American Journal of Epidemiology Advance Access originally published online on April 24, 2009
American Journal of Epidemiology 2009 169(11):1327-1336; doi:10.1093/aje/kwp067
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ORIGINAL CONTRIBUTIONS |
Association of Early-life Exposure to Household Gas Appliances and Indoor Nitrogen Dioxide With Cognition and Attention Behavior in Preschoolers
Correspondence to Dr. Jordi Sunyer, Center for Research in Environmental Epidemiology, Parc de Recerca Biomèdica de Barcelona, C / Dr. Aiguader 88, Barcelona E-08003, Catalonia, Spain (e-mail: jsunyer{at}creal.cat).
Received for publication September 25, 2008. Accepted for publication February 27, 2009.
The authors investigated the association of early-life exposure to indoor air pollution with neuropsychological development in preschoolers and assessed whether this association differs by glutathione-S-transferase gene (GSTP1) polymorphisms. A prospective, population-based birth cohort was set up in Menorca, Spain, in 1997–1999 (n = 482). Children were assessed for cognitive functioning (McCarthy Scales of Children's Abilities) and attention-hyperactivity behaviors (Diagnostic and Statistical Manual of Mental Disorders, 4th Edition) at age 4 years. During the first 3 months of life, information about gas appliances at home and indoor nitrogen dioxide concentration was collected at each participant's home (n = 398, 83%). Genotyping was conducted for the GSTP1 coding variant Ile105Val. Use of gas appliances was inversely associated with cognitive outcomes (β coefficient for general cognition = –5.10, 95% confidence interval (CI): –9.92, –0.28; odds ratio for inattention symptoms = 3.59, 95% CI: 1.14, 11.33), independent of social class and other confounders. Nitrogen dioxide concentrations were associated with cognitive function (a decrease of 0.27 point per 1 ppb, 95% CI: –0.48, –0.07) and inattention symptoms (odds ratio = 1.06, 95% CI: 1.01, 1.12). The deleterious effect of indoor pollution from gas appliances on neuropsychological outcomes was stronger in children with the GSTP1 Val-105 allele. Early-life exposure to air pollution from indoor gas appliances may be negatively associated with neuropsychological development through the first 4 years of life, particularly among genetically susceptible children.
air pollution, indoor; attention deficit disorder with hyperactivity; child development; cognition; fossil fuels; glutathione transferase; nitrogen dioxide; polymorphism, genetic
Abbreviations: ADHD, attention deficit hyperactivity disorder; GSTP1, glutathione S-transferase P1