• A new study finds that dishwashers may be another way microplastics are leeching into the environment and potentially impacting human health.
  • Microplastics have been linked to an array of health issues.
  • Keep reading to learn more about the findings and risks.

Whether or not an item is marked as “dishwasher safe,” some items are best hand-washed. Not just to avoid scuffing a prized plate, but also for your general well-being. A new study investigated how dishwashing plastic containers, specifically, contribute to microplastic pollution at large, in the home, and potentially, in human health.

Below, toxicologists break down the findings and explain how your most trusty appliance may be one of the avenues by which microplastics find their way into your body.

What Did The Study Find?

Researchers analyzed the wastewater produced by a domestic dishwasher after it cleaned a full load of plastic dishes and utensils and found that a single load could release about 920,000 micro- and nanoplastic particles into wastewater, which poses a threat to the environment and the water supply. The particles were measured for size, mass, and concentration of plastic. Based on the findings, daily dishwasher use could make each household responsible for the annual release of 33 million nano- and microplastic particles globally. However, compared to other sources of microplastic pollution like manufacturing, researchers found that dishwasher contribution is relatively low.

Microplastics are tiny plastic particles that are found in dirt, water, air, the food chain, and our bodies. There is still a lot more research needed to determine their concentration and health impacts, but their increasingly known presence has, understandably, raised significant health concerns in recent years (especially after research found that the human brain may contain up to a spoonful of microplastics!).

“They enter the environment through wastewater discharge and the degradation of larger plastic materials,” explains Rene Caballero, Ph.D., a research toxicologist at the National Sanitation Foundation. And plastic (low-quality plastic, especially) is easily degraded by heat, agitation, and abrasive detergents, the three main cleaning mechanisms used by dishwashers to make your flatware shine.

How Might This Impact Health?

The plastic particles from dishwashing plastic are discharged into wastewater, “where they may not be effectively filtered out before the water is reintroduced into the drinking water supply and consumed by humans,” says Kelly Krisna Johnson-Arbor, M.D., a toxicologist with MedStar Health.

Plenty of other studies have investigated the effects of microplastic exposure on human health and linked it to hormone disruption, inflammation, gut issues, metabolic issues, and cardiovascular disease. And although the true impacts of microplastics are not fully understood right now, people who are immunocompromised, children, pregnant people, and the elderly may be at more risk of developing health issues due to exposure. “Therefore, it is crucial for consumers to be proactive in reducing it,” says Caballero.

How To Reduce Your Microplastic Exposure

Just remember that, because the environment is so saturated with them, it’s “nearly impossible to entirely avoid them,” says Dr. Johnson-Arbor. But reducing your overall exposure with the following is thought to lower health risks.

  • Drink filtered water whenever possible, and install a tap filter that sifts out microplastics. “Read package labels carefully to ensure that the filters have small pore sizes that are effective in removing the tiny microplastic particles that are less than 5 millimeters in diameter,” which is the official size threshold for microplastics, says Caballero.
  • Avoid washing plastic dishes in the dishwasher, or avoid using plasticware altogether and replace what you can with glass, bamboo, and/or stainless steel.
  • Don’t microwave plastic containers.
  • Maintain appliances properly to ensure they operate efficiently and reduce the risk of microplastic contamination.
Headshot of Kayla Blanton

Kayla Blanton is a freelance writer-editor who covers health, nutrition, and lifestyle topics for various publications including Prevention, Everyday Health, SELF, People, and more. She’s always open to conversations about fueling up with flavorful dishes, busting beauty standards, and finding new, gentle ways to care for our bodies. She earned a bachelor’s degree in journalism from Ohio University with specializations in women, gender, and sexuality studies and public health, and is a born-and-raised midwesterner living in Cincinnati, Ohio with her husband and two spoiled kitties.