Seasonal variation of chemical species associated with short-term mortality effects of PM(2.5) in Xi'an, a Central City in China.
The authors conducted a time-series analysis to examine seasonal variation of mortality risk in association with particulate matter less than 2.5 μm in aerodynamic diameter (PM(2.5)) and chemical species in Xi'an, China, using daily air pollution and all-cause and cause-specific mortality data (2004-2008). Poisson regression incorporating natural splines was used to estimate mortality risks of PM(2.5) and its chemical components, adjusting for day of the week, time trend, and meteorologic effects. Increases of 2.29% (95% confidence interval: 0.83, 3.76) for all-cause mortality and 3.08% (95% confidence interval: 0.94, 5.26) for cardiovascular mortality were associated with an interquartile range increase of 103.0 μg/m(3) in lagged 1-2 day PM(2.5) exposure. Stronger effects were observed for the elderly (≥65 years), males, and cardiovascular diseases groups. Secondary components (sulfate and ammonium), combustion species (elemental carbon, sulfur, chlorine), and transition metals (chromium, lead, nickel, and zinc) appeared most responsible for increased risk, particularly in the cold months. The authors concluded that differential association patterns observed across species and seasons indicated that PM(2.5)-related effects might not be sufficiently explained by PM(2.5) mass alone. Future research is needed to examine spatial and temporal varying factors that might play important roles in modifying the PM(2.5)-mortality association.
College of Environmental Sciences and Engineering and Center for Environment and Health, Beijing, China.
Wei
W
Huang
Junji
J
Cao
Yebin
Y
Tao
Lingzhen
L
Dai
Shou-En
SE
Lu
Bin
B
Hou
Zheng
Z
Wang
Tong
T
Zhu
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000393:Air Pollutants / Q000032:analysis / Q000737:chemistry / Q000633:toxicity*; D000397:Air Pollution / Q000009:adverse effects* / Q000032:analysis / Q000706:statistics & numerical data; D002318:Cardiovascular Diseases / Q000401:mortality; D002423:Cause of Death; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D004781:Environmental Exposure / Q000009:adverse effects* / Q000032:analysis / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D009026:Mortality; D052638:Particulate Matter / Q000032:analysis / Q000737:chemistry / Q000633:toxicity*; D016012:Poisson Distribution; D012044:Regression Analysis; D012621:Seasons; D012737:Sex Factors; D055815:Young Adult
D000393:Air Pollutants; D052638:Particulate Matter