By Kaitlyn Scanlon, Alliance Intern from Oregon State University ’26
Ever heard of microplastics? They’re defined as miniscule plastic pollutants found just about everywhere: drinking water, the ocean, and now clouds. A study by Japanese scientists from Waseda University found microplastics to be present in clouds, and that they may be contributing to climate change. The study’s lead author Hiroshi Okochi explained that “when microplastics reach the upper atmosphere and are exposed to ultraviolet radiation from sunlight, they degrade, contributing to greenhouse gasses.”
The scientists found that for every quarter gallon of cloud water tested, 6.7 to 13.9 pieces of microplastic were detected. Okochi issued a warning regarding the foreboding research, saying that “if the issue of ‘plastic air pollution’ is not addressed proactively, climate change and ecological risks may become a reality, causing irreversible and serious environmental damage in the future.”
Waseda University suggested that as “ten million tons” of microplastics journey from the ocean to the atmosphere, they “may have become an essential component of clouds, contaminating nearly everything we eat and drink via ‘plastic rainfall.’”
To conduct the study, scientists scaled Mount Fuji and Mount Oyama to procure water samples sourced from the mist surrounding the peaks. By utilizing advanced imaging technology when assessing the samples, they discovered “nine different types of polymers and one type of rubber in the airborne microplastics, which ranged in size from 7.1 to 94.6 micrometers (under 0.004 inches).” They predict that “they are likely affecting the climate in ways that are not yet fully understood.”
Previously, research was quite scarce on how microplastics traveled to far-ranging locations like Arctic sea ice, mountains, and even the inside of fish. The authors of this study reported that “to the best of our knowledge, it’s the first report of airborne microplastics in cloud water.” The findings in this paper are both grave and scientifically crucial because of the pervasive and potentially harmful nature of microplastics. In fact, “emerging evidence has linked microplastics to a range of effects on heart and lung health, as well as cancers, in addition to widespread environmental harm.”
Hearing news of such widespread plastic contamination may invoke feelings of anxiety and fear, especially since this is not an issue the average consumer can easily address. WIth that said, becoming an informed, mindful consumer is the first step to changing your future, so keep learning and taking action!