Part 3 - 3_text.pdf

MATTER ENVIRONMENT You Are Made of Waste Searching for the ultimate example of recycling? Look in the mirror BY CURT STAGER YOU MAY THINK OF YOURSELF asa highly refined and sophisticated creature—and you are. But you are also full of discarded, rejected, and recycled atomic elements. Don’t worry, though—-so 1s almost everyone and everything else. Carbon: Your inky nails Look at one of your fingernails. Carbon makes up half of its mass, and roughly 1 in 8 of those carbon atoms recently emerged from a chimney or a tail- pipe. Coal-fired power plants, petroleum-guzzling cars, and kitchen gas stoves release carbon dioxide into the atmosphere. Each of those waste molecules is a carbon atom borne on two atomic wings of oxy- gen. Fossil-based carbon dioxide molecules that are not soaked up by the oceans or stranded m the upper atmosphere are eventually captured by plants, shorn of their oxygen wings, and woven into botanical sug- ars and starches. Eventually, some of them end up in bread, sweets, and vegetables, while others help form carbon-rich animal tissues, finding their way into meat and dairy products. Historically, atmospheric carbon dioxide was mainly replenished by volcanoes, forest fires, and biotic respiration. Today, one quarter of atmospheric CO; is the result of fossil fuel combustion, whether it rose from smokestacks or was displaced from the oceans. (When fossil-fuel CO2 dissolves into ocean water, it displaces already-dissolved carbon dioxide derived from natural sources.) And because all of the carbon in your body derives from ingested organic matter, which in turn obtains it from the atmo- sphere, your fingernails and the rest of the organic matter in your body are built, in part, from emissions. ILLUSTRATIONS BY YUKO SHIMIZU 16