Health Impact Assessment of Asian Dust/Cross-border Air Pollutant and Necessary Preventive Measure.

The health effects of Asian dust (mineral dust) originating from dry lands such as the Gobi Desert and Taklamakan Desert have recently been a concern. In addition to Asian dust, transboundary airborne microparticles that reach Japan include various types of aerosol, such as artificial air pollutants and smoke from combustion. They originate from densely populated areas and are transported along the same route as Asian dust. We analyzed environmental factors and subjective symptoms involving the respiratory organ, nose, eyes, and skin using a conventional equation for estimation, and found that symptoms with a significant risk of worsening varied according to the type of pollutants reaching Japan. We also analyzed the synergistic effects of Asian dust and pollens on nasal symptoms using a two-pollutant model. The odds ratio for symptoms at the time of arrival of a high concentration of Asian dust was 1.37 (95% confidence interval: 1.19-1.58), but the odds ratio adjusted for pollens was 1.18 (95% confidence interval: 1.04-1.34). Although the influence on nasal symptoms overlapped somewhat between Asian dust and pollens, that of Asian dust remained significant. Regarding preventive measures against symptoms, we examined the rate of particle leakage into masks. We found that it is important to wear a mask that fits an individual's facial features and has no gap between the face and the mask. In addition, we report our attempt to construct models for predicting aerosol arrival and forecasting health to establish preventive measures against aerosols.