The Relationship between Air Pollution and Emergency Room Visits in an Industrial Community

Abstract

This study assessed the relationship between air pollution levels and numbers of emergency room visits in an industrial town. Records of emergency room visits to the major hospital during March, April, October, and November of 1974–1977 were abstracted. Air pollution and temperature data were collected from instruments located centrally, near the hospital. For the analyses, the morbidity indices were the deviations of daily visit numbers from the expected values based on day of week, season, and year. The diagnostic categories were collapsed to “all respiratory diseases,” “all diseases but trauma,” and “all diseases.” The mean deviations for each category were first grouped by pollutant quartile and by maximum temperature. These deviations did not vary in a fashion consistent with a pollutant effect for SO₂, TSP, NO₂, CO, or O₃—either unlagged or lagged by 24 hours. A linear regression model showed small but statistically significant effects of unlagged TSP and of unlagged SO₂ on the respiratory disease index. For TSP, however, days above the 24-hr federal standard were not associated with excess respiratory disease visits. These analyses demonstrate at most a limited association between air pollutant visits and respiratory disease emergency room visits.