Wildfires and Infant Health

PROJECT SUMMARY
Climate change is increasing the frequency and intensity of wildfires in the United States. By 2011, 25-40% of
all small particulate matter air pollution in the US was attributed to wildfires and the contribution of wildfires to
air quality will likely increase as they proliferate and other anthropogenic sources decline. Wildfire produced air
pollutants are spread across thousands of miles by prevailing winds. Wildfires, and the air pollutants carried by
their smoke plumes, have profound impacts on adult health. However, far less is known about their impacts on
infants, who are particularly sensitive to the adverse exposures associated with wildfire events. Air pollution,
psychosocial stress, and community disruption in the prenatal period and in the first year of life could adversely
impact birthweight, gestational age, hospital service use, and infant mortality. The proposed project will link
high-resolution, state-of-the-art exposure measures, developed from satellite observations, ground monitors,
and numeric modeling with natality, hospital discharge, and mortality records from 2003-2019. Natality and
linked birth-death records cover a near census of births from every US county. Hospital discharge records,
from 15 states, include all discharges from all payers, and have been individually linked to birth and death
records. The three specific aims are to: (1) Measure the extent and sociodemographic, geographic, and
temporal patterns of prenatal and first year of life exposure to smoke-plumes, wildfire produced air pollutants,
and local wildfire events; (2) Estimate the impact of total pregnancy and trimester specific wildfire exposure on
health at birth, health service use, neonatal and infant mortality; and (3) Examine the moderating influence of
socio-demographics and baseline air pollutant exposures. The impact of wildfire exposures on infant health will
be estimated in a fixed effects regression framework that isolates the impact of exposure from confounders
that predispose infants with different health risks to wildfire exposure. Our approach compares wildfire-exposed
infants to wildfire-unexposed infants born in different years, but in the same county and calendar month. Our
analytic framework provides a direct method for testing for the presence of pre-existing trends, a principal
threat to causal inference. Results from our study will be the first national estimates of infant exposure to
wildfires and smoke-plumes, and their impacts on infant health outcomes. Our findings will be critical for
mitigation planning as climate change continues to accelerate wildfire growth in the coming decades.

Grant Number: 5R01ES033963-04
NIH Institute/Center: NIH
Principal Investigator: Michel Boudreaux