Acute effects of diurnal temperature range on mortality in 8 Chinese cities

• Published in: The Science of the total environment Vol. 493; pp. 92 - 97
• Main Authors: Zhou, Xiaodan, Zhao, Ang, Meng, Xia, Chen, Renjie, Kuang, Xingya, Duan, Xiaoli, Kan, Haidong
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.09.2014; Elsevier
• Subjects: Aged; Air pollution; Biological and medical sciences; Cardiovascular Diseases - mortality; China; China - epidemiology; Climate Change; Cool season; Death; Diurnal temperature range; Environment. Living conditions; Female; Humans; Male; Medical sciences; Mortality; Mortality - trends; Policies; Public health. Hygiene; Public health. Hygiene-occupational medicine; Relative humidity; Temperature; Time-series; Asia; China; China, People's Rep; Diurnal temperature range; Climate change; Time-series; Mortality; Toxicity; Acute; Time series; Temperature effect; Urban area; Diurnal variation; Dynamical climatology; Global change; Time-series analysis
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2014.05.116

Diurnal temperature range (DTR) is a meteorological indicator closely associated with global climate change. There have been no multicity studies in China addressing the DTR-related health impact. We hypothesized that an increase of DTR is associated with higher daily mortality with a potential lag of effect, and investigated the acute effects of DTR on total, cardiovascular, and respiratory mortality in 8 large Chinese cities from 2001 to 2010. We first calculated city-specific effect of DTR in the full year, the cool season (November to the next April) and the warm season (May to October) separately using a semi-parametric generalized additive model; then we pooled the city-specific estimates with meta analysis. After adjusting for long-term and seasonal trends, temperature, relative humidity and air pollution levels, we found statistically significant associations between DTR and daily mortality, especially in cool seasons. A 1°C increment of DTR on lag-day 1 corresponded to a 0.42% (95% CI, 0.14 to 0.70) increase in total non-accidental mortality, 0.45% (95% CI, 0.26 to 0.65) increase in cardiovascular mortality, and a 0.76% (95% CI, 0.24 to 1.29) increase in respiratory mortality in cool seasons. Deaths among females and elderly (≥65years) were more strongly associated with DTR than among males and younger people (<65years). Our analysis suggests that DTR is a potential trigger for death in China. Our findings may have important implications for the climate policies in the country.