According to a study of plastic particles in the air, micro-contamination is now spinning around the world.
According to the researchers, pollution by humans has led to a global plastic cycle, similar to natural processes such as the carbon cycle, with plastic moving through the atmosphere, oceans and land. The result is the ‘plasticization’ of the planet, said one scientist.
The analysis calls plastic pollution one of the most pressing environmental issues of the 21st century. This indicates that the billions of tons of plastic that are thrown away in the oceans and land and broken down into small pieces are thrown back into the air by road traffic and meander across sea and agricultural land.
It is already known that people breathe, drink and eat microplastics, and other research suggests that pollution levels will rise rapidly. The scientists said it ‘raises questions about the impact of the accumulation of plastic in the atmosphere on human health. Inhalation of particles can be irritating to lung tissue and lead to serious diseases. ”
Prof Natalie Mahowald, at Cornell University in the USA and part of the research team, said: ‘What we are currently seeing is the accumulation of mismanaged plastics that is just going up. Some people think it will increase tenfold [per decade].
“But maybe we can solve it before it becomes a big problem, if we manage our plastic better, before it accumulates in the environment and blows around everywhere.”
She said that cleaning up ocean plastic could help reduce the amount that is thrown back into the atmosphere, and that more biodegradable plastic could be part of the solution.
The research, published in the journal Proceedings of the National Academy of Sciences, examined microplastics in the air, which have been much less studied in oceans and rivers than plastics.
The team had more than 300 samples of microplastics in the air from 11 sites across the Western USA, the best collection available worldwide. This was the basis for atmospheric modeling estimating the contribution from different sources, the first study to do so.
The scientists have virtually none of the aerial microplastics directly derived from plastic thrown away in cities and towns, but it was the result of road traffic and winds over oceans and agricultural land that had already whipped up plastic particles in the area.
“We thought population centers would obviously be a much better resource, but it just didn’t work out that way,” Mahowald said. ‘Resuspension [of microplastics] makes the most sense with this set of data. ”
They found that roads were the predominant factor in the western US, linked to about 85% of the microplastics in the air. It probably contains particles from tires and brake pads on vehicles, and plastic from waste that has been ground. The oceans are estimated to be the source of about 10% of the air plastics in the western part of the US, and the land is 5%.
The researchers have expanded their modeling work to a global level, suggesting that while roads are probably also the predominant driver of plastic in the air in Europe, South America and Australia, plastic particles inflated from countries can do a lot be greater factor in Africa and Asia.
The modeling has shown that smaller microplastics can stay in the atmosphere for a week, long enough to blow over the continents. It has also shown that plastic pollution will fall on Antarctica.
The scientists said that the lack of observations in many parts of the world means that there were great uncertainties in their estimates. Their work shows in particular a lack of data on plastics in the air above the oceans. They said that work to understand the sources and effects of microplastics in the atmosphere should be a priority.
Prof Andreas Stohl, at the Norwegian Institute for Aeronautical Research and not part of the study team, said: ‘What people have been doing for decades now is what I call a’ plasticization ‘of the landscape and oceans.
“The study confirms the nature of microplastic transport in the atmosphere on a global scale and does a good job in highlighting many relevant and relevant possibilities, but more measurement data is needed to get a better picture of the sources.”
Stohl said: ‘People need to be concerned about microplastics in the air. First, because they will inhale it and it will most likely have health consequences. And secondly, because the atmosphere is a good distributor. It transports plastic particles to regions where we definitely do not want them: agricultural fields, national parks, oceans, the Arctic, even Antarctica. Eventually we will have extraordinarily high concentrations of plastic everywhere. ”
Microplastic pollution has been detected across the planet, from the summit of Mount Everest to the deepest oceans. The unveiling in December of small plastic particles in human placentas has been described by scientists as a matter of great concern.