Abstract
Correlation analysis between the incidences of chronic obstructive pulmonary diseases and various factors was performed using the data of the incidences, state of air pollution, and various socioeconomic factors. On simple correlation analysis, both the incidences of bronchial asthma and chronic bronchitis showed significant correlation with the density of the distribution of medical facilities and population density. A close association was observed also on partial correlation analysis between the incidence of bronchial asthma and the density of distribution of medical facilities. Multiple correlation analysis was performed by including and excluding the percentage of heavy smokers in socioeconomic factors to evaluate the effect of smoking on the incidences of bronchial asthma and chronic bronchitis, but no particular difference was confirmed in its contribution. The incidences of bronchial asthma, chronic bronchitis, and pulmonary emphysema were compared between a population of all ages and one aged 40 years or above separately in the contaminated area and a control area. The incidence of pulmonary emphysema was slightly higher, but those of bronchial asthma and chronic bronchitis were lower in the contaminated area than in other areas.
