Bottled Water Has Much More Plastic Than Thought

Your goal is hydration, but in gulping down a liter of bottled water, you're also consuming hundreds of thousands of microscopic pieces of plastic, according to new research. Previous studies have found traces of plastic in bottled water. But in a new study, researchers found that plastic accumulates in bottled water at much higher rates than we realized: up to 100 times higher. In tests on bottled water from three leading, unnamed brands, scientists found between 110,000 and 370,000 detectable fragments of plastic per liter, with 240,000 fragments on average, AFP reports. These tiny fragments, which leach chemicals when heated in the body, are thought to come not just from the bottle, but also the filters used to purify the liquid, according to the study published Monday in PNAS.

Scientists used a new technique, Stimulated Raman Scattering microscopy, to detect nanoplastics, which are much smaller than microplastics, ranging in diameter from 1 nanometer, or one millionth of a millimeter, to 1,000 nanometers (1 micrometer or 0.001 millimeter). That's small enough to "pass through the digestive system and lungs, entering the bloodstream directly," per AFP. They can then reach the brain, heart, and other organs, even the cells of unborn babies. About 90% of plastics detected in bottled water were nanoplastics. Microplastics, at less than 5 micrometers in diameter, made up the rest. Nylon, believed to come from water filters, was the most common type found. The second most common type was polyethylene terephthalate, which is what the bottles are made of.

Think of plastic like skin, one expert tells the Washington Post. It's "constantly shedding," even if we can't see it, which is why microplastics have been found just about everywhere on earth. There is limited research on the impacts of microplastics on the health of humans and ecosystems, though "some early lab studies have linked them to toxic effects, including reproductive abnormalities and gastric issues," per AFP. "Whatever microplastic is doing to human health, I will say nanoplastics are going to be more dangerous," study co-author and Columbia University chemistry professor Wei Min tells the Post, noting they appear at much higher concentrations. Researchers say those concerned about nanoplastics in bottled water should consider switching to tap water, which also carries microplastics, though at much lower levels. (More plastic stories.)