Millions of tonnes of plastic waste are dumped in the environment and much is broken down into small fragments. Microplastics were already known to have polluted the entire planet, from the summit of Mount Everest to the deepest oceans.
However, nanoplastics are even tinier and have been difficult to collect and analyse. Researchers are concerned about the health impact of ubiquitous plastic pollution, and nanoplastics may be even more dangerous than microplastics as they are small enough to penetrate cell membranes and remain lodged in the body.
Taking samples from very isolated places avoids local sources of nanoplastics dominating the readings, and using glacier snow means only particles falling from the sky are collected.
The Alpine survey, published in the journal Scientific Reports, found nanoplastics in five of the 14 sites sampled in the French, Swiss and Italian Alps. The most abundant nanoplastic was tyre particles (41%), then polystyrene (28%) and polyethylene (12%). Each tyre on the world’s 1.6bn vehicles can lose 4kg during its lifetimes and may be the largest source of tiny plastic pollution.
People are already known to consume tiny plastic particles via food and water, as well as breathing them in. Microplastics have been discovered in human blood, semen and breast milk and in brains, livers and bone marrow, indicating profuse contamination of people’s bodies. The impact on health is as yet unknown but microplastics have been shown to cause damage to human cells in the laboratory and have been linked to strokes and heart attacks.