When Mark Browne set out to study the plastic waste that litters the oceans, he hadn’t planned on doing laundry in the name of science. Browne, an ecologist at the University of New South Wales, Australia, was aiming to chart the quantities and types of plastic fragments washing up on shores worldwide. Five years ago, he and his colleagues had already found a surprisingly large amount of nylon and polyester fibers, particularly near heavily populated areas. When they sampled sewage effluent, as well as decades-old sewage dumps, Browne and his colleagues found the same range of fibers, in exactly the same proportions of polymers used by the clothing industry.
So Browne set up three washing machines and began running synthetic blankets, shirts, and sweaters through the spin cycle, testing the water that drained out of the machines. “Our water footprint was probably huge,” he says, “but the amounts [of fibers] we detected were alarming.” Garments such as fleeces shed up to 1,900 tiny fibers every time they were washed. Too small to be filtered out of the sewage system, the fibers would eventually find their way to open water, Browne says.
[Read more at PNAS Front Matter // May 5, 2015 ]