Preliminary Research On The Relationships Between Meteorologic Factors And Resident Health In Nanjing

OBJECTIVE: In order to find out the trend of climate in Nanjing, research effects of meteorologic factors to mortality and incidence of chronic bronchitis, and establish a warning and forecasting model for terrible weather conditions.METHODS: The monthly changes of meteorologic factors and the trend of temperature change from 1951 to 2003 in Nanjing area were analyzed. Resident death conditions the last 10 years were studied. The effects of single meteorologic factor, especially temperature to total mortality, mortality by age and gender, mortality of the five leading causes and incidence of the chronic bronchitis were researched. Stepwise regression analysis was conducted, and the daily mortality of the five leading causes and incidence of the chronic bronchitis were fitted into the modeling as the dependent variable Y, and the meteorologic factors as the independent variables, which was promulgated in the form of health risk index.RESULTS: In the recently 50 years, the sharp warmer time of Nanjing was 1990s, and the temperature was going to heightening in 21 century. In summer, the daily highest temperature was up to 40℃, the relative humidity was higher than 80%, and the highest was more than 90%. In winter, the daily lowest temperature was low to -8℃, the relative humidity was higher than 70%. The mortality in winter was more than that in summer, and men more than women(t=5.65,P=0.0001). The summer mortalities in 1994, 1998 and 2003 were obviously higher than other years.In summer of Nanjing, the mortality increased with the temperature increasing, when the daily highest temperature was to a certain level, which in total mortality, older mortality, male and female mortality respectively was 35℃, 33℃, 35℃, 34℃, and according to disease type, respectively was 33℃, 35℃, 35℃, 34℃in respiration system disease, cerebrovascular disease, cardiavascular disease, injury and poisoning. In winter the critical temperatures in which the mortality increasing obviously respectively was 4℃, 4℃, 4℃, 2℃in total mortality, older mortality, male and female mortality, and according to disease type, it respectively was 1℃, 7℃, 6℃, in respiration system disease, cerebrovascular disease, injuryand poisoning. The result of poly ingredient analysis showed that the five leading mortality were affected by temperature, humidity, air pressure, wind speed, sunlight time and precipitation, especially the above factors of the last five days. The right rate of model forecast was up to 90%. The daily incidence of chronic bronchitis was observably related to differences in temperature with the previous day, and they were inverse ratio. The daily incidence was direct ratio with mean air pressure in autumn and winter. And the daily incidence was associated with wind speed in spring and summer.CONCLUSION: The climate continued to warm in 21 century. The mortality increased obviously when the daily highest temperature was up to 35℃and the daily lowest temperature was low to 4℃. The daily mortality was not only related to intraday weather conditions, but also the other day. Establishing the health risk indexes was helpful to reducing the mortality and facilitating resident health care. The steady weather conditions were not helpful to chronic bronchitis, but temperature descent and high air pressure were the inducements of it.