Decrease in Sulfur Oxides Air Pollution and Resulting Effects on Health in Yokkaichi Area

开展了各种类型的流行病学调查，以评估改善横海道地区硫氧化物空气污染的效果。医保收据就诊率及新发病人发生率调查：通过调查医保缴费明细表，调查慢性阻塞性呼吸系统疾病就诊率及新发病人发生率。污染地区的就诊率是目前对照地区的两倍多--在二氧化硫环境标准达到10多年后。另一方面，在污染区，直到1980年各年龄段的哮喘和40岁以上的慢性支气管炎患者的新发病例的发病率均呈较高的水平，而此后发病率已下降到对照…的水平。由于环境污染的改善，对这两种疾病都有更多的EA。呼吸道症状患病率：自1963年起简化BMRC调查表，并向污染区所有40岁以上居民发放问卷，调查慢性支气管炎和哮喘发作的患病率，这两种症状在污染程度较高的行政区域患病率较高。在达到二氧化硫的环境标准之前，所有地区的慢性支气管炎患病率都在上升，此后由于污染的改善，发病率有所下降。目前，除污染最严重的两个地区外，其他地区的降幅均低于对照地区。哮喘发作的患病率对污染的改善表现出高度的敏感性，除1个地区外，其余地区均已提高到对照地区水平。慢性阻塞性呼吸系统疾病的死亡率：自1963年以来，对慢性阻塞性呼吸系统疾病的死亡率进行了20多年的调查。在污染区域。在二氧化硫环境达标后4-5年提高到参照区水平。较少

Various types of epidemiological investigation have been performed to evaluate the effect of the improvement of air pollution by sulphur oxides in Yokkaichi area.1. Survey of the visit rate to physician and the incidence of the new patients using the receipts of National Health Insurance: By investigating the payment statement for national health insurance, the visit rate to physician and the incidence of the new patients for chronic obstructive respiratory diseases were surveyed. Visit rate to physician in the pollution area was more than twice as high as that of the control area at present - more than 10 years after the environmental standards for sulphur dioxide were met. On the other hand, the incidence of the new patients had been found at higher rate in the pollution area until 1980 for bronchial asthma in all age groups and until 1979 for chronic bronchitis for the patients of 40 years old of older, whereas the incidence has been reduced thereafter to the level of the control ar … More ea for both of these diseases because of the improvement in the environmental pollution.2. Prevalence of respiratory symptoms: The surveyb slip of B.M.R.C. was simplified from 1963, and the questionnaire was disseminated to all residents older than 40 years old in the polluted area to investigate the prevalence of chronic bronchitis and asthmatic attacks both of these symptoms showed higher prevalence in the administrative area with higher pollution. The prevalence of chronic bronchitis increased for all areas until environmental standards for sulphur dioxide were met, and it was decreased thereafter due to the improvement of pollution. At present, it was decreased as low as that of the control area except two areas, where the pollution was at the severest. The prevalence of asthmatic attacks responded with high sensitivity to the impovement of the pollution, and it was improved to the level of the control area except one area.3. Mortality from chronic obstructive respiratory diseases: The mortality from chronic obstructive respiratory diseases has been investigated for more than 20 years since 1963. In the pollution area. it was improved to the level of the reference area 4-5 years after the environmental standards for sulphur dioxide were satisfied. Less