just one or two single-use plastics and build from there. As you reduce plastic use, you will likely find you need to do some things a little differently and there will be come inconvenience at first. That is expected and you may need to experiment to find what works for you. Every time you choose a healthy alternative, you are reducing your body's exposure to microplastic. 
  • Instead of water from plastic bottles, drink tap water. Water bottled in plastic is a leading source of microplastic consumption in the U.S. Bottled water (in plastic bottles) also contributes to the plastic pollution issue, costs more than tap water, and can expose you to harmful endocrine-disrupting chemicals such as phthalates. While microplastics have also been found in tap water at varying levels, the overall impact of tap water remains lower than that of bottled water.
  • If you microwave food, do so in glass instead of plastic dishes. Microwaving food in plastic containers can pull large amounts of microplastics into the food.
  • Use metal, wood, or glass for cooking, food prep, eating/drinking, and storage. This includes avoiding plastic cutting boards. This helps prevent microplastics from entering your food as your prepare, consume, and store it.
  • Avoid paper coffee cups. These are coated in polyethylene. It is better to bring your own cup or bottle. 
  • Instead of synthetic textiles, use materials made from natural fibers such as cotton and wool. This includes clothing, upholstery, carpets, and rugs.
  • Use plastic-free options for hand soap, dish soap, and laundry detergent. This helps reduce exposure to microplastics in your household.
  • Use canvas or cotton mesh bags when shopping for food and other goods. This lessens exposure to you and your family as well as the environment.
  • Lessen inhalation of microplastics. Use indoor air filters and consider the use of N95 masks when cleaning the dryer lint filter.

You can find more, detailed information and scientific data regarding microplastics and synthetic food packaging from the Food Packaging Forum website.

Microplastics and the Natural Environment 

In addition to the health impacts discussed here, microplastics are known to cause harm to animals and our natural environment. The information here is specific to the human health impacts of microplastics and steps we can take to reduce our own consumption of them. For more information on the broader environmental impact and steps you can take to reduce your overall plastic use, see this overview from the journal Science.