Until the late 1990s, lead-based paint was a ubiquitous feature of Rhode Island's lowest-income rental properties. After the state passed legislation requiring landlords to remove the paint, public health experts predicted that the high blood levels of lead found in resident children would begin to decline.

But according to Anna Aizer, Associate Professor of Economics, children's lead levels were in decline even before the law went into effect. The culprit? Yet another environmental source of the same chemical: leaded gasoline, which had been phased out of circulation incrementally over the preceding 20 years.

Such declines are good news for younger generations; however, for those born before environmental sources of lead were addressed, the health effects are very real indeed. Like many heavy metals, lead is highly neurotoxic—especially in children. High lead levels in childhood have been linked to a variety of cognitive health problems throughout the lifespan. Moreover, the burden of lead often falls on the most disadvantaged children, perpetuating their social and economic limitations.

Aizer sees these types of environmental health questions as fundamentally economic issues. "Economists spend a lot of time trying to understand the determinants of what we refer to as human capital," she explains. "Human capital is everything that makes you productive, and those can be both cognitive and non-cognitive skills. And to the extent to which the environment influences people's development of human capital—that makes it an economic problem."

Aizer is currently working on two projects: one that explores the effect of childhood lead exposure on test scores, and another that seeks to determine whether such exposure predicts future disciplinary infractions and crime. There is a wide base of literature around these two topics; but Aizer's work is especially strong, due in part to Rhode Island's uniquely comprehensive lead screening campaign.

"Nationally, maybe 25% of kids ever get screened for lead, and in Rhode Island that number is closer to 80%," she says. "We are actually getting kind of a universe of kids, so we have a really good picture of the lead burden in Rhode Island—moreso than you do in most states."

Aizer's results confirm the adverse effects of early lead exposure on children's brains, especially for those who are below the curve academically. "For the average kid, it's not mattering a whole lot," she explains. "But for kids who are at the bottom of the test score distribution, lead levels are very predictive of how well they do."

She and her team have also found that lead levels are, indeed, predictive of disciplinary infractions in school and juvenile detention later in life.

Aizer is hopeful that her work will help to inform future policy decisions. "I think [this research] really does support the notion that we should be spending money reducing children's exposure to lead, particularly disadvantaged children," she says.

In this respect, Rhode Island could serve as an example for other areas. The state has done a particularly good job of addressing the issue of lead paint in rental homes, she explains—and at a cost that is not astronomical to landlords.

In Aizer's view, removing lead from children's environments is a moral imperative; however, it is also an economically smart decision: "I think targeted efforts to reduce exposure to lead among these groups will have long-term gains, and that these remediation programs are likely to be very much cost-effective."