New Delhi: You must be aware of acid rain, but have you ever heard of plastic snow? An international team of researchers is investigating how much plastic is trickling down on us from the atmosphere, and is deposited on snow.


The study, conducted by Dominik Brunner from the Swiss Federal Laboratories for Materials Science and Technology (EMPA), Switzerland, and other researchers from the Utrecht University in Netherlands, and the Austrian Central Institute for Meteorology and Geodynamics, was recently published in the journal, Environmental Pollution. The researchers documented a bizarre phenomenon of plastic snow in their study.


Around 43 Trillion Miniature Plastic Particles Land In Switzerland Each Year


Some nanoplastics travel over 2,000 kilometres through the air, according to the study. About 43 trillion miniature plastic particles land in Switzerland every year, according to the figures from the measurements made in the study. 


The recent estimates from the study suggest that around 3,000 tonnes of nanoplastics cover Switzerland every year, from the remote Alps to the urban lowlands. The estimates are very high compared to other studies, and more research is needed to verify the numbers, the authors noted in the study. 


The spread of nanoplastics through the air is still largely unexplored. The result of Brunner's research is the most accurate record of air pollution by nanoplastics ever made, according to the study. Brunner and his colleagues developed a chemical method that determines the contamination of the samples with a mass spectrometer, to count the plastic particles.


Huge Concentration Of Plastics In Snow


The researchers studied a small area at an altitude of 3,106 metres at the top of the mountain "Hoher Sonnenblick" in the "Hohe Tauern" National Park in Austria, the study said. Since 1886, an observatory of the Central Institute for Meteorology and Geodynamics has been located in the mountain. 


The scientists used the research station to study the spread of nanoplastics in remote areas. They removed a part of the top layer of snow around a marker at 8 am every day, and in all weather conditions. Then, they carefully stored it.


The average nanoplastics concentration was 46 nanograms per millilitre of melted surface snow, according to the study. The calculated deposition rate at the snow surface was 42 kilograms per square metre per year, the study said.


Therefore, more than 2 × 10¹¹ nanoplastics particles are deposited per square metre of surface snow each week of the observed period, even at the remote location. This raises significant toxicological concerns, the authors noted in the study.


One of the challenges during the study was to avoid contamination of the samples by nanoplastics in the air or on the scientists' clothes. 


With the help of the European wind and weather data, the scientists traced the origin of the tiny particles, the study said. The greatest emission of nanoplastics into the atmosphere occurs in densely populated, urban areas, the researchers found.


Where Do The Plastics Come From?


Around 30 per cent of the nanoplastic particles measured on the mountain top snow originates from a radius of 200 kilometres, mainly from cities, the study said. However, the spray of ocean's waves also makes the plastics from the world's oceans into the air. Wind and weather blew around 10 per cent of the particles measured in the study onto the mountains over 2,000 kilometres. Some of the particles were from the Atlantic, according to the study.


Nanoparticles Can Affect The Human Body


More than 8,300 million tonnes of plastics are estimated to have been produced worldwide to date. Around 60 per cent of this is now wasted. 


Weathering effects and mechanical abrasion cause the waste to be eroded from macro- to micro- and nanoparticles, according to the study.


Discarded plastic is not the only source. Plastic products such as packaging and clothing, used on a day-to-day basis, release nanoplastics.


Tiny particles apart from plastics are also spread through air. Nanoparticles are sucked deep into the lungs through respiration, unlike microparticles, which only end up in the stomach. In the lungs, the size of nanoparticles may allow them to cross the cell-blood barrier and enter human bloodstream, the study said.