Associations Between Long-term Exposure To Fine Particulate Matters And Risk Of Cardiovascular Mortality

Background and ObjectivesMany population-based cohort studies have been conducted in European and American countries,the results of these studies provided sufficient evidence for associations between long-term exposure to ambient fine particulate matters and elevated cardiovascular mortality.In Asian countries,especially China,although people were exposed to high air pollution concentrations,the evidence on the chronic health effects of fine particles was limited.In order to explore associations between long-term PM2.5 exposure and cardiovascular mortality,and identify susceptible subgroups of the chronic effects of air pollution among Chinese adults,we matched data from 2010-2011 survey of China Chronic Disease and Risk Factors Surveillance and The China Disease Surveillance Points System.MethodsData on personal characteristics and prevalence of chronic diseases of 61768 participants aged ≥ 40 years included in this study were derived from 2010-2011 survey of China Chronic Disease and Risk Factors Surveillance.The estimated annual average concentrations of fine particles in each disease surveillance point from 1990 to 2013 were distracted from Global Burden of Disease Study 2013.The participants were followed up from 2011 to 2015,baseline data for each person from database of China Chronic Disease and Risk Factors Surveillance and death records from The China Disease Surveillance Points System were automatic matched by computer checking algorithm,while using data from field investigation as supplement.We combined these two methods together to obtain follow-up outcomes of participants.Cox proportional hazards regression models were used to estimate the relationships between long-term exposure to fine particles and cardiovascular mortality among Chinese adults aged ≥ 40 years,adjusting for several confounding factors.ResultsA total number of 61768 participants were followed up for 5 years from 2011 to 2015.During this period,2801 deaths(1411 men and 1390 women)occurred.Of these deaths,1205 were attributed to CVD,416 were attributed to IHD and 663 were attributed to cerebrovascular diseases.The DSP-level average of PM2.5 in 2010 ranged from 1.71 to 92.04μg/m3,and the mean level of PM2.5 exposure of 161 DSPs was 47.29 μg/m3 in 2010.After adjusting for age,gender,educational levels,marital status,smoking and drinking status,household air pollution,body mass index,hypertension prevalence,urban-rural and geographic area and other several confounding factors,we failed to detect significant associations between long-term fine particles exposure and cardiovascular mortality.Per 10μg/m3 increased in PM2.5 was not significantly associated with mortality from CVD(HR=1.014;95%CI:0.981,1.047),IHD(HR=1.043;95%CI:0.986,1.104)and cerebrovascular diseases(HR=1.031;95%CI:0.987,1.078).Using different periods of pollutants concentrations as indications of residents’ exposure estimations,or using different inclusion criteria for participants,the results were similar.In the analyses on the susceptible factors,we found that each 10 μg/m3 increase of PM2.5 was associated with increases of 10.8%(HR=1,108;95%CI:1.008,1.127)and 20.0%(HR=1.200;95%CI:1.053,1.368)in CVD mortality and cerebrovascular mortality among adults in past-smokers ≥ 40 years of age,respectively.Each 10 μg/m3 increase of PM2.5 was associated with increases of 7.1%(HR=1.071;95%CI:1.009,1.137)and 15.7%(HR=1.157;95%CI:1.067,1.256)in CVD mortality and cerebrovascular mortality among adults ≥ 40 years of age in eastern China,respectively.Furthermore,significant associations were found between PM2.5 and IHD mortality in people who were overweight,or lived in rural areas or central China in baseline.ConclusionUsing the combination methods of database matching and field investigation to obtain survival status of participants from 2010-2011 survey of China Chronic Disease and Risk Factors Surveillance,we failed to detect significant associations between PM2.5 exposure and CVD,IHD or cerebrovascular mortality among Chinese adults aged ≥ 40 years.But we found significant associations between PM2.5 exposure and CVD,cerebrovascular mortality among past smokers and eastern residents.Significant associations between PM2.5 exposure and IHD mortality were also found among overweight residents,rural residnets and participants in central China.