Decreased Lead Exposure is Associated with Improved Test Scores

Decreased Lead Exposure is Associated with Improved Test Scores
Anna Aizer, Janet Currie, Peter Simon, Patrick Vivier
National Bureau of Economic Research
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How are children’s standardized test scores connected with lead exposure? Researchers matched data from the Rhode Island Department of Health, the Rhode Island Department of Education, and birth certificates to create a longitudinal dataset for analysis. The dataset contained observations on approximately 71,000 children born in the state between January 1997 and September 2005, with at least one blood lead level measurement before age 6 and enrolled in a Rhode Island public school. The researchers compared standardized, third grade test scores and blood lead levels of children beginning with those born in 1997, the year Rhode Island implemented two measures to reduce lead in homes. The findings of this study “suggest that environmental regulations targeted at hazards that disproportionally impact minority children may have advantages beyond improvements in health.” Regulations that reduce lead exposure may help narrow the racial achievement gap.

Key findings:

  • The lead-safe certificate program, one of the two policy interventions in 1997, affected children in disadvantaged groups most significantly. For instance, the proportion of African American children living in a home certified as lead-safe when they were born increased from 2 percent in 1997 to 12 percent in 2005.
  • The policy interventions were linked to a 1.27 increase in mean reading scores among African American students and .88 among Hispanic students. These improvements in test scores decreased the Black-White test gap by one-third and the Hispanic-White test gap by one-fifth.
  • A decrease of one microgram of lead per deciliter of blood in average blood levels is associated with a reduced chance of scoring substantially below proficient in reading by 3.1 percentage points.