Research groups such as Waseda University, Toyo University, and PerkinElmer Japan G.K. are the first in the world to demonstrate the existence of atmospheric microplastics through field observations of small water droplets and cloud water suspended in the air. Elucidate the origin.It became clear that environmental and health risks are increasing more than expected.
Atmospheric microplastics (AMPs) degrade at high altitude due to strong ultraviolet rays, and may release greenhouse gases such as methane and carbon dioxide, and promote cloud formation as cloud condensation nuclei or ice crystal nuclei. There isSo far, field observations have detected AMPs in rainwater, but the existence of AMPs in cloud water has not been proven.
Therefore, the research group investigated the summit of Mt. Fuji (elevation 2 m) located in the free troposphere (atmospheric layer above about 2.5-3,776 km), the southeastern foot of Mt. Fuji (elevation 1,300 m) located in the atmospheric boundary layer, 1,252 cloud water samples were collected from 2021 to 2022 at an altitude of 44m).
As a result, a total of 3 AMPs, or 70 types of AMPs, were detected from cloud water at 9 locations.AMPs with hydrophilic groups such as carbonyl groups, such as polyethylene terephthalate, polyamide 6, and polycarbonate, were concentrated in cloud water.Also, polyethylene and polypropylene, which originally do not have hydrophilic groups, have hydrophilic groups such as carbonyl groups and hydroxyl groups due to the progression of ultraviolet degradation.As a result, it became clear that there is a high possibility of functioning as cloud condensation nuclei or ice crystal nuclei.
If AMPs are cloud-forming, they scatter more sunlight, affecting the radiation budget, altering rainfall distribution, and possibly contributing to climate change.There are also concerns about health risks due to "plastic rain" polluting water sources and being ingested through agriculture and livestock.In the future, it will be important to further accumulate knowledge on the abundance of AMPs and their environmental and health risks.
Paper information:[Environmental Chemistry Letters]Airborne hydrophilic microplastics in cloud water at high altitudes and their role in cloud formation
