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The trouble with nurdles

2007; Wiley; Volume: 5; Issue: 7 Linguagem: Inglês

10.1890/1540-9295(2007)5[396

1540-9309

Katherine Ellison,

Global Energy and Sustainability Research

“Nurdle” is a word that sneaks up on you. At first it sounds diminutive and cuddly, and maybe even edible – a type of pasta? Learn more, however, and you may lose your appetite. Nurdles are tiny plastic pellets used in manufacturing and packaging. Cylindrical or tear-shaped, and up to 5 mm in diameter, they're too small to be filtered out by most US sewage systems. And so, increasingly, they wind up in the ocean, swept into waterways from factory drains or during transportation by truck or train. There, nurdles combine with the tons of other plastic debris that have transformed the world's seas in just the past 50 years – a time of soaring plastic production and, mostly, thoughtless disposal. An estimated 60 billion pounds of nurdles are now made each year in the US alone. For marine life, nurdles can be poison pills. They look like fish eggs, yet soak up and concentrate toxic pollutants such as polychlorinated biphenyls (PCBs). Tokyo University geochemist Hideshige Takada has found that plastic pellets eaten by birds concentrate toxic chemicals to as high as one million times their normal levels in seawater. Of course, birds aren't the only victims. At the University of Ply-mouth, marine biologist Richard Thompson points out that nurdles and other plastic trash inevitably break down, through the force of tides and ultraviolet light, into ever-tinier fragments. He has found some pieces as small as 20 microns – smaller than a human hair – which are easily consumed by some of the sea's most diminutive creatures. He assumes the plastic bits, which decompose but don't ever biodegrade, are eventually ground down into powder, which can be swallowed even by zooplankton. Scientists have yet to pinpoint the impact on the marine food web or on people who eat fish that have eaten nurdles and other nurdle-eaters. But I think it's fair to say that it doesn't look good for those of us at the top of the food chain. Another leader in the field has been Charles Moore, founder of the California-based Algalita Marine Research Foundation. In recent years, Moore has compared the weight of ocean-borne plastic fragments and biomass of zooplankton, with startling results. His papers in the Marine Pollution Bulletin reveal that the plastic outweighs the plankton 6 to 1 in the central Pacific, and 2.5 to 1 in the surface waters of Southern California. Among our myriad modern environmental blights, plastic debris in the sea is a fairly recent worry. Yet both the blight and the worry have grown quickly enough to prompt a response from some politicians. In what advocates claim is the world's first legislative effort to curb the use of nurdles, a bill (AB 258) requiring nurdle users to adopt stronger house-keeping measures has been moving through California's state legislature this summer. The bill could require industry to load and unload nurdles in covered, enclosed areas, use vacuum equipment on site, and put screens over the intakes of storm drains. California's Lieutenant Governor, John Garamendi, has even called for funding of a new nurdle police, who might enforce existing civil penalties under the federal Clean Water Act. Meanwhile, Santa Monica and San Francisco have banned styrofoam for restaurant take-out, while San Francisco recently became the first US city to ban plastic bags. I confess I've been holding out hope that biodegradable materials may soon effectively replace long-lived plastic. But Thompson's research throws cold water on science's achievements in developing such materials. As Alan Weisman recounts in his new book, The world without us, Thompson's tests of purportedly biodegradable plastic show them to be a mixture of cellulose and polymers. Once the cellulose starch breaks down, thousands of clear, nearly invisible plastic particles remain. Thompson is now working to organize a meeting between policy makers and leading scientists studying the marine plastic problem to map out an agenda for future research. “The problem is that the topic is multidisciplinary”, he explained to me in an e-mail. “It stretches from polymer chemistry, through marketing, economics, sociology, ecology, pollution, environmental chemistry, human health, sustainability, and ultimately back to polymer chemistry – recycling.” Should we seek to live in a world without plastic? Thompson, to my surprise – since he is so immersed in the disturbing consequences of a world with far too much of it – says no. Reducing, reusing, and recycling is the answer, he suggests, adding that he'd support a ban on those billions of plastic bottles with non-recyclable caps. “Plastic is actually a pretty good material”, he concludes. “It's people who are the problem.”