Wildfire and Infant Health at Birth: Evidence from New Jersey

Our study examines the impacts of prenatal exposure to wildfire on infant health at birth, specifically, the occurrences of low birth weight (LBW) and C-section procedure. Three main data sources are used in our analysis: birth records over the period 2004 to 2010 from New Jersey State Department of Health, information about all the significant wildfire events collected by New Jersey Office of Emergency Management and Federal Wildland Fire Occurrence Data, and air pollution data from Environmental Protection Agency (EPA). To identify prenatal exposure to any significant wildfire in each month of pregnancy, we use the detailed information on wildfires, mother’s residential information, newborn’s date of birth and gestational length. Newborns with mother’s residential address in the areas that were affected by any wildfire in any month during the pregnancy are defined as being exposed to wildfire in utero. And newborns with mother’s residential address in regions, which are adjacent to the affected areas but never affected by any wildfire, are defined as never exposed to any wildfire in utero. Our preliminary results indicate that prenatal exposure to any wildfire in the early stage of pregnancy is significantly impactful. Among the full-term births, being exposed to any wildfire in the first month of pregnancy would increase the probability of being low birth weight by 1.28 percentage points, and being exposed to any wildfire during the second and fourth month of pregnancy might increase the probability of having a C-section procedure by 3.57 and 4.32 percentage points respectively. Furthermore, we find that the impact on low birth weight is more likely to be present for females, and the impact on C-section procedures are present for both females and males. After controlling for air pollution caused by wildfire, we can still observe the adverse effect of prenatal exposure to wildfire. In this case, it suggests that maternal stress triggered by wildfire could be the channel, through which prenatal exposure to wildfire adversely affects infant health at birth.