title: Effects of air pollution on postneonatal infant mortality among firstborn infants in Seoul, Korea: case-crossover and time-series analyses.
abstract: Infants are known to be susceptible to the adverse health effects of ambient air pollution. The authors examined the relationship between air pollution and postneonatal mortality from all causes among firstborn infants in Seoul, Korea, during 1999-2003, using both case-crossover and time-series analyses. Using a bidirectional control-sampling approach, the authors compared the effects of various types of air pollution on postneonatal mortality. The relative risk of postneonatal mortality from all causes was 1.000 (95% confidence interval [CI] = 0.998-1.002) for particulate matter with a diameter <10 mum, 1.002 (95% CI = 0.994-1.009) for nitrogen dioxide, 1.015 (95% CI = 0.973-1.058) for sulfur dioxide, 1.029 (95% CI = 0.833-1.271) for carbon monoxide, and 0.984 (95% CI = 0.977-0.992) for ozone for each 1-unit increase of air pollution level in the 1:6 control selection scheme. The authors observed a positive association between air pollution and infant daily mortality except for the studied particulate matter and ozone, although it was not statistically significant. They obtained similar results in the time-series analysis. The risk of postneonatal infant death from all causes was positively associated with all studied air pollutants except ozone. The authors also confirmed that the bidirectional method with many controls will give a more efficient estimator than will a method with fewer controls.
authors.affiliation: The Department of Public Health, Graduate School of Hanyang University, Seoul, Korea.
authors.forename: Ji-Young
authors.initials: JY
authors.lastname: Son
authors.forename: Yong-Sung
authors.initials: YS
authors.lastname: Cho
authors.forename: Jong-Tae
authors.initials: JT
authors.lastname: Lee
mesh_terms: D000397:Air Pollution / Q000009:adverse effects* / Q000032:analysis; D001722:Birth Order; D002248:Carbon Monoxide / Q000009:adverse effects / Q000032:analysis; D016022:Case-Control Studies; D015331:Cohort Studies; D018592:Cross-Over Studies; D006801:Humans; D007226:Infant Mortality; D007231:Infant, Newborn; D007723:Korea / Q000453:epidemiology; D009585:Nitrogen Dioxide / Q000009:adverse effects / Q000032:analysis; D052638:Particulate Matter / Q000009:adverse effects / Q000032:analysis; D012306:Risk; D013458:Sulfur Dioxide / Q000009:adverse effects / Q000032:analysis
chemical_list: D052638:Particulate Matter; D013458:Sulfur Dioxide; D002248:Carbon Monoxide; D009585:Nitrogen Dioxide