Maternal Health and Pregnancy Exposure to Lead: A Case Study of Flint, Michigan.

The water contamination resulting from switching of water source in Flint, Michigan, exposed all the residents of the city to biological and chemical contaminants, including lead. This paper studies the impact of the water switch on maternal health following exposure during pregnancy. Using Michigan birth records for 2013-2015, we compare births in Flint after the water switch to those in other cities across the state. Our findings show evidence of maternal selection, as mothers are less educated and less likely to be enrolled in Medicaid. We also estimate a change in pre-natal maternal health: a 0.7 percentage point increase in diabetes, and significant declines in incidence of infections. However, after the water switch mothers in Flint are 4.8 percentage point more likely to be smokers, and 20 percentage points less likely to quit smoking during pregnancy. We attribute this reluctance to quit smoking to increased stress resulting from uncertainty and anxiety surrounding water quality in the community. We find some evidence of avoidance behaviour, with on average 0.45 more prenatal visits, and a 2.0 percentage point decline in incidence of gestational hypertension in this population. Our findings show that stress and avoidance behaviour play an important role in population response to exposure to contamination in Flint. Though focus remains on the impact of exposure to actual contaminant, we show that the stress and behavioural response may have a greater and more detrimental impact on individual well-being.