Heat wave-related excess mortality assessment in Shanghai,in summer 2013

Objective Based on the analysis of the relationship between the Shanghai heat wave in 2013 and local mortality data,quantitative evaluation of the excess mortality risk was conducted, which could provide the quantified information for disease control and prevention. Methods The daily heat-related morality was calculated by using the daily maximum and average temperature data during 2003-2013 summer days and the heat effects of temperature-mortality coefficient in Shanghai recorded in previous study. The annual heat-related excess mortality in summer and the annual excess mortality of heat wave period were also calculated and considered as the two targets of health risk assessment. Compared these results in 2013 to 2003-2012, the health risk level caused by Shanghai heat wave in 2013 was identified. Result There were 44 hot days during 2013 summer in Shanghai, especially 38 heat wave days in total, which was significantly beyond each year during 2003-2012.The total excess mortality of Shanghai in 2013 summer was 1 889 per year, which was 2.2 times of that in 2003-2012. The excess mortality caused by heat wave was 1 347 per year, which was 71.3% of the total excess mortality and 3.9 times of the average excess mortality during heat waves in the past decade. Conclusion Heat waves happened in 2013 summer in Shanghai are of high intensity, long duration and cause much higher excess mortality risk than the average mortality risk value during 2003-2012,which indicate the necessity to take public health protection to control the heat-related health risk in the future.