A heavy persistent drizzle, composed of billions of microplastic particles, should fall from Monday, May 29 on Paris, according to the very first "weather forecast of plastic pollution". This weather report of a new kind will be timely to welcome in the French capital the diplomats of 175 countries gathered for the negotiations of a future treaty on plastic pollution.

This precipitation, under a bright sky expected in the coming days, should represent daily between 40 and 48 kilograms of pieces of plastic suspended in the air over the French capital, told AFP the scientists authors of this unprecedented study.

Damage to health

"This should sharpen the attention of negotiators," says Marcus Gover, head of plastics research at Australia's Minderoo Foundation: "Plastic particles break down in the environment and this toxic cocktail ends up in our bodies, where it causes unsuspected damage to our health."

Concern about the impact of plastics on the environment and health has grown in recent years, along with the increase in research documenting their ubiquity.

In nature, multicolored microplastics – smaller, by definition, to five millimetres in diameter – have been found in the ice near the North Pole and in the bowels of fish swimming in the deepest corners of the ocean.

According to the United Nations Environment Programme (UNEP), plastic debris kills more than one million seabirds and 100,000 marine mammals each year. Blue whales, which feed by filtration, consume up to 10 million microplastics per day. On the human side, microscopic pieces have been detected in blood, breast milk and placenta.

Animal tests have linked chemicals in microplastics to increased risks of cancer, reproductive problems and DNA mutations. But data on human health is still lacking.

"Getting out of ostrich politics"

"The plastics in the body that should worry us the most are probably those between 10 nanometers and a micrometer," said pediatrician Christos Symeonides, a researcher at the Minderoo Foundation.

"They are the ones most likely to cross our biological membranes and penetrate tissues, including the blood-brain barrier," the barrier between the blood and the nervous system, he adds. "On the health risks of microplastics, we are just starting to get out of the ostrich policy," he said.

The forecast for this "plastic pollution weather" is only for much larger particles, mainly synthetic fibers of at least 50 microns. By comparison, a human hair measures about 80 microns (or 80,000 nanometers).

The method developed by the Minderoo Foundation, however, does not really measure in real time the plastic floating in the atmosphere. It extrapolates from research conducted in Paris since 2015, which has made it possible to collect samples from several locations throughout the year and sort them in the laboratory.

Led by French scientists, this pioneering work revealed that most of the plastic particles falling on the 2,500 square kilometers of the Paris urban unit were nylon and polyester, probably from clothing. And for a part, tire residues, scattered in particular during braking.

Last year, 175 nations agreed to conclude a legally binding treaty to reduce plastic pollution by 2024. If left unchecked, annual plastics production could triple by 2060, according to the OECD. It would reach 1.2 billion tons and waste would exceed one billion each year.

With AFP

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