Acute myocardial infarction and COPD attributed to ambient SO2 in Iran

Acute myocardial infarction (MI) and chronic obstructive pulmonary disease (COPD) are important diseases worldwide. Inhalation is the major route of short-term exposure to air sulfur dioxide (SO2) that negatively affect human health. The objective of this study was to estimate the health effects of short-term exposure to SO2 in Khorramabad, Iran using the AirQ software developed by the World Health Organization (WHO). Daily mean SO2 concentrations were used as the estimates of human short-term exposure and allow calculation of the attributable excess relative risk of an acute MI and hospital admissions due to COPD (HACOPD). The annual mean SO2 concentration in Khorramabad was 51.33 µg/m3. Based on the relative risk (RR) and baseline incidence (BI) approach of WHO, an increased risk of 2.7% (95% CI: 1.1-4.2%) of acute MI and 2.0% (95% CI: 0-4.6%) of HACOPD, respectively, were attributed to a 10 µg/m3 SO2 increase. Since the geographic, demographic, and climatic characteristics are different from the areas in which the risk relationships were developed and not evaluated here, further investigations will be needed to fully quantify other health impacts of SO2. A decreased risk for MIs and COPD attributable to SO2 could be achieved if mitigation strategies and measures are implemented to reduce the exposure.