Air pollution and individual and neighborhood socioeconomic status: evidence from the Multi-Ethnic Study of Atherosclerosis (MESA).
BACKGROUND
Although research has shown that low socioeconomic status (SES) and minority communities have higher exposure to air pollution, few studies have simultaneously investigated the associations of individual and neighborhood SES with pollutants across multiple sites.


OBJECTIVE
We characterized the distribution of ambient air pollution by both individual and neighborhood SES using spatial regression methods.


METHODS
The study population comprised 6,140 participants from the Multi-Ethnic Study of Atherosclerosis (MESA). Year 2000 annual average ambient PM2.5 and NOx concentrations were calculated for each study participant's home address at baseline examination. We investigated individual and neighborhood (2000 U.S. Census tract level) SES measures corresponding to the domains of income, wealth, education, and occupation. We used a spatial intrinsic conditional autoregressive model for multivariable analysis and examined pooled and metropolitan area-specific models.


RESULTS
A 1-unit increase in the z-score for family income was associated with 0.03-μg/m3 lower PM2.5 (95% CI: -0.05, -0.01) and 0.93% lower NOx (95% CI: -1.33, -0.53) after adjustment for covariates. A 1-SD-unit increase in the neighborhood's percentage of persons with at least a high school degree was associated with 0.47-μg/m3 lower mean PM2.5 (95% CI: -0.55, -0.40) and 9.61% lower NOx (95% CI: -10.85, -8.37). Metropolitan area-specific results exhibited considerable heterogeneity. For example, in New York, high-SES neighborhoods were associated with higher concentrations of pollution.


CONCLUSIONS
We found statistically significant associations of SES measures with predicted air pollutant concentrations, demonstrating the importance of accounting for neighborhood- and individual-level SES in air pollution health effects research.
Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA.
Anjum
A
Hajat
Ana V
AV
Diez-Roux
Sara D
SD
Adar
Amy H
AH
Auchincloss
Gina S
GS
Lovasi
Marie S
MS
O'Neill
Lianne
L
Sheppard
Joel D
JD
Kaufman
D000368:Aged; D000369:Aged, 80 and over; D000393:Air Pollutants / Q000032:analysis*; D050197:Atherosclerosis / Q000453:epidemiology*; D015331:Cohort Studies; D004781:Environmental Exposure / Q000706:statistics & numerical data*; D004782:Environmental Health / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D012923:Social Class; D014481:United States / Q000453:epidemiology
D000393:Air Pollutants