title: Area-level socioeconomic deprivation, nitrogen dioxide exposure, and term birth weight in New York City.
abstract: Numerous studies have linked air pollution with adverse birth outcomes, but relatively few have examined differential associations across the socioeconomic gradient. To evaluate interaction effects of gestational nitrogen dioxide (NO2) and area-level socioeconomic deprivation on fetal growth, we used: (1) highly spatially-resolved air pollution data from the New York City Community Air Survey (NYCCAS); and (2) spatially-stratified principle component analysis of census variables previously associated with birth outcomes to define area-level deprivation. New York City (NYC) hospital birth records for years 2008-2010 were restricted to full-term, singleton births to non-smoking mothers (n=243,853). We used generalized additive mixed models to examine the potentially non-linear interaction of nitrogen dioxide (NO2) and deprivation categories on birth weight (and estimated linear associations, for comparison), adjusting for individual-level socio-demographic characteristics and sensitivity testing adjustment for co-pollutant exposures. Estimated NO2 exposures were highest, and most varying, among mothers residing in the most-affluent census tracts, and lowest among mothers residing in mid-range deprivation tracts. In non-linear models, we found an inverse association between NO2 and birth weight in the least-deprived and most-deprived areas (p-values<0.001 and 0.05, respectively) but no association in the mid-range of deprivation (p=0.8). Likewise, in linear models, a 10 ppb increase in NO2 was associated with a decrease in birth weight among mothers in the least-deprived and most-deprived areas of -16.2g (95% CI: -21.9 to -10.5) and -11.0 g (95% CI: -22.8 to 0.9), respectively, and a non-significant change in the mid-range areas [β=0.5 g (95% CI: -7.7 to 8.7)]. Linear slopes in the most- and least-deprived quartiles differed from the mid-range (reference group) (p-values<0.001 and 0.09, respectively). The complex patterning in air pollution exposure and deprivation in NYC, however, precludes simple interpretation of interactive effects on birth weight, and highlights the importance of considering differential distributions of air pollution concentrations, and potential differences in susceptibility, across deprivation levels.
authors: Department of Environmental and Occupational Health, University of Pittsburgh Graduate School of Public Health, Pittsburgh, PA, USA. Electronic address: jlcshmool@pitt.edu.
authors: Jessie L C
authors: JL
authors: Shmool
authors: Department of Biostatistics, Harvard School of Public Health, Boston, MA, USA.
authors: Jennifer F
authors: JF
authors: Bobb
authors: Bureau of Environmental Surveillance and Policy, New York City Department of Health and Mental Hygiene, New York City, NY, USA.
authors: Kazuhiko
authors: K
authors: Ito
authors: Department of Epidemiology, Brown University, Providence, RI, USA.
authors: Beth
authors: B
authors: Elston
authors: Department of Epidemiology, Brown University, Providence, RI, USA; Department of Obstetrics and Gynecology, Brown University, Providence, RI, USA.
authors: David A
authors: DA
authors: Savitz
authors: ZevRoss Spatial Analysis, Ithaca, NY, USA.
authors: Zev
authors: Z
authors: Ross
authors: Bureau of Environmental Surveillance and Policy, New York City Department of Health and Mental Hygiene, New York City, NY, USA.
authors: Thomas D
authors: TD
authors: Matte
authors: Bureau of Environmental Surveillance and Policy, New York City Department of Health and Mental Hygiene, New York City, NY, USA.
authors: Sarah
authors: S
authors: Johnson
authors: Department of Biostatistics, Harvard School of Public Health, Boston, MA, USA.
authors: Francesca
authors: F
authors: Dominici
authors: Department of Environmental and Occupational Health, University of Pittsburgh Graduate School of Public Health, Pittsburgh, PA, USA.
authors: Jane E
authors: JE
authors: Clougherty
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000633:toxicity*; D001724:Birth Weight; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D009519:New York City; D009585:Nitrogen Dioxide / Q000633:toxicity*; D012959:Socioeconomic Factors; D055815:Young Adult
chemical_list: D000393:Air Pollutants; D009585:Nitrogen Dioxide
keywords: Nitrogen dioxide; Socioeconomic deprivation; Term birth weight