Objective To investigate the effect of the main atmospheric pollutants on the mortality of malignant tumor in Suzhou City.
Methods The daily death cases due to malignant tumor and daily average air concentration of inhaled particulate matter(PM10), sulfur dioxide(SO2), nitrogen dioxide(NO2) and carbon monoxide(CO) were collected; then the relationship between them was analyzed with methods of time series and multiple linear regression.
Results (1) There were significant correlations between the daily mortality of malignant tumor and the daily mean concentrations of air pollutants (for example, SO2 (lag7) and PM10 (lag0), P < 0.05) in this city. The estimated relative risk (RR) and 95% interval confidence(95% CI) of the mortality of malignant tumor for each 10 μg/m3 elevation of SO2 and PM10 were 1.004 (1.003-1.006, P < 0.01)and 1.001 (1.000-1.002, P < 0.05)respectively; and the raise ratio of the daily mortality of malignant tumor for SO2 and PM10 were 0.44% (0.29%-0.60%) and 0.10% (0.01%-0.19%); while there was negative correlation for NO2(P < 0.01).(2) There were obvious multiple linear regression between the mortality and the concentration of pollutants(P < 0.05). The regression equation was & #375;=4.985+ 3.963SO2-2.878NO2+0.577PM10. The predicted result was coincident with the actual number. (3)Based on the result of the standardized coefficients, the maximum influence was the independent variable of SO2 on the dependent variable of the mortality of malignant tumor.
Conclusion In this city, there was significantly positive correlation and linear regression between the mortality of malignant tumor and the concentration of air pollutants (SO2 and PM10, but not NO2). The key point about the decrease of the mortality of malignant tumor was to control the pollution level of SO2.
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