- Tiny plastic particles are in our food, water, and blood, and experts don't know how they affect our health.
- Scientists found microplastics in samples taken from living, human lungs.
- Recent research also found similar particles in human blood and stool.
Scientists have found tiny pieces of plastic in the lungs of living humans, adding to concerns about the impact of microplastics on health.
Bits of plastic dust have been floating around our environment for as long as humans have been using plastic, but scientists have only recently started investigating how these particles may affect our health. Microplastics are by definition smaller than a pencil eraser, so humans and animals may inhale or ingest them without knowing.
Past studies have identified microplastics in human stool and autopsy samples, but this is the first time scientists have discovered plastic particles lodged in the lungs of living patients.
A team of researchers at Hull York Medical School in the UK analyzed lung tissue taken from 13 patients undergoing surgeries — a relatively small sample, the authors noted. But of that select group, samples from 11 patients contained microplastics, according to findings described in the journal Science of The Total Environment.
The researchers found microplastics in all levels of the lungs — upper, middle, and lower lung regions — but the level of pollution in the lower lungs was particularly surprising, one author noted.
"We did not expect to find the highest number of particles in the lower regions of the lungs, or particles of the sizes we found," Laura Sadofsky, a senior author of the study, told the Guardian. "It is surprising as the airways are smaller in the lower parts of the lungs and we would have expected particles of these sizes to be filtered out or trapped before getting this deep."
The types of plastic they found are most commonly used in soft drink bottles, food packaging, and bits of machinery. While scientists do not yet know how plastics would affect the health of the lungs or otherwise, this discovery underscores the widespread and persistent nature of microplastic pollution.
Microplastics have also been found in human blood and poop
Microplastics are in the food we eat, the water we drink, and the air we breathe, experts previously told Insider. By one estimate, the average person ingests about a credit card's worth of plastic each week.
Some of that plastic leaves our bodies the old-fashioned way: via the digestive tract. Studies that found microplastics in human feces proved that the pollutants pass through our bodies, but it wasn't enough evidence for scientists to raise alarms about health risks.
However, the more recent discovery of microplastics in human blood confirmed that some plastic particles absorb into the bloodstream. Experts don't know for sure how this plastic exposure affects human health, but they said it was "unsettling news" nonetheless.
Scientists will continue to test human blood, as well as gut and lung tissue, to better understand the impact of microplastic pollution.