Millions of pieces of microplastic are raining down on London each day, a new study suggests.
Researchers at King’s College London, analysed the number of particles and fibres falling on to the roof of a nine-storey building in the middle of the capital, on eight separate days.
They picked a spot high up to ensure that only microplastic from the atmosphere was collected, rather than pieces being deposited daily at ground level.
Tiny pieces of plastic were found in all eight samples, with numbers ranging from 575 to 1,008 per square metre (10.7 square foot) each day. If the same amount was falling across the capital, it suggests millions of pieces of plastic fall on London each day.
Previous studies have shown that microplastic can travel great distances in the air, with pieces discovered in the most remote locations, such as the Arctic and the tops of mountains.
Tap water is also known to contain microplastics, with the new study suggesting the pollutants may be falling from the sky, and becoming trapped in the water cycle.
The accumulation rate in London was found to be 20 times higher than in Dongguan, China, seven times higher than in Paris, France and nearly three times higher than Hamburg, Germany, which are the only other cities where similar measurements have been taken.
We found a high abundance of microplastics, lead researcher Stephanie Wright, of King’s College, told The Guardian.
I find it of concern that is why I am working on it, she said. “The biggest concern is we don’t really know much at all. I want to find out if it is safe or not.
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 most were fibres made of acrylic, probably from clothing. Fewer than 10 per cent were particles, and these were mostly polystyrene and polyethylene, which are largely found in food packaging.
The impact of inhaling or ingesting microplastics is still unknown although 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 big enough to be deposited on to the airways when inhaled and they could also easily be swallowed.
Some studies have suggested that people may be ingesting 50,000 tiny plastic particles a year, through drinking water, consuming seafood or accidentally eating bits of packaging and last year scientists in Austria found microplastics in the stools of humans for the first time.
On average, the researchers found 20 microplastic particles per 10g of human waste and scientists fear that plastics contain toxic chemicals or carry harmful microbes.
The research was published in the journal Environment International.