Effects of air pollution on postneonatal infant mortality among firstborn infants in seoul, Korea: Case-crossover and time-series analyses

Ji Young Son, Yong Sung Cho, Jong Tae Lee

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14 Citations (Scopus)


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 μm, 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.

Original languageEnglish
Pages (from-to)108-113
Number of pages6
JournalArchives of Environmental and Occupational Health
Issue number3
Publication statusPublished - 2008 Jan 1



  • Air pollution
  • Case-crossover design
  • Firstborn infants
  • Postneonatal infant mortality
  • Time-series analysis

ASJC Scopus subject areas

  • Toxicology
  • Environmental Science(all)
  • Public Health, Environmental and Occupational Health
  • Health, Toxicology and Mutagenesis

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