[Air pollution (NO2, suspended particulate material) and the number of acute hospitalization of patients with asthmatic attack].

There were many reports about the relationship between the air pollution and the incidence of asthma. In Japan some of the concentrations of air pollutants, for example, SO2, CO, have been reduced in these ten-twenty years. However the concentrations of suspended particulate material (SPM) and NO2 have not been reduced, and the incidence of bronchial asthma have been increasing gradually. The relationship between the concentrations of NO2, SPM and the number of patients admitted to our hospital because of asthmatic attack was studied. The concentration of each air pollutant was measured at the air quality monitoring stations in Minami-ku and Jonan-ku Fukuoka, Japan. Between Jan, 1988 and Dec. 1991, 3661 patients with asthmatic attacks were admitted to our hospital. The relationship between the monthly averaged one-hour mean value for a day, and monthly max. of one-hour mean. value for a day, and one-day max. value for a month of NO2 and SPM and the numbers of asthmatic attack patients admitted was evaluated. There was a statistically significant relationship between concentrations of NO2 and SPM levels and the numbers of asthmatic patients admitted aged 6 or less. However, there was no such a relationship when the patients were aged between 7 and 20. These results suggested that the airways of asthmatic patients in the age of 6 or less might be more sensitive to NO2 and SPM than that of those patients in the age of 7 to 20.