Hillary Clinton’s proposal during Sunday night’s Democratic debate to remove the lead from “everywhere” in the country children might encounter it would be incredibly expensive—to the tune of well over $1 trillion. Fortune breaks down some of the costs here.
But she is right about an important point: pipes aren’t the country’s biggest problem. It's lead exposure levels overall. Lead exposure in the hardest hit areas of Flint, Michigan—where Sunday's night debate was held and the site of a major water contamination crisis—hovers around 6%. That’s unacceptably high—but, alarmingly, it’s lower than elsewhere in the nation, even in areas where pipes are relatively sound. In Detroit, where lead-tainted soil and paint are more common, 10.2% of children have higher than normal amounts of lead in their blood. In Allentown, Pa., that figure is 23.11%. Plus, Flint has the advantage of being on guard, where other communities are not.
The good news in the battle against lead in the U.S. is that it’s not as bad as it once was. The chart below shows the decline over the last two decades. The bad news is that it’s still a severe problem. Even after the country took steps to eliminate lead from gasoline and paint, the problem lingers, particularly in urban areas, where exposure tends to be significantly higher than average.
What comes next? Howard Mielke of the Department of Pharmacology at Tulane University School of Medicine has been studying the effect of lead on cities for years, says that action is urgent, and has been for a while. “We have evaluated lead in many cities and I suspect that each city has a festering lead exposure problem,” Mielke wrote Fortune in an email.
Mielke's solution: landscaping with low-lead soil in playgrounds and other areas. It would be, he says, a “less expensive and more effective” way of reducing exposure than any other tactic. “We have a clean air act, a clean water act, but no clean soil act,” he says. As an example, he points to Norway, which has a soil program to protect the kids who play in it.
But whether it’s soil, paint, or pipes—it will take significant political will to bring the nation’s lead exposure levels down to acceptable levels. As we saw in Sunday night's debate, Flint could very well serve as a rallying cry to start doing that.