Panel Paper: The Effect of an Increase in Lead in the Water System on Fertility, Pregnancy, and Birth Outcomes: The Case of Flint, Michigan

Saturday, November 4, 2017
Stetson BC (Hyatt Regency Chicago)

*Names in bold indicate Presenter

Daniel S Grossman, West Virginia University and David Slusky, University of Kansas

There is overwhelming evidence that lead in water contributes to higher rates of lead in the blood, and is related to eventual developmental problems in children. However, testing for lead in infants is not routinely performed, despite the fact that a separate large literature underscores the importance of in utero health on long-term health and human capital development. Lead likely passes through the placenta to the fetus beginning in the second trimester of pregnancy (see e.g. Amaral et al. 2010). Maternal exposure to lead is correlated with prenatal growth abnormalities, reduced gestational period, and reduced birth weight (Zhu et al. 2010; Taylor, Golding, & Emond 2014).

Flint, Michigan changed the source of its publicly provided water in April 2014, causing an increase in the levels of lead in water delivered to its citizens. The effect of high levels of lead in water on fertility and birth outcomes is not well established. Our overall objective in this application is to determine the health effects of an exogenous change in the amount of lead in the water supply on the health of pregnant women and their babies. We utilize a natural experiment in the exposure caused by an exogenous change in the water supply: namely that Flint, Michigan, changed the source of its publicly provided water in April 2014, while areas directly surrounding Flint did not change their water source.

We use detailed geocoded data containing the universe of births in Michigan from 2008 to 2015. Exploiting variation in the timing of births, we find overall general fertility rates decrease by 10% in Flint following the water change. We also find a decrease in health among births. These results suggest both a culling of the least healthy fetuses and a shift in the health distribution in Flint due to scarring. This research provides a timely analysis of the effect of the Flint water crisis and contributes to the fetal origin literature and studies focusing on the effect of pollutants on health and development.