Microplastics, often acknowledged as a pervasive marine pollutant, have now emerged as a troubling presence in the atmosphere, raising considerable apprehensions about potential health risks for humans, according to recent research conducted in Japan.
Japanese scientists, spearheading investigations on this matter, have confirmed the infiltration of microplastics into the skies, where they subsequently find their way into clouds and snow. Concerns abound that these airborne particles could be ingested and subsequently penetrate the human vascular system.
Leading the charge in this nascent field of study are Hiroshi Okochi, a professor of environmental chemistry at Waseda University, and Hiroshi Ono, an associate professor at the Kitami Institute of Technology in Hokkaido.
Microplastics, measuring less than 5 millimeters in length, are formed through the breakdown of plastic waste by ultraviolet light and natural elements like wind and waves.
Due to their relatively large surface area, microplastics are deemed chemically hazardous as they can absorb and transport toxic substances. When consumed by organisms, these plastics release chemicals that can enter the human food chain via marine life, posing threats to both ecosystems and human health.
Okochi and his team conducted pioneering field observations from 2021 to 2022, demonstrating for the first time that microplastics were present in cloud water collected from various locations, including the summit of Mount Fuji.
These airborne particles, degraded by ultraviolet radiation, lose their water-repellent properties and are believed to serve as condensation nuclei for cloud ice and water.
Furthermore, the degradation of microplastics by UV light emits greenhouse gases, potentially affecting cloud formation and sunlight reaching the Earth’s surface, thereby interfering with global warming predictive models.
The researchers speculate that airborne microplastics originate from both terrestrial and marine sources. In Japan, marine microplastics are likely propelled from neighboring seas by typhoons and northwest winter monsoons.
Ono, specializing in cryology, discovered microplastics in snow. Analysis of snow samples collected from various locations in Hokkaido revealed the presence of microplastics, with synthetic rubber particles and relatively large microplastics primarily found in urban areas.
Despite their smaller size compared to oceanic microplastics, airborne microplastics deteriorate more rapidly due to exposure to intense UV light.
In terms of health concerns, inhaled microplastics are believed to accumulate in the lungs and finer particles may enter the bloodstream, posing challenges for expulsion unlike plastics ingested through contaminated food and beverages.
While the first reference to airborne microplastics emerged in 2016, the field still lacks standardized methodologies, hindering a comprehensive understanding of the situation’s severity.
“There are still many unknowns. We aim to elucidate the health risks, in particular, and explore potential mitigation strategies,” Okochi remarked, underscoring the pressing need for further research in this critical area.
