Think of plastic pollution in the world’s oceans and visions of the Great Pacific Garbage Patch invariably come to mind. But an emerging breed of “microplastics,” defined as any plastic particle smaller than 1 nanometer—or one hundred-thousandth the width of a human hair—is raising health and safety concerns on shorelines across the globe. Unlike its larger brethren, however, microplastic pollution has a far more insidious cause. And, according to a study published in the November 1, 2011 issue of Environmental Science & Technology, our washing machines are partly to blame.
Microscopic fragments of acrylic, polyethylene, polypropylene, polyamide, and polyester have been discovered in increasing quantities across the northeast Atlantic, as well as on beaches in Britain, Singapore, and India, says Mark Browne, an ecologist at University College Dublin and the paper’s lead author. Browne and his colleagues from the University of Sydney in Australia, the Universities of Plymouth and Exeter in the United Kingdom, and Waters in Canada sampled 18 sites representing shorelines in six continents to track down a possible source of the contamination.
A chemical analysis revealed that nearly 80 percent of the filaments comprised polyester or acrylic, which are common in synthetic textiles.
By separating the plastic from the sand and chemically analyzing them, the researchers discovered that nearly 80 percent of the filaments were either polyester or acrylic, both of which are common in synthetic textiles. No single beach was devoid of the colorful lint. Each cup of sand had at least two fibers and as many as 31. The most-contaminated samples also originated from areas with the highest human population density, suggesting a pathway to the ocean through sewage. Samples of treated wastewater and sewage-tainted ocean sediment confirmed the scientists’ suspicions.