Plastic rain: How the tiny particles end up in clouds
Explainers
By
Mactilda Mbenywe
| Oct 22, 2023
There are microplastics in cloud water and they have a direct impact on the changing climate, researchers have examined.
Microplastics are plastic particles less than 5 mm in size. They are often found in industrial effluents, or from the degradation of bulkier plastic waste.
Research shows that large amounts of microplastics are ingested or inhaled by humans and animals alike and have been detected in multiple organs such as the lungs, heart, blood, placenta, and faeces.
Ten million tons of these plastic bits end up in the ocean, are released with the ocean spray, and find their way into the atmosphere. This implies that microplastics may have become an essential component of clouds, contaminating nearly everything we eat and drink via "plastic rainfall".
In a new study published in the journal Environmental Chemistry Letters led by Hiroshi Okochi, Professor at Waseda University, a group of Japanese researchers has explored the path of airborne microplastics (AMPs) as they circulate in the biosphere, adversely impacting human health and the climate.
The team collected cloud water from the summit of Mt Fuji, the 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 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.
Scientists found tiny bits of broken plastic called polypropylene in the cloud samples. These pieces were very tiny, between 7.1 to 94.6 micrometres. They also discovered plastic particles in the clouds that like water, help clouds form quickly. This suggests that these plastic bits might be changing how clouds form, which impacts the climate.