The Invisible Health Threat of Microplastics

By now, you’ve probably heard: Microplastics have infiltrated the deepest corners of our ocean, the air we breathe, and pretty much every organ in our body. Even newborn babies are coming out prepolluted due to microplastics in mom’s placenta. While these tiny pieces of plastic (less than five millimeters in size) are certainly harming the environment, they’re also messing with our health—likely more than we currently understand.

What does current research show? Microplastics are small enough to slip past the biological barriers and filters that normally protect us from harmful substances. Because our body can’t break them down, they may contribute to or even cause serious health problems; scientists suspect that they increase our risk of heart attack and stroke, infertility, digestive and respiratory problems, and possibly colon and lung cancer.

Now a recent study in Nature Medicine suggests they may be detrimental to your brain, too: After examining postmortem tissue samples, researchers found that the brain had 7 to 30 times higher concentrations of microplastics and nanoplastics compared to other organs (like the liver or kidney). What’s more, there was up to 10 times more microplastics in the brain tissue samples of people who had been diagnosed with dementia compared to those without the disease.

So just how bad are microplastics for your health? And what can you do to minimize your risk? To find out more, we consulted a slew of experts and took a deeper dive into the growing body of research.

Microplastics And Our Health

As of 2019, the average American consumes somewhere between 39,000 and 52,000 microplastic particles every year. We don’t know the full extent of how much havoc they wreak on our health because research is sparse—but fair to say, it’s pretty bad.

“These plastic fragments are lodging in the human body, in our blood, lungs, brains, and liver and even the placenta, and breast milk,” says Judith Enck, a former EPA Regional Administrator and the president and founder of Beyond Plastics. “Once microplastics have breached the blood-brain barrier, there is nowhere else in the body for them to migrate to.”

Research on mammals shows that microplastics and their smaller relatives, nanoplastics, absorb and carry harmful substances like phthalates, heavy metals, and other chemicals used in plastic production. These toxins are all well-known to disrupt the endocrine system—the network that controls all your hormones. This disruption can affect everything from your brain to your nervous system and reproductive organs. What’s more, in 2024, Tracey Woodruff, PhD, MPH, a professor of reproductive sciences at UC San Francisco, and her team published a large systematic review that found microplastics increase inflammation and oxidative stress pathways in animals—two factors known to directly increase our risk for cancer.

We don’t know exactly how dangerous microplastics are compared to other known cancer-causing substances. However, Woodruff points out that, at five millimeters, microplastics are the same size as the tiny air pollution particles that the EPA strictly regulates—called particulate air matter pollution—which can travel deep into your lungs and possibly enter the bloodstream. Because we know these small pollution particles can seriously harm our health because of their size, Woodruff says microplastics likely pose similar risks simply because they can reach the same sensitive parts of your body.

How Microplastics Enter the Body

Microplastics enter your body pretty much every way you can conceive: Anything you eat, drink, or touch that was packaged in plastic more than likely has microplastics on or in it. Top offenders include plastic bottled water, food reheated in plastic containers, and highly processed foods like chicken nuggets—but the list of offenders is extensive and touches even the most plastic-conscious people. As Woodruff adds: “The reality is everyone is exposed to microplastics. So even if the health risk is small...everyone is exposed.”

We’re all inhaling a huge amount of microplastics from the air we breathe, as well as absorbing them through our skin through multiple different sources, from the clothes we wear to the skin care we use to the polluted soil and air we touch, Enck says. It’s also worth noting that plastic becomes even more toxic when heated; the more agitated the molecules become, the more they shed, Woodruff explains. (That’s why heating food in plastic Tupperware is really bad for you.)

While BPA-free plastic is better than the traditional stuff, the reality is there are over 16,000 chemicals potentially used or present in plastics. So while a company might not be using BPA to make your water bottle, they’re using its cousin or sister chemical instead, which probably also sheds microplastics, Woodruff explains.

Basically, research has shown how harmful BPA is to human health, but we haven't yet studied the other 15,999 chemicals in plastic to know where they fall on the spectrum—however, chances are pretty high they’re also not good for you.

Our Increasing Exposure

That same 2025 study linking microplastic levels with dementia dug up another very interesting fact: People who died in 2024 had 50 percent higher levels of microplastic in their tissue than those who passed away in 2016. Both Enck and Woodruff knew immediately what had changed in the last eight years: Plastic production has dramatically increased—it’s doubled since 2008, in fact.

You see, nearly all plastic is made from fossil fuels. And as the renewable energy industry grew, the fossil fuel industry needed a way to make up for lost profits, Woodruff explains. They started making more plastic and persuading manufacturers to use plastic in more items.

That means that not only is there more microplastic residue in everyday items we use but there is also more microplastic pollution in the air we breathe. Even scarier: Plastic production is expected to triple by 2060—so our current exposure is really the tip of the iceberg of what’s coming if we don’t make changes, Woodruff says.

7 Ways to Reduce Your Exposure

Rather than spiraling into anxiety about all the ways we’re ingesting plastic all the time, start by doing what you can—it will make a difference for your own health in the shorter term and it can influence consumer trends over time.

We don’t yet know how long microplastics stay in the body. But Woodruff says that with any pollutant, minimizing exposure is your best bet to lowering your levels—even if it takes a while. Here’s how.

1. Vote for more regulation.

Perhaps the single best thing you can do to minimize your exposure to microplastics is to support laws that limit plastic production or ban the chemicals altogether, both our experts agree. Because we don’t know the exact chemicals used in different sources of plastic, we don’t know the true risks they pose. Moreover, many of the chemicals used to manufacture plastic are unnecessary and can be banned and replaced with safer alternatives, Enck says.

Think about the number of fruits and vegetables at the store unnecessarily packaged in single-use plastic, potentially leaching into what we eat. Or the amount of plastic used in tires heating up on the roadway, or in paint heating in the sun, all affecting the air we breathe.

History confirms that when bans are put into place (or allowable levels lowered)—like for flame retardants, lead in air, phthalates—people's levels of exposure decreases, Woodruff adds.

2. Switch to natural clothing, especially for your workouts.

Clothing is the world’s largest source of primary microplastics, making up about 35 percent of the total. This affects everyone—nearly 70 percent of all textiles are plastic, which our skin absorbs when we wear them. And these plastic-containing fabrics also shed the most microplastics when we wash them.

Even eco-friendly apparel can’t escape: Clothing made from recycled plastic might be better for the environment, but it’s potentially worse for our health. Studies show that recycled polyester releases more microplastic than virgin polyester. Woodruff explains that recycled fibers are rougher, causing more abrasion and, therefore, more shedding. The effects are even worse for workout clothes, usually made from recycled or synthetic fibers, since sweat may increase the chances of the toxic particles being absorbed through the skin.

Your best bet: Opt for clothing made from natural fibers (e.g., cotton, linen, wool, hemp, silk, jute) as often as possible—even partially, as 100 percent is hard to come by. And hang any synthetic or recycled fabrics to dry rather than heating them in the dryer.

3. Invest in a HEPA air purifier—and vacuum often.

Even the most plastic-free households are exposed to the microparticles in the air we all breathe. Keep dust levels down by vacuuming regularly, taking off shoes before indoors, and running an air purifier, Woodruff advises. Make sure your air purifier has a HEPA filter, which is proven to remove up to 99.97 percent of airborne particles as small as 0.3 μm, including a significant amount of airborne microplastics.

4. Keep skin-care products out of the sun.

We don’t always have control over our favorite skin-care products coming in plastic packaging, but we do have control over where they’re stored. Woodruff explains that heat and sunlight breaks plastics down, making them shed microparticles faster. It’s smart to keep your plastic-encased skin-care products in the bathroom out of direct sunlight, especially if you live somewhere with strong rays, and try to put your steamy shower products into glass containers. During the summer, keep your sunscreen tucked safely inside your beach bag.

5. Opt for loose-leaf tea.

As mentioned, heating plastic is one of the best ways to release microplastics into food or drink. Tea bags are often plastic and, even those labeled food-grade still release millions of micro- and nanoplastics, studies show. An easy switch: loose leaf tea with a metal steeper.

6. Shop locally and at farmers’ markets.

Eating lower on the food chain—that is, more fruits, vegetables, and grains—helps reduce your microplastic exposure, Woodruff says. Even better: Shop at smaller or farmers markets, where the food hasn’t come from as far away and where they often use less unnecessarily single-use packaging on the produce.

7. Make swaps in your kitchen.

Plastic cookware can add thousands of microplastics to your body each year (especially conventional nonstick pans and any black spatulas or other utensils, which can contain Teflon and toxic flame retardants, respectively). So it's safe to say you should look around your kitchen and swap out anything plastic—cutting boards, teakettle, Tupperware—for a glass, steel, ceramic, or other 100 percent natural-fiber alternative if you can. Also on the out: plastic sponges, which release hundreds of tiny plastic particles in just 30 seconds of scrubbing (opt for a bamboo bristle brush instead).