Air pollution, socioeconomic position, and emergency hospital visits for asthma in Seoul, Korea

Sun Young Kim, Marie S. O'Neill, Jong Tae Lee, Youngtae Cho, Jaiyong Kim, Ho Kim

Research output: Contribution to journalArticlepeer-review

41 Citations (Scopus)


Objective: Some epidemiological literature has observed that air pollution effects on health differed across regional or individual socioeconomic position. This study evaluated whether regional and individual socioeconomic position, as indicated by health insurance premiums, modified the effect of air pollution on hospital visits for asthma. Methods: Effects of ambient air pollutants (particulate matter,carbon monoxide, sulfur dioxide, nitrogen dioxide, and ozone) on 92,535 emergency out-patient hospital visits for asthma in Seoul, Korea during 2002 were estimated using case-crossover analysis, adjusting for time trend, weather conditions, and seasonality. Next, interactions between air pollutants and Korean National Health Insurance premium (1) for the individual patient and (2) averaged across the patient's residence district, were entered, first singly then jointly, in the models. Results: Relative risks of emergency outpatient hospital visits were all positively and significantly associated with interquartile increases for selected lags for all air pollutants. In the regression model with interaction terms for both individual premium and regional-average premium, associations with all five-air pollutants ranged from 1.03 to 1.09 times higher among the lowest premium districts compared to the highest premium districts. Of all the pollutants, nitrogen dioxide showed the strongest associations in lower premium districts compared to the higher premium districts. Individual socioeconomic position did not modify the associations in either the single or joint interaction models. Conclusion: In Seoul, community but not individual socioeconomic conditions modified risk of asthma hospital visits on high air pollution days.

Original languageEnglish
Pages (from-to)701-710
Number of pages10
JournalInternational Archives of Occupational and Environmental Health
Issue number8
Publication statusPublished - 2007 Aug
Externally publishedYes

Bibliographical note

Funding Information:
Acknowledgments This study was supported by the grant from the Basic Research Program of Korea Science and Engineering Founda- tion (no. R01-2002-000-00554-0), the Korean Research Foundation Grant funded by the Korean Government (KRF-2005-214-E00041), and the Robert Wood Johnson Health and Society Scholars Program.


  • Air pollution
  • Asthma
  • Effect modifier
  • Residence characteristics
  • Socioeconomic factors

ASJC Scopus subject areas

  • Public Health, Environmental and Occupational Health


Dive into the research topics of 'Air pollution, socioeconomic position, and emergency hospital visits for asthma in Seoul, Korea'. Together they form a unique fingerprint.

Cite this