A Century of Hair Holds the Answer to Declining Lead Exposure
Researchers have been studying an unlikely source to understand the trend of declining lead exposure: human hair. A recent study published in PNAS analyzed hair clippings from Utahns dating back to 1916, revealing a stark difference in lead levels before and after the creation of the Environmental Protection Agency (EPA).
The results are nothing short of striking. Lead levels in Utah's Wasatch Front were approximately 100 times higher in 1916 than they are today, with the concentration dropping dramatically following the EPA's establishment in 1970. The shift towards phasing out lead from products like pipes, paint, and gasoline is undoubtedly a key factor behind this decline.
"We can show through our hair samples what the lead concentrations were before and after regulations by the EPA," said Ken Smith, demographer at the University of Utah. "It's incredible how much of an impact those regulations have had on public health."
The researchers used mass spectrometry to analyze the hair samples, which proved to be a valuable tool in pinpointing chemical compounds like lead. While blood would provide more insight into individual exposure, hair is simpler to work with and offers a window into past exposures.
According to Diego Fernandez, co-author of the study, "the surface of the hair is special... Lead is one of those elements that gets concentrated and accumulated on the surface." This made it easier for the researchers to detect lead in their samples, even with limited hair samples.
The results are also consistent with a broader trend: despite increased use of gasoline in the 1970s, lead levels plummeted. The EPA's regulations had a profound impact, and it's unlikely that coincidence played a role.
"This study is a reminder of the importance of environmental regulations," said Thure Cerling, co-author and professor at the University of Utah. "Those regulations may seem onerous, but they've had incredibly positive effects on public health."
The study comes as the EPA faces budget cuts, with its current funding 54% lower than in 2025. However, this decrease should not obscure the significance of research like this, which highlights the crucial role that environmental protections have played in reducing lead exposure over the past century.
Researchers have been studying an unlikely source to understand the trend of declining lead exposure: human hair. A recent study published in PNAS analyzed hair clippings from Utahns dating back to 1916, revealing a stark difference in lead levels before and after the creation of the Environmental Protection Agency (EPA).
The results are nothing short of striking. Lead levels in Utah's Wasatch Front were approximately 100 times higher in 1916 than they are today, with the concentration dropping dramatically following the EPA's establishment in 1970. The shift towards phasing out lead from products like pipes, paint, and gasoline is undoubtedly a key factor behind this decline.
"We can show through our hair samples what the lead concentrations were before and after regulations by the EPA," said Ken Smith, demographer at the University of Utah. "It's incredible how much of an impact those regulations have had on public health."
The researchers used mass spectrometry to analyze the hair samples, which proved to be a valuable tool in pinpointing chemical compounds like lead. While blood would provide more insight into individual exposure, hair is simpler to work with and offers a window into past exposures.
According to Diego Fernandez, co-author of the study, "the surface of the hair is special... Lead is one of those elements that gets concentrated and accumulated on the surface." This made it easier for the researchers to detect lead in their samples, even with limited hair samples.
The results are also consistent with a broader trend: despite increased use of gasoline in the 1970s, lead levels plummeted. The EPA's regulations had a profound impact, and it's unlikely that coincidence played a role.
"This study is a reminder of the importance of environmental regulations," said Thure Cerling, co-author and professor at the University of Utah. "Those regulations may seem onerous, but they've had incredibly positive effects on public health."
The study comes as the EPA faces budget cuts, with its current funding 54% lower than in 2025. However, this decrease should not obscure the significance of research like this, which highlights the crucial role that environmental protections have played in reducing lead exposure over the past century.
. The fact that it was 100 times higher in 1916 than today is wild. And the part about lead accumulating on the surface of hair? Mind blown 
. It just goes to show how crucial regulations have been for public health. I'm all for environmental protections, no matter what the haters say 
. Let's keep the momentum going and make sure we're still prioritizing those regulations 
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. Scientists are studying hair clippings to see how lead levels dropped after EPA regulations came into play 
. It's crazy how much of a difference a simple rule change made for our health 
.
. It's crazy to think that the EPA even existed back then! Anyway, this study is like, totally awesome. Using human hair as a source to figure out declining lead exposure? Genius! I mean, it makes sense that regulations would make a difference, but still, 100 times lower levels in 2025 compared to 1916? That's just wild 
and using hair samples to track changes is genius 
mass spectrometry is like, whoa tech 
but what's even more amazing is how the concentration of lead accumulated on the surface of our hair 
and this study is a major reminder that environmental protections are still super important 
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. The EPA's job isn't done, and it's up to us to keep pushing for more progress on these issues 
I think it's pretty cool how scientists are using hair samples to track down the decline of lead levels over time. It makes sense, given that blood tests can be invasive and don't give us a complete picture of someone's exposure history. Using hair is like getting a snapshot of past exposures - you can see the gradual shift in lead levels as regulations changed. It's also reassuring to know that all those efforts to phase out lead from products have paid off, with huge reductions in overall lead exposure. I'd love to see more research like this on other environmental issues and how we've improved our lives by reducing toxic substances! 
it's wild to think about how much hair can tell us about our environment. I mean, who knew your grandma's locks could hold so much info about air quality? 
I mean, it's wild to think about how much of a difference regulations can make. Like, literally having a agency dedicated to protecting the environment has led to a huge drop in toxic lead levels in hair samples from 100x higher back then to almost nothing today. It's all about those rules and laws that we have in place to keep us safe. You know, people say EPA cuts are bad but this study shows how much of a difference they've made already. And can you imagine if we didn't have any environmental protection? We'd be in some serious trouble. 
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