Association of Exposure to Fine Particulate Matter Constituents and Sources With Birth Weight

Abstract

PP-31-003 Background/Aims: Exposure to fine particles (particulate matter [PM2.5]) during pregnancy has been linked to lower birth weight; however, the chemical composition of PM2.5 varies widely. We investigated whether PM2.5 mass, constituents, and sources are associated with birth weight. Methods: PM2.5 filters were analyzed for over 50 elements for the period August 2000 to February 2004 for 3 counties in Connecticut and 1 in Massachusetts. Source apportionment techniques were used to estimate the daily contributions of PM2.5 associated with the sources of traffic, road dust/crustal, oil combustion, salt, and regional (sulfur). Gestational exposure to PM2.5 mass, constituents, and sources were examined in relation to birth weight and risk of low birth weight (<2500 g) for 76,788 infants. Results: Road dust and associated constituents, silicon and aluminum were associated with lower birth weight, as were the motor vehicle-related species such as elemental carbon and zinc, and the oil combustion-associated elements vanadium and nickel. An interquartile range increase in exposure was associated with low birth weight for zinc (12% increase in risk, 95% confidence interval [CI]: 3%–21%), elemental carbon (13%, 95% CI: 3%–24%), silicon (10%, 95% CI: 3%–13%), aluminum (11%, 95% CI: 3%–20%), vanadium (8%, 95% CI: 2%–15%), and nickel (11%, 95% CI: 3%–19%). Conclusion: Findings indicate that higher levels of certain chemical constituents of PM2.5 are associated with lower birth weight and increased risk of birth weight <2500 g. Evidence on the sources or constituents of particles that are most harmful is valuable to decision-makers in establishing public health policies.