Relationship between Air Pollution and Mortality Rate due to Chronic Obstructive Pulmonary Diseases in Mashhad, Iran

Air pollution causes respiratory diseases such as chronic obstructive pulmonary disease (COPD). In this study we aimed at statistical modeling of the effects of air pollution on mortality due to chronic pulmonary disease and COPD in Mashhad, Iran, using negative binomial regression. Mortality data due to chronic pulmonary diseases and the average amount of air pollutants per 24 hr were collected from 12 air pollution monitoring stations in Mashhad, 2011. Negative binomial regression was used as an appropriate statistical model to analyze discrete data. The effects of all pollutants, except PM particles and ozone particles, were found to have direct significant effect on mortality due to chronic pulmonary disease. The ratio of the incidence rate of mortality among patients with chronic pulmonary disease was highest for CO (IRR= 1.37, p<0.001), SO2 (IRR= 1.04, p<0.001), NO2 (IRR= 1.01, p<0.000), NO (IRR=1.003, p<0.000). But ozone had an inverse effect on chronic pulmonary mortality (IRR= 0.96, p<0.000). Among the pollutants, CO had the highest effect and O3 had a significant reverse effect on the rate of respiratory mortality. At the beginning of winter (January) we observed maximied rate of mortality and air pollution.