Microplastic is raining down upon you. Right now. Everywhere. From article in WIRED and PNAS: plastic in the air, from the sea and land.

A new report in “Wired” describes microplastics floating in the sky and raining down upon everyone, even in the most apparently pristine wilderness. The report describes a modeling study published in “Proceedings of the National Academy of Sciences” on April 11, 2021. The model “constrains” the source of the roughly 1,100 tons of plastics suspended in the air over the western United States (US) at any given time.

Since the appearance of microplastics is anonymous (only tire dust can be distinguished from other types of plastics) it was incumbent upon the researchers to calculate the sources from various parameters. For example, once suspended in air, the average plastic particle remains floating for about a week. Circulation of the air, therefore, suggests that a large proportion of plastic in the air comes from the marine environment and is probably launched by wave action from the sea.

Plastic dust from land sources is probably launched into the air by car and truck tires on the roads. Some of this dust comes from the tires themselves. A significant amount of plastic comes from cloth: tiny particles break off when you wash your clothes and are suspended in the water, then go to waste treatment plants and end up in the sewage sludge which is spread on fields as fertilizer. Much of the rest is produced by degrading plastic debris left as trash on the roadsides.

Despite these uncertainties, the authors of the study say: ” Results suggest that atmospheric microplastics in the western United States are primarily derived from secondary re-emission sources including roads (84%), the ocean (11%), and agricultural soil dust (5%).”

Studies of this type are necessary because microplastics have become an universal scourge of the twenty-first century. Plastic debris is everywhere, especially in the ocean, and the amount in circulation increases every year. No effective, practical means has yet been found to remove significant amounts of plastic waste from the ocean. Organisms from single-cell to whales ingest plastic, often mistaking it for food. Malnourished or starving fish, birds, and marine mammals wash up on beaches with their stomachs full of plastic, especially plastic bags.

Over the next few years, our planet will be increasingly blanketed with invisible microplastics. Unsightly plastic bags, toys, shoes, and other debris will appear more and more often on our beaches. Often, animals will choke on larger pieces of plastic or be strangled by plastic objects (like the rings that hold six-packs of beer together).

Micro-organisms that use plastic as a source of energy (that is, feed on plastic) are evolving only too slowly. We can encourage this evolution by searching for these “bugs” and seeding them into environments that are already saturated with plastic debris. Before spreading such organisms we will need to test them to make sure they are benign.

We can imagine a nightmare scenario in which plastic boat hulls will suddenly begin to disintegrate in seas that are overtaken by plastic-eating bacteria. The alternative will be malnourished fish and birds and ugliness over all our coastlines.

Overpopulation and “convenience” have led to ubiquitous plastic littering our planet. People must do our best to try to clean up the environment, literally by picking up after ourselves.

(seagull by Eveline de Bruin courtesy of Pixabay.com)