IYI Logo



Millions of tons of hazardous wastes have been produced in the United States in the last 60 years
which have been dispersed into the air, into water, and on and under the ground. Using new
population-level data that follows cohorts of children born in the state of Florida between 1994
and 2002, this paper examines the short and long-term effects of prenatal exposure to
environmental toxicants on children living within two miles of a Superfund site, toxic waste sites
identified by the Environmental Protection Agency as being particularly severe. We compare
siblings living within two miles from a Superfund site at birth where at least one sibling was
conceived before or during cleanup of the site, and the other(s) was conceived after the site
cleanup was completed using a family fixed effects model. Children conceived to mothers living
within 2 miles of a Superfund site before it was cleaned are 7.4 percentage points more likely to
repeat a grade, have 0.06 of a standard deviation lower test scores, and are 6.6 percentage points
more likely to be suspended from school than their siblings who were conceived after the site was
cleaned. Children conceived to mothers living within one mile of a Superfund site before it was
cleaned are 10 percentage points more likely to be diagnosed with a cognitive disability than their
later born siblings as well. These results tend to be larger and are more statistically significant
than the estimated effects of proximity to a Superfund site on birth outcomes. This study suggests
that the cleanup of severe toxic waste sites has significant positive effects on a variety of long-
term cognitive and developmental outcomes for children.


Source: National Bureau of Economic Research (2016). Inequality Before Birth: The Developmental Consequences of Environmental Toxicants.