The burden of air pollution on years of life lost in Beijing, China, 2004-08: retrospective regression analysis of daily deathsBMJ 2013; 347 doi: https://doi.org/10.1136/bmj.f7139 (Published 09 December 2013) Cite this as: BMJ 2013;347:f7139
- Yuming Guo, research fellow1,
- Shanshan Li, PhD candidate1,
- Zhaoxing Tian, doctor of emergency medicine2,
- Xiaochuan Pan, professor of environmental health3,
- Jinliang Zhang, professor of environmental health4,
- Gail Williams, professor of international health and statistics1
- 1Department of Epidemiology and Biostatistics, School of Population Health, University of Queensland, Brisbane, QLD 4006, Australia
- 2Emergency Department of Peking University Third Hospital, Beijing 100191, China
- 3Department of Occupational and Environmental Health, Peking University School of Public Health, Beijing, China
- 4State Key Laboratory of Environmental Criteria and Risk Assessment, Environmental Standards Institute, Chinese Research Academy of Environmental Sciences, Beijing, China
- Correspondence to: Y Guo , Z Tian
- Accepted 14 November 2013
Objectives To better understand the burden of air pollution on deaths, we examined the effects of air pollutants on years of life lost (YLL) in Beijing, China.
Design Retrospective regression analysis using daily time series.
Setting 8 urban districts in Beijing, China.
Participants 80 515 deaths (48 802 male, 31 713 female) recorded by the Beijing death classification system during 2004-08.
Main outcome measures Associations between daily YLL and ambient air pollutants (particulate matter with aerodynamic diameter <2.5 µm (PM2.5), PM10, SO2, and NO2), after adjusting for long term trends, seasonality, day of the week, and weather conditions. We also examined mortality risk related to air pollutants.
Results Mean concentrations of daily PM2.5, PM10, SO2 and NO2 were 105.1 μg/m3, 144.6 μg/m3, 48.6 μg/m3, and 64.2 μg/m3, respectively. All air pollutants had significant effects on years of life lost when we used single pollutant models. An interquartile range (IQR) increase in PM2.5, PM10, SO2, and NO2 was related to YLL increases of 15.8, 15.8, 16.2, and 15.1 years, respectively. The effects of air pollutants on YLL appeared acutely and lasted for two days (lag 0-1); these effects associated with an IQR increase in PM2.5 were greater in women than men (11.1 (95% confidence interval 4.7 to 17.5) v 4.7 (−2.9 to 12.3) YLL) and in people aged up to 65 years than those older than 65 years (12.0 (2.9 to 21) v 3.8 (−0.9 to 8.6) YLL). The mortality risk associated with an IQR increase in PM2.5 was greater for people older than 65 years (2.5% (95% confidence interval 0.6% to 4.5%) increase of mortality) than those aged up to 65 years (0.7% (−0.8% to 2.2%)).
Conclusions YLL provides a complementary measure for examining the effect of air pollutants on mortality. Increased YLL are associated with increased air pollution. This study highlights the need to reduce air pollution in Beijing, China, to protect the health of the population.
We thank the Beijing Municipal Environmental Monitoring Centre for providing air pollution data (PM10, SO2, and NO2), China Meteorological Data Sharing Service System for providing meteorology data, and Beijing Public Security Bureau for providing mortality data
Contributors: YG and GW were involved in the design of the study. YG, SL, ZT, and XP prepared and cleaned the data. YG did the statistical analysis and wrote the first draft. SL, ZT, XP, JZ, and GW helped revise the paper. YG and GW are the guarantors for the study. YG, ZT, and XP had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.
Funding: This study is funded by the National Natural Science Foundation of China (#81172745), and the Australia National Health and Medical Research Council (#APP1030259).
Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf and declare: support from the National Natural Science Foundation of China and the Australia National Health and Medical Research Council for the submitted work; YG is supported by the Centre for Air Quality and Health Research and Evaluation and the University of Queensland School of Population Health; no other relationships or activities that could appear to have influenced the submitted work.
Ethical approval: This study was approved by the University of Queensland’s behaviour and social sciences ethical review committee (2013000739).
Data sharing: Data on life expectancy and an example dataset showing how to calculate years of life lost are available in the web appendix. Statistical codes are available from the corresponding author at.
The lead authors affirm that the manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned (and, if relevant, registered) have been explained.
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