In a study published in the journal Environmental Chemistry Letters, Japanese scientists climbed Mount Fuji and Mount Oyama in order to collect water from the mists that shroud the peaks, then applied advanced imaging techniques to the samples to determine their physical and chemical properties.
The team identified nine different types of polymers and one type of rubber in the airborne microplastics, which ranged in size from 7.1 to 94.6 micrometres.Each litre (0.26 gallon) of cloud water tested contained between 6.7 to 13.9 pieces of the plastics.“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,” lead author of the research, Hiroshi Okochi of Waseda University, warned in a statement on Wednesday.When microplastics reach the upper atmosphere and are exposed to ultraviolet radiation from sunlight, they degrade, contributing to greenhouse gasses, Okochi said.Microplastics – which are defined as plastic particles under 5 millimetres that come from industrial effluent, textiles, synthetic car tires, personal care products and other sources – have already been discovered inside fish, peppering Arctic sea ice, and in the snows on the Pyrenees mountains between France and Spain.However, the mechanisms of their transport to such varied locations had remained unclear, with research on airborne microplastic transport in particular being limited.