温度改变了中国八个城市中颗粒物空气污染对死亡率的急性影响。

Temperature modifies the acute effect of particulate air pollution on mortality in eight Chinese cities.

机构信息

School of Public Health, Key Lab of Public Health Safety of the Ministry of Education, Fudan University, Shanghai, China.

出版信息

Sci Total Environ. 2012 Oct 1;435-436:215-21. doi: 10.1016/j.scitotenv.2012.07.008. Epub 2012 Jul 31.

DOI:10.1016/j.scitotenv.2012.07.008

PMID:22854092

Abstract

BACKGROUND

Both temperature and particulate air pollution are associated with increased death risk. However, whether the effect of particulate air pollution on mortality is modified by temperature remains unsettled.

METHODS

A stratified time-series analysis was conducted to examine whether the effects of particulate matter less than 10 μm in aerodynamic diameter (PM(10)) on mortality was modified by temperature in eight Chinese cities. Poisson regression models incorporating natural spline smoothing functions were used to adjust for long-term and seasonal trends of mortality, as well as other time-varying covariates. The bivariate response surface model was applied to visually examine the potential interacting effect. The associations between PM(10) and mortality were stratified by temperature to examine effect modification.

RESULTS

The averaged daily concentrations of PM(10) in the eight Chinese cities ranged from 65 μg/m(3) to 124 μg/m(3), which were much higher than in Western countries. We found evidence that the effects of PM(10) on mortality may depend on temperature. The eight-city combined analysis showed that on "normal" (5th-95th percentile) temperature days, a 10-μg/m(3) increment in PM(10) corresponded to a 0.54% (95% CI, 0.39 to 0.69) increase of total mortality, 0.56% (95% CI, 0.36 to 0.76) increase of cardiovascular mortality, and 0.80% (95% CI, 0.64 to 0.96) increase of respiratory mortality. On high temperature (>95th percentile) days, the estimates increased to 1.35% (95% CI, 0.80 to 1.91) for total mortality, 1.57% (95% CI, 0.69 to 2.46) for cardiovascular mortality, and 1.79% (95% CI, 0.75 to 2.83) for respiratory mortality. We did not observe significant effect modification by extreme low temperature.

CONCLUSIONS

Extreme high temperature increased the associations of PM(10) with daily mortality. These findings may have implication for the health impact associated with both air pollution and global climate change.

摘要

背景

温度和颗粒物空气污染都与死亡风险增加有关。然而，颗粒物空气污染对死亡率的影响是否受温度的影响仍未得到解决。

方法

采用分层时间序列分析，在中国 8 个城市研究了小于 10 μm 空气动力学直径的颗粒物（PM（10））对死亡率的影响是否受温度的影响。采用泊松回归模型，结合自然样条平滑函数，调整死亡率的长期和季节性趋势以及其他时变协变量。应用双变量响应面模型直观地检查潜在的交互作用。按温度对 PM（10）与死亡率的关系进行分层，以检验效应修饰。

结果

8 个中国城市的 PM（10）平均日浓度范围为 65μg/m（3）至 124μg/m（3），远高于西方国家。我们有证据表明，PM（10）对死亡率的影响可能取决于温度。8 个城市的综合分析表明，在“正常”（第 5 至 95 百分位数）温度日，PM（10）每增加 10μg/m（3），总死亡率增加 0.54%（95%置信区间，0.39%至 0.69%），心血管死亡率增加 0.56%（95%置信区间，0.36%至 0.76%），呼吸死亡率增加 0.80%（95%置信区间，0.64%至 0.96%）。在高温日（>第 95 百分位数），总死亡率估计值增加到 1.35%（95%置信区间，0.80%至 1.91%），心血管死亡率增加到 1.57%（95%置信区间，0.69%至 2.46%），呼吸死亡率增加到 1.79%（95%置信区间，0.75%至 2.83%）。我们没有观察到极端低温对效应修饰的显著影响。