The municipal water crisis in Flint, Mich., has brought new attention to the dangers of lead in drinking water.
When the city starting using the Flint River as its source for municipal water in 2014, the water was so corrosive, it caused lead to leach out of pipes and fixtures.
But experts say this is just the latest example in a long history of lead contamination in the U.S.
“One of the most famous examples is in Lowell, Massachusetts,” said Werner Troesken, an economist at the University of Pittsburgh and author of The Great Lead Water Pipe Disaster.
“In the 1890s, they changed a water supply, as in Flint, and suddenly, adults started coming down with obvious symptoms of lead poisoning. And local doctors were initially dumbfounded." They asked, "'Where is all this lead coming from?'”
Troesken said there were multiple cases where — for years — people were found to be drinking water that contained lead levels that were 1,300 times greater than current EPA standards. That lead exposure had a lasting impact.
“What we’re able to do is link people across censuses," he said. "If you grew up in a place with a lot of lead, there are large, long-term effects on your economic outcomes. You earn less. You get less educational attainment. The long-term effects are serious and difficult to document.”
According to the EPA, lead exposure in children is correlated with lower IQ and learning problems. In Flint, community groups are seeking donations to the Flint Child Health and Development Fund to help with the short and long-term effects on Flint’s children. A lawsuit filed by several citizen groups also seeks “appropriate relief” to handle medical issues associated with the crisis.
Exposure may impact generations
Researchers with the Centers for Disease Control and Prevention report that roughly half a million American children have elevated levels of lead in their blood. Kids can get exposed to lead through drinking water or by ingesting dust in older homes with lead-based paint. And babies can be exposed to lead while they’re still in utero.
Studies consistently show lead exposure can cause permanent brain damage and hyperactivity in children. But a recent study suggests it can cause changes to DNA that might affect several generations.
“If the mothers had high blood lead levels when they were born, then their grandchildren have changes in their DNA,” said Doug Ruden, co-author of the study and director of epigenomics at the Institute of Environmental Health Sciences at Wayne State University.
“And the changes in the DNA we we're looking at weren’t mutations; they weren’t permanent changes. They’re what we call epigenetic mutations.”
Epigenetic mutations are those that affect how genes express themselves in a person. And that could explain the problems children have when they’re exposed to lead.
Ruden’s research also suggests lead exposure has the potential to affect several generations. He said they’re looking at how exposures during pregnancy can affect not just the baby a mom is carrying, but also her grandchildren.
Ruden’s study looked at 35 mothers and their babies in Detroit.