Holy micro! Plastic bits found on pristine mountains. How?
SA scientists’ shocking findings and their implications have reverberated around the world
Microplastic pollution has been found at a remote site on the top of the Pyrenees mountains, according to a shocking new study by two formerly Nelson Mandela Bay-based scientists.
The findings of the study by Steve and Dr Deonie Allen are the first evidence that microplastics are being transported and deposited across the planet by wind, rain and snow.
The study was published on Monday in the London-based Nature Geoscience journal, sparking immediate interest internationally, and by the end of the day the Allens had already fielded 20 pre- and post-publishing interviews.
Responding to questions from Toulouse, in France, where they are currently based, Steve Allen said the study findings pointed to huge possible ramifications for plastic pollution.
“Nature does not see borders. It is entirely possible that microplastic from one area could reach anywhere in South Africa, for instance.”
Waste plastics never decompose completely, and instead they break up into increasingly tiny fragments, which have become a major global pollution concern.
The Allens undertook the study in Bernadouze, a pristine site near the source of the Ariege River at the summit of the French Pyrenees, through the northern hemisphere winter of 2017/18.
Two studies in Paris and Dongguan, in China, had already recorded the large-scale presence of microplastics, but it was assumed that this was a phenomenon of those megacities, and atmospheric transport of this pollution had not yet been shown.
They installed two “deposition samplers”, funnels to capture rain, snow and dust and channel it into a bottle, and then picked out the microplastics using a special staining fluid and a fluorescence microscope, he said.
“The staining liquid sticks to plastic very well, and the microscope hits it with short wavelength light to excite the stain.
“We had been expecting to find some particles of plastic, but we were seriously shocked at the numbers.
“This meant substantial amounts of plastic could be floating around in our air with the potential of getting anywhere.
“What we had was the first confirmation of atmospheric transport of microplastics via wind, rain and snow.”
It was already known that microplastics were widely present in tap water, and this was clearly one way it was getting into water supplies, he said.
It was highly unlikely the particles came from the villages around Bernadouze, as these were mostly home to just five or six hundred people. Furthermore, back-trajectory modelling using prevailing weather factors showed no likely sources for plastic pollution less than 95km away.
“The particles were in quantities approximating what had been found in Paris and Dongguan, and big cities seem like the most likely sources.”
The comparative numbers for microplastics found in these cities and in Bernadouze were key, he said.
“It suggests that microplastic pollution from cities, the likely sources, can affect even the most pristine areas.”
The majority of the Bernadouze particles seemed to be coming from the direction of Toulouse and Paris, but they were not able to prove this, he said.
“This may be possible, but it would require further monitoring analysis – and this is highly recommended.”
The Allens, who have been working on microplastic pollution with Nelson Mandela University and who are hoping to return to the Eastern Cape, said alarm bells had already sounded on the link between microplastic pollution and human health.
“As far back as 1998, a study of the National Centre of Biotechnology Information in the US found plastic fibres in human lungs. The study showed that 80% of lungs had fibres and 97% of lung tumours contained fibres,” Steve said.
“There are also currently several new studies under way to determine the risks associated with inhaling and eating microplastics.”