Ambient Fine Particulate Matter Exposure and Risk of Cardiovascular Mortality: Adjustment of the Meteorological Factors.
Few studies have explicitly explored the impacts of the extensive adjustment (with a lag period of more than one week) of temperature and humidity on the association between ambient fine particulate matter (PM2.5) and cardiovascular mortality. In a time stratified case-crossover study, we used a distributed lag nonlinear model to assess the impacts of extensive adjustments of temperature and humidity for longer lag periods (for 7, 14, 21, 28 and 40 days) on effects of PM2.5on total cardiovascular mortality and mortality of cerebrovascular and ischemic heart disease and corresponding exposure-response relationships in Beijing, China, between 2008 and 2011. Compared with results only controlled for temperature and humidity for 2 days, the estimated effects of PM2.5were smaller and magnitudes of exposure-response curves were decreased when longer lag periods of temperature and relative humidity were included for adjustments, but these changes varied across subpopulation, with marked decreases occurring in males and the elderly who are more susceptible to PM2.5-related mortalities. Our findings suggest that the adjustment of meteorological factors using lag periods shorter than one week may lead to overestimated effects of PM2.5. The associations of PM2.5with cardiovascular mortality in susceptible populations were more sensitive to further adjustments for temperature and relative humidity.
Department of Epidemiology and Biostatistics, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing 100005, China. kevinluopumc@hotmail.com.|Center of Environmental and Health Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100005, China. kevinluopumc@hotmail.com.
Kai
K
Luo
Department of Epidemiology and Biostatistics, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing 100005, China. liwenjing197@163.com.|Center of Environmental and Health Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100005, China. liwenjing197@163.com.
Wenjing
W
Li
Department of Epidemiology and Biostatistics, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing 100005, China. zrm2018@126.com.|Center of Environmental and Health Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100005, China. zrm2018@126.com.
Ruiming
R
Zhang
College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China. lirk@ucas.ac.cn.|State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Science, Beijing 100101, China. lirk@ucas.ac.cn.
Runkui
R
Li
Department of Epidemiology and Biostatistics, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing 100005, China. xuqun@ibms.cams.cn.|Center of Environmental and Health Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100005, China. xuqun@ibms.cams.cn.
Qun
Q
Xu
Clinical Epidemiology and Biostatistics, School of Medical Sciences, Örebro University, Örebro 70185, Sweden. yang.cao@ki.se.|Unit of Biostatistics, Institute of Environmental Medicine, KarolinskaInstitutet, Stockholm 17177, Sweden. yang.cao@ki.se.
Yang
Y
Cao
D000368:Aged; D000393:Air Pollutants / Q000633:toxicity*; D000068476:Beijing / Q000453:epidemiology; D002318:Cardiovascular Diseases / Q000139:chemically induced / Q000401:mortality*; D002561:Cerebrovascular Disorders / Q000139:chemically induced / Q000401:mortality; D018592:Cross-Over Studies; D004781:Environmental Exposure; D006801:Humans; D006813:Humidity; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000139:chemically induced / Q000401:mortality; D017711:Nonlinear Dynamics; D010316:Particle Size; D052638:Particulate Matter / Q000633:toxicity*; D012307:Risk Factors; D013696:Temperature; D013997:Time Factors
D000393:Air Pollutants; D052638:Particulate Matter
PM2.5; distributed lag nonlinear model; fine particulate matter; mortality; time stratified case-crossover study