[The weather chart pattern inducing asthma attack: the advocacy of "fine mist" as a provocative factor]

Outbreaks of asthma attack on 345 patients were studied in relation to the atmospheric phenomena. About 76% of days in which multiple attacks took place were fit with either of the following atmospheric conditions, 1) the trough of atmospheric pressure, 2) the approach of Typhoon, 3) the cold advection, in Japan. The common feature of these different atmospheric conditions are the tendency to turn excess vapor into fine water particles (fine mist). The fine mist could stimulate irritable airway to asthma attacks ("fine mist" hypothesis). To verity this hypothesis each asthmatic attack was further studied. It fitted in 70.7% of the attacks (fitting group) and not in 29.3% of the attacks (non-fitting group). Frequency of asthmatic attacks varied in every month on fitting group, but was nearly constant on non-fitting group. The average of the daily change of vapor density was calculated monthly. And it appeared that its graphic pattern was similar to the graphic pattern of asthmatic attack frequency. Thus it is supposed that there are at least two factors that could induce asthmatic attacks, one would be fine mist, others are unknown.