Hundreds of cases of bottled water are stored at Our Lady of Guadalupe Church in Flint, Mich. (AP/Carlos Osorio)

Lead contamination in drinking water is a problem that reaches far beyond the disaster in Flint, Mich., and threatens children’s health nationwide.

On Thursday, USA Today reported that “hundreds of schools across the nation” have lead-tainted water, exposing children to “excessive amounts of an element doctors agree is unsafe at any level.” The story relied on an analysis of Environmental Protection Agency data, which it said revealed that “about 350 schools and day-care centers failed lead tests a total of about 470 times from 2012 through 2015.”

“That represents nearly 20% of the water systems nationally testing above the agency’s ‘action level’ of 15 parts per billion,” according to the story.

The paper’s investigation echoes a report last month by Washington Post reporter Yanan Wang, who wrote that 12 states found “a greater percentage of kids under six years old met or surpassed” blood-lead levels of at least 5 micrograms per deciliter — the threshold requiring public health action, as defined by the federal government. “The most egregious example is Pennsylvania, where 8.5 percent of the children tested were found to have dangerously high levels of lead in their blood,” wrote Wang, who noted that such poisoning can be traced not just to water but to paint in old homes.

In New Jersey, a coalition led by a community development nonprofit, Isles, Inc., last month pressed New Jersey Gov. Chris Christie (R) to increase funding of a program to control lead after an analysis of state data found 11 cities had a higher proportion of children with dangerous lead levels than Flint.

“While lead levels in children in the suburbs have plummeted, the harsh fact is that minority children in urban communities continue to be poisoned,” Isles environmental health director Elyse Pivnick told Wang. “If you’re a mother in Trenton or Newark, we do not think the problem has been solved.”

Seven years ago, a study concluded that hundreds of young children in Washington, D.C., suffered potentially damaging amounts of lead in their blood because of contamination in the city’s tap water. The toxin can cause permanent developmental and behavioral issues.

The study contradicted the past public assurances of federal and D.C. health officials. In 2004, although officials conceded that the amount of lead in city water was at record levels, they said repeatedly that they found no measurable impact on the general public’s health.

Flint’s water was contaminated when a state-appointed emergency manager, in a cost-cutting move, switched the city’s water supply from the Detroit system to the Flint River. State environmental officials failed to ensure that anti-corrosive chemicals were added to the water, allowing lead to leach from aging pipes.

Michigan Gov. Rick Snyder (R) and EPA Administrator Gina McCarthy testified in front of the House Oversight Committee on March 17, and things got a little heated. (Peter Stevenson/The Washington Post)

Michigan Gov. Rick Snyder (R) acknowledges the state agency’s inaction, but he also blames the Environmental Protection Agency for failing to do due diligence in protecting Flint residents as they began to raise concerns about their tap water. In a House oversight committee Thursday, EPA Administrator Gina McCarthy put the responsibility squarely back on the state, as Post reporter Lenny Bernstein reported.

“The crisis we’re seeing was the result of a state-appointed emergency manager deciding that the city would stop purchasing treated drinking water and instead switch to an untreated source to save money,” McCarthy said. “The state of Michigan approved that decision.”

Lead poisoning has a variety of sources, nearly all of them household items. The most common source of is peeling paint in older houses or apartment buildings. David Rosner, a public health and history professor at Columbia University and the author of “Lead Wars,” told The Post’s Philip Bump that lead was a once considered a “gift of God,” a statement attributed to a General Motors representative in the early 20th century, when industrialists considered it “essential to modern production.”

The full scope of lead contamination in public drinking water may be impossible to determine. As the USA Today story notes, the federal government only requires about one in 10 schools to test for it.

Read more at Energy & Environment:

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