Researchers in Japan have confirmed that microplastics are present in clouds, where they are likely affecting the climate in ways that are not yet fully understood.
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.
To investigate the role of these tiny plastic particles in the troposphere and the atmospheric boundary layer, the team collected cloud water from the summit of Mount (Mt.) Fuji, south-eastern foothills of Mt. Fuji (Tarobo), and the summit of Mt. Oyama – regions at altitudes ranging between 1300-3776 meters. Using advanced imaging techniques like attenuated total reflection imaging and micro-Fourier transform infrared spectroscopy (µFTIR ATR imaging), the researchers determined the presence of microplastics in the cloud water, and examined their physical and chemical properties.
They identified nine different types of polymers and one type of rubber in the AMPs detected. Notably, most of the polypropylene that was detected in the samples was degraded and had carbonyl (C=O) and/or hydroxyl (OH) groups. The Feret diameters of these AMPs ranged between 7.1 – 94.6 µm, the smallest seen in the free troposphere. Moreover, the presence of hydrophilic (water loving) polymers in the cloud water was abundant, suggesting that they were removed as “cloud condensation nuclei.” These findings confirm that AMPs play a key role in rapid cloud formation, which may eventually affect the overall climate.
Accumulation of AMPs in the atmosphere, especially in the polar regions, could lead to significant changes in the ecological balance of the planet, leading to severe loss of biodiversity. Okochi concludes by saying “AMPs 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. As a result, the findings of this study can be used to account for the effects of AMPs in future global warming projections.”
The University of Newcastle study, which was commissioned by WWF, found that the average person consumes around 2000 tiny pieces of plastic each week, or about 5 grams, which equates to the weight of the average credit card. Researchers compiled data from over 50 microplastic studies to determine the average quantity of the tiny plastics found in food and drink staples like water, fish, sugar, beer, and salt.
“Given that in this study the microplastics were delivered orally via drinking water, detection in tissues such as the gastrointestinal tract, which is a major part of the digestive system, or in the liver and kidneys was always probable,” Ross said. “The detection of microplastics in tissues such as the heart and lungs, however, suggests that the microplastics are going beyond the digestive system and likely undergoing systemic circulation. The brain-blood barrier is supposed to be very difficult to permeate. It is a protective mechanism against viruses and bacteria, yet these particles were able to get in there. It was actually deep in the brain tissue.”
That brain infiltration also may cause a decrease in glial fibrillary acidic protein (called “GFAP”), a protein that supports many cell processes in the brain, results have shown. “A decrease in GFAP has been
associated with early stages of some neurodegenerative diseases, including mouse models of Alzheimer’s disease, as well as depression,” Ross said. “We were very surprised to see that the microplastics could induce altered GFAP signaling.”
She intends to investigate this finding further in future work. “We want to understand how plastics may change the ability of the brain to maintain its homeostasis or how exposure may lead to neurological disorders and diseases, such as Alzheimer’s disease,” she said.



AMP is Airborne Microplastic Particles
https://youtu.be/rld0KDcan_w?si=SGadOThOUqK7sC5T
Minor point: the plastics are attached to the moisture that make up the clouds. The water in the air. Some reporting has the plastics “in the atmosphere” ~ technically correct I guess but not exactly. Still “in the water … ”
I think this the more accurate marker for the turn of the Anthropocene