High Temperatures Enhanced Acute Mortality Effects of Ambient Particle Pollution in the "Oven" City of Wuhan, China Zhengmin Qian,1,2 Qingci He,3 Hung-Mo Lin,1,4 Lingli Kong,3 Christy M. Bentley,1 Wenshan Liu,5 and Dunjin Zhou6 1Department of Public Health Sciences, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA; 2Geisinger Center for Health Research, Danville, Pennsylvania, USA; 3Wuhan Academy of Environmental Science, Wuhan, China; 4Mount Sinai School of Medicine, New York, NY, USA; 5Wuhan Environmental Monitoring Center, Wuhan, China; 6Wuhan Centres for Disease Prevention and Control, Wuhan, China Abstract Background: We investigated whether the effect of air pollution on daily mortality is enhanced by high temperatures in Wuhan, China, using data from 2001 to 2004. Wuhan has been called an "oven" city because of its hot summers. Approximately 4.5 million permanent residents live in the 201-km2 core area of the city. Method: We used a generalized additive model to analyze pollution, mortality, and covariate data. The estimates of the interaction between high temperature and air pollution were obtained from the main effects and pollutant–temperature interaction models. Results: We observed effects of consistently and statistically significant interactions between particulate matter ≤ 10 µm (PM10) and temperature on daily nonaccidental (p = 0.014) , cardiovascular (p = 0.007) , and cardiopulmonary (p = 0.014) mortality. The PM10 effects were strongest on extremely high-temperature days (daily average temperature, 33.1°C) , less strong on extremely low-temperature days (2.2°C) , and weakest on normal-temperature days (18.0°C) . The estimates of the mean percentage of change in daily mortality per 10-µg/m3 increase in PM10 concentrations at the average of lags 0 and 1 day during hot temperature were 2.20% (95% confidence interval) , 0.74–3.68) for nonaccidental, 3.28% (1.24–5.37) for cardiovascular, 2.35% (–0.03 to 4.78) for stroke, 3.31% (–0.22 to 6.97) for cardiac, 1.15% (–3.54% to 6.07) for respiratory, and 3.02% (1.03–5.04) for cardiopulmonary mortality. Conclusions: We found synergistic effects of PM10 and high temperatures on daily nonaccidental, cardiovascular, and cardiopulmonary mortality in Wuhan. Key words: air pollution, China, health effect, mortality, temperature. Environ Health Perspect 116:1172–1178 (2008) . doi:10.1289/ehp.10847 available via http://dx.doi.org/ [Online 9 July 2008] Address correspondence to Z. Qian, Geisinger Center for Health Research, M.C. 44-00, Danville, PA 17822 USA. Telephone (570) 214-6594. Fax: (570) 214-5170. E-mail: zqian1@geisinger.edu We thank E. Lehman and D. Liao for their assistance and support. This research was conducted under contract to the Health Effects Institute (4710-RFIQ03-3/04-6) . The contents of this article do not necessarily reflect the views of the funding agencies. The authors declare they have no competing financial interests. Received 5 September 2007 ; accepted 26 June 2008. The full version of this article is available for free in HTML or PDF formats. |