NAUTILUS EDUCATION
BETA PRODUCT
Radioactive Carbon-14: Your pearly whites
When you smile, the gleam of your teeth obscures a slight glow from radioactive waste. During the late 1950s and early 1960s, atmospheric testing of thermo- nuclear weapons scattered so much radioactive car- bon-14 into the atmosphere that 1t contaminated vir- tually every ecosystem and human. Several thousand unstable radiocarbon atoms explode within and among your cells every second as their unstable nuclei under- go spontaneous radioactive decay. Some are the natu- ral products of cosmic rays that can turn atmospheric nitrogen into carbon-14, while others result from the decay of unstable mineral elements that are found in soil. But many of them represent the echoes of ther- monuclear airbursts from the Cold War, finding their
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way into our water supply and meals. If they happen to disintegrate within your DNA, they can damage your genes. And many of them are bound up in your teeth. Unlike most of the atoms in your body, those embed- ded in your strong, stable tooth enamel have been with you ever since you ingested them through your umbili- cal cord and your infant feeding. If you were born dur- ing the early 1960s, you have more nuclear waste in your teeth than if you were born later, when soils and oceans had had time to bury radioactive atoms. In fact, forensic scientists use the proportion of bomb carbon in tooth enamel to determine the age of unidentified human remains.
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