The Highest Microplastic Air Pollution Award Goes to London

Millions of pieces of microplastic are raining in London every day, a replacement study suggests.

Researchers at King's College London, whose study was published in Environment International, analyzed the number of particles and fibers falling on to the roof of a nine-story building within the middle of London, on eight separate days.

They picked a spot high to make sure that only microplastic from the atmosphere was collected, instead of pieces being deposited daily at ground level.

Tiny pieces of plastic were found eight samples altogether, with numbers starting from 575 to 1,008 per square meter (10.7 square foot) every day. If an equivalent amount was falling across the capital, it suggests many pieces of plastic fall in London every day.

Previous studies have shown that microplastic can travel great distances within the air, with pieces discovered within the most remote locations, like the Arctic and, therefore, the tops of mountains.

Tap water is additionally known to contain microplastics, with the new study suggesting the pollutants could also be falling from the sky, and becoming trapped within the water cycle.

The accumulation rate in London was found to be 20 times above in Dongguan, China, seven times above in Paris, France, and nearly three times above Hamburg, Germany, which are the sole other cities where similar measurements are taken. 

"We found [an excessively high amount] of microplastics," lead researcher Stephanie Wright, of King's College, told The Guardian.

The study showed that microplastic deposition was consistent despite the strength or direction of the wind, suggesting most of the pollution originated in the city itself.

Further studies of the microplastics revealed that the majority were fibers made from acrylic, probably from clothing. Fewer than 10 percent were particles, and these were mostly polystyrene and polyethylene, which are primarily found in food packaging.

The impact of inhaling or ingesting microplastics remains unknown. However, most airborne pollution is bad for health and has been linked to heart problems, dementia, depression, asthma, bronchitis, and even cancer.

The microplastic particles found in London were between 0.02mm and 0.5mm, which make them large enough to be deposited on to the airways when inhaled and that they could also easily be swallowed. 

Some studies have suggested that folks could also be ingesting 50,000 tiny plastic particles a year, through beverage, consuming seafood or accidentally eating bits of packaging, and last year, scientists in Austria found microplastics within the stools of humans for the first time. 

On average, the researchers found 20 microplastic particles per 10g of body waste, and scientists fear that plastics contain toxic chemicals or carry harmful microbes.

Melanie Bergmann, at the Alfred Wegener Institute for Polar and Marine Research in Germany, said more research on the potential health effects of microplastic pollution was very important.

Bergmann said there are no exact proportions yet of inhaled microplastics enter in the deep lung. In a report in April, the European commission's chief scientific advisers said the proof on the environmental and health risks of microplastics presents areas for genuine concern and for precaution to be executed.