A University of Utah study used human hair to track changes in lead exposure across about 100 years. Researchers collected samples from 48 individuals along the Wasatch Front, including modern hair and older strands preserved in family scrapbooks dating to 1916. The area once hosted smelting plants in Midvale and Murray that produced heavy local emissions.
The team analysed the hair with mass spectrometry at a university facility directed by Diego Fernandez. Hair can hold elements on its surface, and the method is sensitive enough to measure lead in a single hair strand. However, blood gives a better measure of recent internal exposure, while hair preserves older exposure.
The study, published in PNAS, reports dramatic reductions after environmental regulations. The authors link much early exposure to leaded gasoline and say regulation helped cut population exposure. Coauthor Thure Cerling and demographer Ken Smith said the findings show the value of regulation.
Difficult words
- smelting plant — factory where metal ore is heated and meltedsmelting plants
- emission — polluting substance released into the airemissions
- mass spectrometry — laboratory method to measure chemical elements
- exposure — condition of being in contact with a substance
- preserve — kept safe for later use or studypreserved
- regulation — official rule to control behaviour or activityregulations
- demographer — person who studies population size and trends
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- Do you think using hair from old family scrapbooks is a valid way to study past pollution? Why or why not?
- How do the study findings show the value of environmental regulations for public health?
- What local sources of pollution in your area could increase lead exposure, and what could reduce them?
