Microplastics found in clouds for the first time

Researchers in Japan have discovered microplastics in clouds, where they might be affecting the climate in ways that aren’t yet fully understood.

As detailed in a study published in Environmental Chemistry Letters, scientists from Waseda University climbed Japan’s Mount Fuji and Mount Oyama, at altitudes between 1,300 and 3,776 metres, in order to collect water from the surrounding clouds, and then applied advanced imaging techniques to the samples to determine their physical and chemical properties.

The testing found nine different types of polymers and one type of rubber in the airborne microplastics. In detail, each litre of cloud water contained between 6.7 to 13.9 pieces of microplastic, the scientists wrote, ranging in size from around 7 to 95 micrometres; slightly over the average width of a human hair at 80 micrometres.

“To the best of our knowledge, this is the first report on airborne microplastics in cloud water,” the authors wrote in their paper.

The scientists found an abundance of hydrophilic (or water-loving) polymers, which they said might act as “cloud condensation nuclei” – suggesting they play a key role in rapid cloud formation, which could affect the overall climate.

“Overall, our findings suggest that high-altitude microplastics could influence cloud formation and, in turn, might modify the climate…[since airborne microplastics] are degraded much faster in the upper atmosphere than on the ground due to strong ultraviolet radiation, and this degradation releases greenhouse gases and contributes to global warming,” they wrote.