title: Socioeconomic status and exposure to outdoor NO2 and benzene in the Asturias INMA birth cohort, Spain.
abstract: BACKGROUND
  It is commonly assumed that low socioeconomic levels are associated with greater exposure to pollution, but this is not necessarily valid. Our goal was to examine how individual socioeconomic characteristics are associated with exposure levels in a Spanish region included in the INfancia y Medio Ambiente (INMA) cohort.
  
  
  METHODS
  The study population comprised 430 pregnant women from the Asturias INMA cohort. Air pollution exposure was estimated using land-use regression techniques. Information about the participants' lifestyle and socioeconomic variables was collected through questionnaires. In multivariate analysis, the levels of NO2 and benzene assigned to each woman were considered as dependent variables. Other variables included in the models were residential zone, age, education, parity, smoking, season, working status during pregnancy and social class.
  
  
  RESULTS
  The average NO2 level was 23.60 (SD=6.50) μg/m(3). For benzene, the mean value was 2.31 (SD=1.32) μg/m(3). We found no association of any pollutant with education. We observed an association between social class and benzene levels. Social classes I and II had the highest levels. The analysed socioeconomic and lifestyle variables accounted for little variability in air pollution in the models; this variability was explained mainly by residential zone (adjusted R(2): 0.27 for NO2; 0.09 for benzene).
  
  
  CONCLUSIONS
  Education and social class were not clearly associated with pollution. Administrations should monitor the environment of residential areas regardless of the socioeconomic level, and they should increase the distances between housing and polluting sources to prevent settlements at distances that are harmful to health.
authors.affiliation: Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Instituto de Salud Carlos III, , Madrid, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Fernández-Somoano
authors.forename: Adonina
authors.initials: A
authors.lastname: Tardon
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000032:analysis*; D001554:Benzene / Q000032:analysis; D015331:Cohort Studies; D004784:Environmental Monitoring / Q000379:methods / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D016014:Linear Models; D018811:Maternal Exposure / Q000706:statistics & numerical data*; D015337:Multicenter Studies as Topic; D009585:Nitrogen Dioxide / Q000032:analysis; D052638:Particulate Matter / Q000032:analysis; D011247:Pregnancy; D012923:Social Class; D013030:Spain; D001335:Vehicle Emissions / Q000032:analysis; D055815:Young Adult
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D001335:Vehicle Emissions; D001554:Benzene; D009585:Nitrogen Dioxide
keywords: Air Pollution; Environmental epidemiology; Occupational Health