Can the Social Safety Net Catch Lead? The Moderating Effect of WIC on Prenatal Lead Exposure

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Abstract

While decades of policy have successfully limited sources of lead, research shows that even low levels of exposure can have persistent, adverse health effects. Concern has largely been directed at children, but recent attention has shifted to prenatal exposure, in which a pregnant individual can pass inhaled lead through the placenta to the developing fetus. Quasi-experimental evidence has linked prenatal lead exposure, even at low levels, to a higher incidence of adverse birth outcomes such as low weight and pre-term births. The medical literature indicates that food security and nutrition, particularly calcium, play an important role in limiting lead absorption in the body. Disadvantaged populations, specifically low-income communities and communities of color, are disproportionately burdened by both lead exposure and food insecurity. Access to the social safety net is one avenue through which low-income individuals receive nutrition and care that might insulate them from the dangers of lead. I provide the first study to analyze social insurance channels as a moderating force against environmental hazards. To do this, I combine spatial variation in geographic access to the Special Supplementation Nutrition Program for Women, Infants, and Children (WIC) with spatial and temporal variation in lead exposure via the openings and closings of lead-releasing facilities documented in the Toxic Release Inventory. Using restricted birth certificate data from North Carolina, I categorize pregnant individuals by (1) exposure to an airborne lead shock and (2) geographic proximity to WIC clinics. I use a triple differences model to estimate the effect of shocks to prenatal lead exposure across residences geographically near and far from WIC clinics. I find that proximity to WIC offsets the adverse health effects of a positive lead shock during pregnancy, essentially insulating the birth from the harms of lead exposure. These results are largely driven by non-white individuals and individuals on Medicaid. Evidence that informs policymakers on how to best address lead exposure among these populations could have substantial welfare benefits, in addition to the possibly understated benefits of social safety net programs.

Author

• Alicia Marquez, Cornell University
  Presenting Author