Lead poisoning has long been linked to lower IQs, behavioral problems and other disabilities — but more recently, scientists have used to it explain patterns of violent crime in the United States and around the world.
While the past 50 years have seen vast improvements in lead regulation, the side effects of exposure are grave and still present.
Two very important environmental regulations, the Clean Air Act and the Lead-Based Paint Poisoning Prevention Act, were implemented in the 1970s and 1980s. These paved the way for a total ban on leaded gasoline in the 1990s and contributed to what many consider one of the biggest public health successes in the past quarter century.
Removing lead from automotive fuel, paint, toys and water was accompanied by an 80 percent reduction in blood lead levels between 1976 and 1999, according to Harvard and CDC researchers.
Prior to the 1970s, when gasoline still contained lead, car exhaust would spew it into air, from which it would ultimately settle into the dirt and water. The ubiquitous nature of these two substances has contributed to lead’s continued effects, despite removal efforts.
Additionally, aging city infrastructures, such as plumbing, sewage and water supplies, pose no small threat. The Flint water crisis is a perfect example of this. Old service lines to homes, in addition to improperly treated water, doubled the percentage of children with elevated blood lead levels from 2013 to 2015.
Cities such as Cleveland, Ohio, with neighborhoods full of old homes covered in lead-ridden paint, also pose a huge threat to their residents. Of children tested in Cleveland, 14.2 percent had elevated levels of lead in their blood.
Though the visualization above does not account for homes that may have been renovated, it directionally represents which U.S. areas may have the most houses that pose lead-related health risks. According to the Environmental Protection Agency, there is “no demonstrated safe concentration of lead in blood.” Even levels under 10 ug/dL, which was once believed to be safe, can reduce IQ by up to seven points.
Not only does the government have an inherent responsibility to control the exposure of its citizens to lead for health reasons, it also has a long-term financial incentive. One study estimated that every dollar spent on lead hazard control could yield a net return of 17 to 221 dollars by saving money on special education, crime control and increasing tax revenue by having more healthy, working members of society.
When President Obama declared a state of emergency in Michigan due to the lead in Flint’s water, the federal aid sent their way was a step in the right direction — but given the long-standing knowledge of lead’s effects, it’s easy to wonder why resources weren’t allocated to prevent this disaster in the first place. The country has made great strides in limiting lead exposure since the 1970s, but it’s clear that the fight is not over.