Abstract
For the purpose of studying the influence of air pollution that causes pulmonary tuberculosis, the authors investigated the relationship between the level of pollution by area in Yokkaichi on the one hand, and prevalence, incidence, the visit rate to the physician and death rate of pulmonary tuberculosis on the other hand.
Prevalence and incidence showed a similar pattern and were influenced greatly by economic factors of the area as observed in the relationship with the on-relief rate, but the influence of air pollution was not found under the level of the pollution as shown in Table 1.
The visit rate to the physician taken by those insured by the National Health Insurance Plan was influenced more or less by social factors such as the density of medical institutions and density of population in addition to the above-mentioned economic factor, but had nothing to do with the air pollution.
Death due to pulmonary tuberculosis was caused by sulphur dioxide; when the mean concentration for three consecutive days surpassed 60ppb, the probability of the death on the last day became higher, the differrence being statistically significant at 5 per cent compared with days on which the concentrations were 19ppb or less.
