Microplastics in the clouds. Air contaminated with plastics

Japanese scientists have discovered microplastics in clouds at altitudes ranging from 1,300 to 3,776 meters above sea level. If we don’t solve this problem, the environment faces serious and irreversible consequences, warns Hiroshi Okochi of Waseda University, the study’s author.

Polymers over Mount Fuji

Published in the journal Environmental Chemistry Letters, the study is unprecedented evidence of the ubiquity of microplastics in Earth’s ecosystems. A team from Waseda University took water samples from clouds hovering over the peaks of Mount Fuji and Mount Oyama and subjected them to detailed physical and chemical analysis. Between 6.7 and 13.9 pieces of plastic particles measuring 7.1-94.6 μm were found in each liter of water tested.

The samples came from the atmospheric boundary layer and the troposphere, the layers of the atmosphere closest to us. The volatile microplastic in the clouds was formed by nine different polymers and one type of rubber. They included. polyethylene (PE), polypropylene (PP) and polyethylene terephthalate (PET), i.e. compounds well known from everyday life and practically ubiquitous. According to scientists, microscopic plastics in this case acted as condensation nuclei, i.e. particles that condition the formation of clouds in the process of attracting water and ice particles.

Microplastics in clouds, sea, lungs

Reports from Japan round out the alarming observations about the ubiquity of microplastics. Plastic particles smaller than 5 mm are already drifting in the world’s oceans in a shocking 50-75 trillion pieces. Most of them sink, littering the bottom, while others drift and are consumed by fish and other sea creatures. There is also increasing talk of microplastic contamination of soils, which not only threatens organisms such as earthworms, but significantly disrupts the microbial flora in the soil and its retention capacity, thereby worsening conditions for plant growth.

In 2022. Researchers at the University of Hull in England found microplastic particles in the lungs of all the people tested. They have also previously been identified in human blood and in the placentas of pregnant women. It is not known how the synthetic particles will affect human health, but it is suspected that they could, for example, be a vector for antibiotic-resistant bacteria.

How does microplastic get into the air?

Microplastics in clouds remain a phenomenon difficult to explain. Its presence in water and soil is fairly well studied and is associated with phenomena such as the degradation of plastic bags in open landfills and the use of micro-beads in cosmetics. Every year, up to 10 million tons of plastic enters rivers, seas and oceans from the land.

Also, harmful particles can enter the air as part of the landfill weathering process, through road dust, synthetic clothing, gradual tire wear or the increasingly popular artificial turf. A key role in the creation of “plastic clouds,” however, is likely to be played by the world’s oceans. The constant motion of the rippling water causes light particles to rise above its surface in the form of aerosol, and then, heated by the sun, travel up into the troposphere. There, after cooling, they undergo condensation to form clouds.

Microplastics in the clouds and climate change

Elevated more than a thousand meters above the sea surface, the microplastic is subject to stronger UV radiation. It is what makes the molecules change their character from hydrophobic to hydrophilic, that is, showing the ability to attract water. As a result, more clouds form in the sky, and this significantly affects the Earth’s climate. This is because more clouds mean more easily heated water vapor in the air, and at night it also means an extra layer of insulation to counteract the cooling of the air.

The sun’s rays, interacting with the microplastics in the clouds, also accelerate their degradation. As a result, there is an increased release of greenhouse gases, which intensify the process of global average temperature increase, in addition to increasing the level of air pollution.

Polymer molecules carried by the strong winds of the troposphere are able to travel very long distances. According to researchers at Waseda University, the accumulation of microplastics in the atmosphere, especially in the polar regions, will lead to major changes in the planet’s already overblown ecological balance. The result could be a drastic reduction in biodiversity and an acceleration in the rate of climate change.