Some 74 million metric tons of microplastics, the equivalent of more than 3 million plastic bottles, are falling on Auckland yearly, new research finds.
These tiny plastic fragments — shed from car tires, synthetic fabrics, plastic bottles, and other products — make their way into the atmosphere, waterways, and the sea. Scientists suggested that ocean currents may be ferrying microplastics from afar, and that crashing waves off the coast of Auckland are casting these particles into the air. The particles pose a risk to public health, according to the paper, which follows on a recent study that found microplastics buried deep in the lungs of human cadavers.
For the new research, scientists gathered tiny plastic particles at two locations in Auckland, New Zealand’s largest city. They recorded a daily average of 4,885 airborne particles per square meter, a figure that far outstrips previous tallies of 771 in London, 275 in Hamburg, and 110 in Paris.
Researchers attributed the difference to more sophisticated measuring techniques, which allowed them to identify particles as small as one-hundredth of a millimeter. To track the smallest particles, scientists applied a dye that glowed under certain conditions. The findings were published in the journal Environmental Science & Technology.
“The smaller the size ranges we looked at, the more microplastics we saw,” Joel Rindelaub, a chemist at the University of Auckland and lead author of the study, said in a statement. The tiniest particles pose the greatest health risk as they can enter the bloodstream and build up in organs, including the testicles, liver, and brain, the paper said.
“Future work needs to quantify exactly how much plastic we are breathing in,” Rindelaub said. “It’s becoming more and more clear that this is an important route of exposure.”
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