热浪对死亡率的影响：空气污染的作用修饰和混杂。

Effects of heat waves on mortality: effect modification and confounding by air pollutants.

机构信息

From the aDepartment of Hygiene, Epidemiology and Medical Statistics, Medical School, University of Athens, Athens, Greece; bDepartment of Epidemiology, Regional Health Authority, Rome, Italy; cWHO Regional Office for Europe, Bonn, Germany; dDivision of Population Health Sciences and Education and MRC-HPA Centre for Environment and Health, St George's, University of London, London, United Kingdom; eCenter for Public Health Research, CSISP, Conselleria de Sanitat, Valencia, Spain; fCIBER de Epidemiología y Salud Pública, CIBERESP, Barcelona, Spain; gUniversity of Valencia, Spain; hCentre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain; iIMIM (Hospital del Mar Research Institute), Barcelona, Spain; jHelmholtz Zentrum München, German Research Center for Environmental Health, Institute of Epidemiology II, Munich, Germany; kDepartment of Environmental Health, French Institute for Public Health Surveillance, Paris, France; lNational Institute of Environmental Health, Budapest, Hungary; and mEpidemiology Unit, Local Health Authority, Milan, Italy.

出版信息

Epidemiology. 2014 Jan;25(1):15-22. doi: 10.1097/EDE.0b013e31828ac01b.

DOI:10.1097/EDE.0b013e31828ac01b

PMID:24162013

Abstract

BACKGROUND

Heat waves and air pollution are both associated with increased mortality. Their joint effects are less well understood.

METHODS

We explored the role of air pollution in modifying the effects of heat waves on mortality, within the EuroHEAT project. Daily mortality, meteorologic, and air pollution data from nine European cities for the years 1990-2004 were assembled. We defined heat waves by taking both intensity and duration into account. The city-specific effects of heat wave episodes were estimated using generalized estimating equation models, adjusting for potential confounders with and without inclusion of air pollutants (particles, ozone, nitrogen dioxide, sulphur dioxide, carbon monoxide). To investigate effect modification, we introduced an interaction term between heat waves and each single pollutant in the models. Random effects meta-analysis was used to summarize the city-specific results.

RESULTS

The increase in the number of daily deaths during heat wave episodes was 54% higher on high ozone days compared with low, among people age 75-84 years. The heat wave effect on high PM10 days was increased by 36% and 106% in the 75-84 year and 85+ year age groups, respectively. A similar pattern was observed for effects on cardiovascular mortality. Effect modification was less evident for respiratory mortality, although the heat wave effect itself was greater for this cause of death. The heat wave effect was smaller (15-30%) after adjustment for ozone or PM10.

CONCLUSIONS

The heat wave effect on mortality was larger during high ozone or high PM10 days. When assessing the effect of heat waves on mortality, lack of adjustment for ozone and especially PM10 overestimates effect parameters. This bias has implications for public health policy.

摘要

背景

热浪和空气污染都会导致死亡率上升。但它们共同的影响还不太清楚。

方法

我们在 EuroHEAT 项目中探索了空气污染在改变热浪对死亡率的影响方面的作用。我们收集了 1990 年至 2004 年 9 个欧洲城市的每日死亡率、气象和空气污染数据。我们通过同时考虑强度和持续时间来定义热浪。使用广义估计方程模型估计热浪事件对每个城市的具体影响，在不包括和包括空气污染物（颗粒物、臭氧、二氧化氮、二氧化硫、一氧化碳）的情况下，调整潜在的混杂因素。为了研究效应修饰，我们在模型中引入了热浪与每种单一污染物之间的交互项。使用随机效应荟萃分析来总结各城市的具体结果。

结果

在 75-84 岁年龄组中，与臭氧水平低的日子相比，臭氧水平高的日子热浪期间每日死亡人数增加了 54%；在 75-84 岁和 85 岁以上年龄组中，高 PM10 日的热浪效应分别增加了 36%和 106%。心血管死亡率也观察到类似的模式。尽管这种死因的热浪效应更大，但对呼吸死亡率的效应修饰作用不太明显。调整臭氧或 PM10 后，热浪效应较小（15-30%）。