(Melina Mara/The Washington Post)

Hillary Clinton, speaking at Al Sharpton’s National Action Network in Harlem today, vowed to try to eliminate lead as a public health threat in only five years:

“What happened in Flint would have never happened in a wealthy suburb of Detroit. It’s no coincidence that black children are twice as likely as white children to suffer from asthma, three times more likely to be hospitalized, and five times more likely to die from the disease…

“Children of color are more likely than white kids to suffer lead poisoning, which can lead to lifelong learning challenges…it’s no coincidence that nearly half of all Latinos in the United States live in places where the air does not even meet EPA public health standards or that race is the single biggest factor determining whether you live near a toxic site…climate change is going to make the burden even heavier.

“So today I’m announcing a new plan to fight for environmental justice….I want to set an ambitious national goal to eliminate lead as a major public threat within five years.”

The details are here: The proposal on lead in particular includes a promise to establish a Presidential Commission on Childhood Lead Exposure, which would be charged with “writing a national plan to eliminate the risk of lead exposure from paint, pipes, and soil within five years.” It also includes a vow to push for $5 billion to implement the commission’s recommendations, to “replace lead paint, windows, and doors in homes, schools, and child care centers and remediate lead-contaminated soil.” It also references a separate $275 billion plan for infrastructure modernization that includes “drinking and wastewater infrastructure.”

Public health problems such as this one historically attract widespread notice when there are glaringly awful outbreaks of it that command media and public attention, such as the one in Flint, Michigan. But in fact, a national effort along the lines of the one Clinton is suggesting has long been sought by advocates for reform — because this remains a national problem that afflicts other cities and localities, too. As the New York Times recently put it:

By the most recent estimate, about 37 million homes and apartments still have some lead paint on walls and woodwork, 23 million with potentially hazardous levels of lead in soil, paint chips or household dust.

The Centers for Disease Control and Prevention estimate that four million of those most dangerous households have children. A half-million children — in Atlantic City, Philadelphia and Allentown, Pa., where a remarkable 23.1 percent of children tested had excessive lead — are believed to have enough lead in their blood to merit a doctor’s attention.

“We know that there are many kids across the country that have high lead levels in their bodies — testing kids identifies exposure that you can’t do anything about,” Jerome Paulson, an emeritus professor of public health and pediatrics at George Washington University and a longtime advocate for cleaning up the lead threat, tells me. The goal, he says, should be to “proactively identify the old housing and lead pipes and take care of them.”

“There will never be no kids in the U.S. with some adverse lead exposure, but we can certainly make it a much smaller problem than we have to date,” Paulson continues.

Successful national efforts have been made, such as the elimination of lead in gasoline, which was “extremely successful in reducing child lead exposure,” but “there’s never been a proactive federal approach to lead based paint poisoning or lead poisoning from the use of lead pipes for water,” Paulson says.

It wouldn’t be easy, to put it mildly, and Clinton’s proposal raises a host of questions. Among them would be how this commission would go about identifying the lead threat throughout the country and assembling all that knowledge in one place, Paulson says. Another would be how such policies would be implemented — Clinton stops short of proposing a legislative solution, though she doesn’t rule one out.

One possibility might be to incentivize states, communities, and localities to identify and tackle the problem, Paulson suggests. He adds that one model for this might be Madison, Wisconsin, which found elevated lead in its water in the 1990s and took proactive steps to eliminate all lead service lines.

A third problem would be that in many cases, the vehicles of lead-contamination — whether houses, buildings, or pipes — are either privately owned or partly owned by private owners while other parts are owned by municipalities. A fourth would be the ferocious resistance that such reforms would probably meet from other lawmakers. “I’m fairly certain that today’s Congress and many of today’s governors and legislators would not be in favor of such public health measures,” Paulson says.

David Rosner, a public health expert at Columbia University and the author of “Lead Wars,” says realizing this goal would be enormously ambitious, but ultimately worth the cost. “If we did this systematically by identifying the dilapidated housing and the children who are at risk, we could do it over a 30 or 40 year period,” Rosner says.

Clinton, meanwhile, has suggested accomplishing this in five years, which seems somewhat far fetched. Rosner notes, however, that the sheer ambition of the proposal — and Clinton’s explicit framing of the issue as a problem rooted in systemic racism — are themselves noteworthy.

“We have never been willing to address what is arguably the longest lasting childhood epidemic in American history,” Rosner says. “We’ve known about this from 1900 on. We know exactly what causes children to have lowered IQs and a whole host of other problems. And we’ve never been willing to deal with it because we’ve relegated it to a problem of poor people and people of color.”