Have you ever wondered what gives your skin scrub its slightly scratchy feel? Instead of an organic ingredient like apricot peel, it might be microbeads, tiny plastic bubbles less than a millimeter wide.

These beads show up in countless personal hygiene products, from shower gels and body scrubs to toothpastes and cosmetics. A United Nations study found that a typical exfoliating shower gel contains as much microplastic as the plastic packaging it arrives in, and a single tube of toothpaste can contain up to 300,000 of the Lilliputian spheres.

The trouble is, microbeads are forever: They don’t dissolve or degrade. Billions of them are washed down drains each year, slipping through water treatment plants and flowing into rivers, lakes and ultimately the ocean, where fish and other marine life ingest them.

The beads can absorb toxins such as DDT and PCBs (linked to cancer and reproductive problems) that pollute our waterways. Scientists worry the beads — and the toxins — may eventually turn up on our plates.

Among the first scientists to investigate this problem is Sherri Mason, PhD, an associate professor of chemistry at the State University of New York at Fredonia. She found that microbeads have infiltrated all five of the Great Lakes, which hold 20 percent of the earth’s fresh water.

“These plastic beads are incredibly small — no more than 1 millimeter or less in size. That’s as big as the period at the end of a sentence. To marine life, they look like fish eggs, and for some fish that’s food,” says Mason. “There is no documented evidence yet, but the concern we now have is that the microbeads are making their way into the food chain.”

How bad would that be? Microbeads are made primarily from polyethylene and acrylates copolymer, and, according to government regulators, they’re considered safe when intact. Mason is not so sure, pointing out that polyethylene and the like are made from monomers that have been linked to cancer.

Another concern, says Mason, is the threat to wildlife. Fish, turtles and seagulls have been known to eat microbeads, which can get stuck in their stomachs, clogging their digestive tracts and causing starvation.

Related: Why You Should Break Your Bottled Water Habit

Plastic in our drinking water?

While plastic pollution in our waterways is hardly new, the problem of microplastic beads is more recent. In 1992 manufacturers started receiving patents for microbeads in cosmetics and personal care products. At that point, microbead use exploded, eventually replacing natural but more expensive exfoliating ingredients like saltsugar and oatmeal, according to a factsheet published by the Metropolitan Water Reclamation District of Greater Chicago, one of the largest water treatment plants in the world.

Wastewater officials say that billions of microbeads are slipping right through their filters.

“There are some microbeads that don’t get through our water treatment facilities,” says David St. Pierre, the water district’s executive director. “But there is no treatment process to specifically address the problem of these very, very small microbead particles. Even in treatment plants with sand filters, which eliminate any suspended solid to achieve drinking water quality, they get through.”

Related: 9 Things You Probably Didn’t Know You Could Recycle

Banning the beads

Building new wastewater treatment facilities, some of which date back to the 1940’s, is too costly, says St. Pierre. “The best way to eliminate microbeads in personal care products is to ban them. Those of us in the water treatment industry recognize that this is the right solution,” he says.

Illinois last year became the first state to ban all personal care products containing microbeads smaller than 5 millimeters by 2018. Maine, New Jersey, Colorado, Maryland and Indiana also have passed microbead bans, and California is poised to follow suit. At least a dozen other states and the federal government are considering similar bans.

Several major consumer product manufacturers support the bans or have decided to voluntarily pull microbeads from their cosmetic and personal hygiene products.

What you can do

“We need laws but every little bit helps,” says Mason. “People can change what they buy. The industry responds to consumer concerns and public pressure.”

Mason urges consumers to read the labels of toothpaste, deodorant, cosmetics and other personal care products and avoid buying products that contain polyethylene or polypropylene (plastics used in microbeads), she says. There’s at least one app on the market that help you determine which products are made with microbeads.

If you own products that contain them, Mason suggests dumping them or, better yet, returning the unused portion to the manufacturer with a note voicing opposition to microbeads.

What to use for your facial scrub? “Use natural alternatives like sugar, salt and ground up seeds or nuts,” says Mason. “You even can use crushed up cocoa beans. It’s like washing your face with chocolate rather than plastic.”

Related: How to Dispose of Lightbulbs and 9 other Hazardous Items

Carolyn is an award-winning investigative journalist, writer and editor with more than 25 years of experience in newspapers, magazines, digital journalism, documentary films and books. She was a longtime contributor to The New York Times, covering national and foreign news, and has written for numerous publications including Mother Jones, Forbes, The Nation, and The Washington Post. Her expertise ranges from health, biotechnology and science reporting to breakthrough technologies in Silicon Valley. She continues to freelance and report on finance for Blueshift Research. Her favorite safety tip: don't walk barefoot in the urban outdoors (and buy flood insurance).