The Effects Of Air Pollutants On Lung Cancer And COPD Mortality In A Retrospective Cohort Study

Objective: With the rapid development of economic globalization,ambient air pollution is becoming more and more serious,bringing numbers of challenges to the sustainable development of our country and society.What's more,most cohort studies that assess long-term exposure to air pollution and disease mortality mainly comes from the United States or European countries,where compared with the developing countries,the annual concentrations of ambient air pollution are relatively lower.Thus,our study was established to investigate the relationship between long-term exposure to particulate matter less than 10 micrometers in diameter(PM10),sulfur dioxide(SO2)and the mortality of lung cancer and chronic obstructive pulmonary disease(COPD)in Northern China.Another aim of our study was to explore the effect modification of the covariates by performing stratified analyses.Methods: 1.We sorted monitoring data from all environmental monitoring sites in the four cities,and calculated the annual average concentrations for PM10 and SO2 based on the 24-hour average concentrations data collected from all monitoring stations,as well as sorted all questionnaire data of 39054 cases from the four cities in our cohort.2.Using SPSS16.0 statistical software package,we conducted t test,analysis of variance(ANOVA)and chi-square test to analyze the difference between different variables.We used Cox proportional hazards models to analyze the associations between different pollutants and disease mortality.Before and after adjusted some covariates,we estimate the effects of PM10 and SO2 on the mortality of lung cancer and nonmalignant respiratory.Results: 1.The 12-year range and average concentrations(1998-2009)of PM10 and SO2 were 90.64-274.00,11.00-224.40 and 144.34,66.90?g/m3,respectively.2.The entire study population included 39,054 participants contributing 462,177 person-years at risk(average time of follow-up is 11.83 years)with a total of 1435(3.5%)deaths.Of them,there are 140(0.4%)deaths of lung cancer,and 46(0.1%)deaths of COPD during the follow-up period.3.In the model of average pollution for the surviving period(APSP),PM10 and SO2 can bring an increase to the relative risk of lung cancer mortality(HR=1.653,1.224).We found a similar result in the analysis of SO2-single-pollutant models.In the Pearson correlation analysis,the average pollution of PM10 was highly correlated with SO2(r=0.947).In the PM10 and SO2 bi-pollutant models,the results were consistent with the results of single-pollutant models.4.After adjusted for variables,the results of stratified analysis indicated that male population,younger than 60-year-old people,daily smoking > 20 cigarettes/day people,and passive smoking people were susceptible population who can be more easier to get lung cancer death when exposure to high levels of PM10.5.In the single-pollutant models,PM10 and SO2 can bring an increase to the relative risk of COPD mortality(1.563,1.356-1.801;1.146,1.047-1.254).After adding SO2 to the PM10-bi-pollutant models,the results were consistent with single-pollutant models.However,in the bi-pollutant model,there was no statistical significance between SO2 and COPD mortality(0.962,0.818-1.131).6.The results of stratified analysis indicated that high personal income people(3.277,2.074-5.178),occupational exposure people(4.845,2.389-9.764)and passive smoking people were susceptible population who could be easier to get COPD death when exposure to high levels of PM10.7.For SO2,no smoking people(1.163,1.038-1.303),low education level people(1.149,1.044-1.265),high personal income people(1.242,1.034-1.492),occupational exposure people(4.845,2.389-9.764)and passive smoking people(1.205,1.008-1.240)were susceptible population who could be easier to get COPD death.Conclusions: 1.Our study found that long-term exposure to PM10 and SO2 were independently associated with the all-cause mortality,lung cancer mortality,and COPD mortality after controlling for other risk factors.2.Our study revealed that male,younger than 60-year-old,daily smoking > 20 cigarettes/day,and passive smoking people were susceptible population who could be easier to get lung cancer death when exposure to high levels of PM10.High personal income,occupational exposure and passive smoking people were susceptible population who could be easier to get COPD death when exposure to high levels of PM10 and SO2.