Every breath people take in their homes or car probably contains significant amounts of microplastics small enough to burrow deep into lungs, new peer-reviewed research finds, bringing into focus a little understood route of exposure and health threat. The Guardian: The study, published in the journal Plos One, estimates humans can inhale as much as 68,000 tiny plastic particles daily. Previous studies have identified larger pieces of airborne microplastics, but those are not as much of a health threat because they do not hang in the air as long, or move as deep into the pulmonary system. The smaller bits measure between 1 and 10 micrometers, or about one-seventh the thickness of a human hair, and present more of a health threat because they can more easily be distributed throughout the body. The findings "suggest that the health impacts of microplastic inhalation may be more substantial than we realize," the authors wrote.Read more of this story at Slashdot.