Early Lead Exposure and its Effects on Academic Achievement and Earnings : Evidence from an Environmental Negligence

Abstract

Between 1984 and 1989 more than 20,000 tons of toxic chemicals containing high concentrations of lead were brought to the city of Arica (in northern Chile). Initially, the chemical waste was located several kilometers from the city. The rapid expansion of Arica in the early 1990s, which included the construction of social housing projects meters away from the waste deposit, put a large number of families at risk. For more than a decade, individuals living in the vicinity of the contaminated areas were exposed to critical levels of lead. The medical literature suggests that even minimum lead exposure might have long-term effects on individual's behavior and cognitive ability. However, there is little evidence showing direct effects on academic achievement and (fortunately) the literature rarely examines cases in which large numbers of individuals have been affected by lead exposure. In this paper we examine the effects of lead exposure on academic achievement in the case of Arica. We analyze longitudinal data from a large population of individuals living and attending primary and secondary schools in Arica between 2004 and 2008. Our data include longitudinal information on proximity to the polluted areas (from individual's place of residence), levels of lead exposure, comprehensive sets of controls, and multiple nationally representative academic test scores. Our findings indicate significant and negative effects of household proximity to contaminated areas on student academic performance. We also estimate the effect of blood lead levels on student academic performance, finding significantly negative effects. Finally, combining these estimates with those obtained from regressions of annual earnings on student's academic performance, we provide an estimate of the effect of lead exposure on life-time earnings.