Bottled water contains thousands of nanoplastics, new study shows. How can you avoid them?

Scientists from Columbia University are raising alarm bells about the amount of small flecks of plastic — known as nanoplastics — in bottled drinking water. Their research, which was published on Jan. 8 in the journal Proceedings of the National Academy of Sciences, found that three popular plastic water bottle brands (which went unnamed in the research) had 10 to 100 times greater amounts of nanoplastics than previously estimated.

That’s not good news, especially since many people pick bottled water over tap assuming that it’s the safer, cleaner option. Nanoplastics — which are tiny plastic particles that are smaller than .001 millimeters, as well as the larger microplastics, which are particles smaller than 5 millimeters (about the size of pencil eraser) — are potentially a threat to our health. Here’s what to know about these plastics — and what you can possibly do to avoid them.

Why are microplastics and nanoplastics potentially harmful?

Microplastics and nanoplastics occur when larger pieces of plastic are broken down into small pieces. These plastic particles are now ubiquitous — found in our water supply, in soil, in the air and in the food we eat. These particles are also now in us.

“Several recent studies have documented the accumulation of microplastics in the human body, including the placenta, heart tissue, lung tissue and others,” Tasha Stoiber, a senior scientist at the Environmental Working Group, tells Yahoo Life. This is a problem, she notes, because microplastics can be carriers for chemical contaminants. Recent studies are now documenting the potential harms from microplastics exposure, which include inflammation in the body, changes in metabolism and damage to reproductive health.

Nanoplastics, specifically, are a cause for concern. Because of their small size, nanoplastics can be absorbed into human cells and are capable of crossing the blood-brain barrier, which, according to Cleveland Clinic, is a protective barrier made of cells that "defend your brain from harmful substances, germs and other things that could cause damage." A December 2023 study from Duke University found that nanoplastics may interact with brain proteins, leading to changes linked to Parkinson’s disease.

“In laboratory settings, nanoplastics have been found to bypass the [gastrointestinal tract] or lungs and have been found to migrate to systemic tissues,” Phoebe Stapleton, associate professor of pharmacology and toxicology at Rutgers University, tells Yahoo Life. “In vitro studies done on cells have shown that the cells can take the nanoplastics and internalize them,” which can lead to DNA damage and cellular death.

How concerned should you be about nanoplastics and microplastics?

The World Health Organization (WHO) states that there is no reliable information that suggests microplastics in drinking water are a human health concern. However, the WHO also points to the limited research on the topic.

Experts agree that more research needs to be done on the potential health harms caused by microplastics and nanoplastics, but the fact that they are everywhere is a problem. Erika Veidis, the human and planetary health program manager at Stanford University’s Center for Innovation in Global Health, says that 80% of tap water samples globally were found to have some level of microplastics.

That is “dangerous in itself,” she tells Yahoo Life. “In the event that additional health impacts are uncovered, removing such a pervasive contaminant is an incredibly difficult task — one that I can't imagine being able to comprehensively address.”

The other problem? We’re not slowing down our use of plastic, which will lead to more microplastics and nanoplastics in the water we drink, products we use and food we eat. In fact, demand for some of the most common types of plastic, including ones used to make plastic bottles, is expected to skyrocket by 90% by 2050.

Is there a way to avoid nanoplastics and microplastics in drinking water?

Unfortunately, it’s virtually impossible to completely eliminate microplastics and nanoplastics from our lives — the horse is already out of the barn, even if we completely stopped all plastic production today. However, that doesn’t mean there aren’t better options when it comes to drinking water at least.

A 2018 study found that tap water has fewer microplastics than bottled water, making it a likely better bet. Filtering your water is another possible way to decrease microplastics in drinking water. “To reduce exposure to microplastics, opt for filtered water and use a refillable stainless-steel water bottle, steering clear of plastic water bottles,” says Stoiber. (Yes, that's your permission to purchase one of those ever-popular Stanley Cups.)

However, there is still work to be done to get water filters to the point where they are completely removing these small plastics. Filters will thus far work only on microplastics, as “unfortunately, we cannot filter out the nanoplastics,” says Stapleton. “Nanoplastics are about the size of a virus and they are too small to be caught in most filters.”

Since microplastics are everywhere, the best way to avoid them is to limit your exposure where you realistically can. Experts agree that, in general, the less plastic you use, the better. That doesn’t mean never drinking from a plastic water bottle again, however. If you grab a bottle of water at the gym or the office daily, swap it out for a reusable water bottle that you fill up from home with filtered water. That way, when you are in a pinch and do need to purchase a plastic water bottle — say, at the airport — you can do so knowing you’ve at least cut back in other ways.