It was only a matter of time. Scientists, following up research showing tiny particles of plastic in everything from bottled water to salt, say they've found "the first evidence for microplastics inside humans." All stool samples taken from eight participants of a small study by Environment Agency Austria were found to contain plastic particles ranging in size from .002 to .02 inches, with 20 particles per 10 grams of excrement on average, report the New York Times and Guardian. Up to nine varieties of plastic were identified, with types used in bottles and caps (polypropylene and polyethylene terephthalate) appearing the most often. The participants were as varied. Hailing from eight countries including the UK, Japan, and Russia, all ate food wrapped in plastic or drank from plastic bottles. Six consumed sea fish.
This suggests plastic contamination during food processing or packaging and "indicates a high likelihood that also many other people involuntarily ingest microplastics," Philipp Schwabl, lead author of the study yet to be published in a peer-reviewed journal, tells Live Science. Indeed, study authors say "more than 50% of the world population might have microplastics in their stools," per the Guardian. While further research will explore what this means for human health, researchers say microplastics could transmit toxic chemicals and pathogens and affect the digestive system's immune response. "The smallest microplastic particles are capable of entering the bloodstream, the lymphatic system, and may even reach the liver," says Schwabl, mentioning particular concerns for people with gastrointestinal diseases. (Proper contact lens disposal may help.)