2018 Volume 22 Issue 1-2 Pages 31-38
To evaluate the short-term effects of fine particulate matter（PM2.5）on respiratory health, epidemiological studies were conducted in two regions around the Seto Inland Sea in Japan. In Himeji City, Hyogo Prefecture, weekly data on asthma attacks reported from 46 hospitals and clinics and daily data on primary care visits（PCVs）due to asthma attacks were collected. The mass concentrations and chemical constituents of airborne PM2.5 were continuously measured at a central site in the city. The weekly numbers of asthma attacks were significantly associated with the average concentration of PM2.5 in the previous week among subjects aged 15 to 64 years. The concentration of water soluble organic carbon and acidity（hydrogen ions）were also significantly associated with weekly asthma attacks. These associations were marked in spring and summer. By contrast, the associations between daily PCVs for asthma and PM2.5 were significant in winter. On Yuge Island, Ehime Prefecture, peak expiratory flow（PEF）and the forced expiratory volume in 1 second（FEV1）were measured every morning among 48 healthy students, for about one month. Among subjects with a history of allergies, outdoor concentration of PM2.5 was significantly associated with a decrease in FEV1. The association between indoor concentration of PM2.5 and PEF was also significant. However, among subjects without such a history, neither outdoor nor indoor concentrations of PM2.5 were associated with changes in any parameters of pulmonary function. In conclusion, these studies revealed that increases of PM2.5 have short-term effects on respiratory health. Subjects with allergic diseases were considered to be more susceptible to air pollution.
