An anonymous reader quotes a report from Scientific American: Scientists have detected tiny pieces of plastic falling out of the air like artificial dust. A first-of-its-kind study finds these particles have blown in on the wind from at least 100 kilometers away and likely much farther. This is a clear indication that atmospheric transport is yet another way plastic pollution is being distributed around the planet, even to remote areas. “And it suggests that this is a far bigger problem than we have currently thought about,” says study co-author Deonie Allen, of the Ecole Nationale Superieure Agronomique de Toulouse (ENSAT).
The study, published Monday in Nature Geoscience, is one of only a handful that have attempted to measure how much plastic is falling from the atmosphere. It marks the first wave in what is likely to be a flood of such studies in the coming years, in an effort to fill in the picture of how microplastics move around the environment and how humans might be exposed to them. Allen and her colleagues knew microplastics had been found in rivers and sediments in the French Pyrenees, but no one had determined the sources. The bulk could not have come from local sources because of the small human population and limited industrial activity, so Allen was struck by a key question: “Why haven’t we looked up?” That is what she and her colleagues did, taking advantage of atmospheric measuring equipment already in place in the Pyrenees and sampling over five months. They found plastic fibers, films and shards, all in a range of sizes. Most of the polymers that turned up in the samples were polystyrene, polyethylene and polypropylene, which are all common in single-use plastic products such as bags and foam food containers. The study used computer models of atmospheric currents to attempt to backtrace the air that brought the microplastics in the Pyrenees, which is considered a pristine environment. It was clear that the relatively small towns and villages nearby “were unlikely to account for all of the plastic they detected, which suggests the ultimate sources are more distant,” reports Scientific American.
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