Rick Smith, PhD
Rick Smith, PhD, is the president of the Canadian Climate Institute, executive producer of the documentary Plastic People: The Hidden Crisis of Microplastics, and co-author of Slow Death by Rubber Duck and Toxin Toxout.
Microplastics are pieces of plastic that are smaller that 5 millimeters. They range from the width of a pencil eraser to a tiny particle. They’re found everywhere in the environment, from the highest mountain peak to the deepest ocean trench. They’re in every breath you take, every bite of food you eat, and every sip of water you drink. They’ve also been found in every organ where scientists have tried to detect them, including the heart, lungs, gut, and brain. Now, scientists are discovering that the microplastics in your body might be hurting your health. But there’s hope.
There are simple ways to reduce your personal exposure to microplastics and help reduce microplastics in the environment.
About 440 million tons (880 billion pounds) of plastic are manufactured every year. Production has doubled since 2000, with 50 percent of all plastic produced in the last 15 years. Only 9 percent of plastic is recycled: The rest ends up in the environment.
Over time, with sunlight, heat, and the action of waves (there are an estimated 200 million tons of plastic waste in the ocean), plastic litter is pounded into smaller and smaller pieces. Those pieces of plastic aren’t going anywhere anytime soon. Plastic is a tough, sturdy substance: Virtually every molecule of plastic ever made still exists somewhere on Earth.
There are endless sources of microplastics. They come from fabrics, with 64 percent of clothes made from synthetic, plastic-based materials like polyester, nylon, and acrylic. (Every time you wash a synthetic garment, 700,000 pieces of microplastics break off.) Cigarette butts shed microplastics. So do wet wipes. Almost anything used on the exterior of your house—like siding and paint—generates microplastics. If it’s plastic—and 12 percent of everything you throw out is—it will eventually break down into microplastics.
How many pieces of microplastics do you consume yearly? Estimates vary, with a 2019 study in Environmental Science & Technology estimating anywhere from 74,000 to 121,000 particles—numbers many other scientists consider an underestimate.
Many experts say you probably consume at least five grams of microplastics per week, or the equivalent of the plastic in one credit card. It might be two credit cards before long. Scientists at the University of Hawaii at Manoa have been measuring levels of microplastics in the placentas of Hawaiian mothers from 2006 to 2021. In 2006, 60 percent of placentas contained microplastics. In 2021, it was 100 percent. The results were published in the journal Environment International in 2023.
There are many unanswered questions about microplastics and health. How many particles are trapped in our bodies and how many are eliminated through excretion, urination, and sweat? Where do they go in the body? What effects do they have?
The newest research shows the effects are probably harmful, and even deadly. As scientists continue to conduct research, microplastics will probably become one of the most dominant health stories of the 21st century.
Heart attacks and strokes. In a study published in the March 6, 2024, issue of the prestigious New England Journal of Medicine, researchers looked at the level of microplastics in the arterial plaque of 257 patients with heart disease. Over the nearly three years of the study, patients with microplastics in their plaque were 4.5 times more likely to have a heart attack or stroke (or die from any cause) than patients without microplastics.
The researchers said it appears microplastics make the plaque more frail, increasing the risk that it could dislodge from an artery wall and trigger a heart attack or stroke.
Weakened immunity. Macrophages are immune cells that engulf and kill bacteria and viruses, and clean up dead cells. In a 2024 study, researchers found that microplastics kill macrophages—and the more microplastics absorbed by a macrophage, the higher the death rate. Similarly, another researcher found that immune cells that come in contact with microplastics die three times as quickly as those that do not.
Reproductive health. Scientists at the University of New Mexico detected microplastics in human testicular tissue. The most prevalent type of plastic was polyethylene, which is used to make plastic bags and bottles. It contains chemicals that can interfere with the development of sperm and imbalance hormones.
Brain disease. Scientists in Turkey found microplastics in the human brain—including in the tumors of patients with brain cancer.
Researchers from the University of Rhode Island exposed laboratory animals to microplastics, and found that those with the highest brain levels quickly developed behaviors similar to dementia in people.
There are many simple ways you can cut down your intake of microplastics.
