Scientists collected hair from people who lived along the Wasatch Front in Utah. They used both recent samples and older strands kept in family scrapbooks that go back to 1916. The region once had smelting plants that made a lot of local pollution.
The team analysed the hair with mass spectrometry at a university lab. Hair can keep lead on its surface, so it preserves older exposure. The researchers found large declines in hair lead after the United States began regulating lead in the 1970s.
Difficult words
- smelting — process that gets metal out of rock
- pollution — harmful material in air, water or soil
- mass spectrometry — laboratory method to measure chemicals and particles
- exposure — contact with something dangerous or harmful
- regulate — to make and control official rules or limitsregulating
- scrapbook — book where people keep old photos and papersscrapbooks
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- Why were old hair samples in family scrapbooks important for this study?
- What change did researchers see in hair lead after the 1970s?
- Do you have old family items like scrapbooks? What can they tell about the past?
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