Non-Technical Summary:
Lead (Pb) pollution is a pervasive threat to childhood health and development since it is associated with substantial cognitive and behavioral impairments. Despite a dramatic decline in the prevalence of lead due to the prohibition of leaded gasoline, lead exposure is still widely recognized as a major public health issue primarily due to lead-based paint hazards in older housing. As is the case with other environmental threats, lead is heavily concentrated in disadvantaged communities and therefore contributes to the intergenerational transmission of inequality through its impact on early-life health.
Given the large body of evidence connecting childhood lead exposure to long-term outcomes, the U.S. Center for Disease Control (CDC) recommends blood lead testing for children around one and two years of age as well as a case management approach for children whose detected blood lead levels (BLLs) exceed an alert threshold. To reduce childhood exposure and mitigate long-term damage, public health officials implement a combination of actions to both remove lead in the environment through information and remediation as well as provide additional health and public assistance benefits for lead-poisoned children. Since the CDC lowered the alert threshold to 10 micrograms of lead per deciliter of blood in 1991, millions of children in the United States have been eligible for the early-life health and environmental treatments following test results showing elevated level of lead in the blood. Despite this large-scale public health response to lead-poisoned children, no previous studies have evaluated whether there are long-term behavioral or educational benefits associated with these environmental and health interventions.
We merge blood lead surveillance data, public school records, and criminal arrest records at the individual level to evaluate the long-term impact of these public health actions triggered by BLLs over the alert threshold on school performance and adolescent behavior in Charlotte, North Carolina. We identify the impact of intervention based on the fact that individuals with two consecutive tests over the alert threshold are eligible for intervention whereas individuals with an initial test over this threshold and a subsequent test just under the threshold are not. Consistent with a growing literature that finds profound impacts from early-childhood health interventions on long-term cognitive and behavioral outcomes, we find that interventions triggered by elevated blood lead levels significantly reduce adolescent antisocial behavior and increase academic achievement. The magnitudes of our estimates suggest that the behavioral and educational impairments previously associated with early-life lead exposure can largely be reversed by the intervention.