Hourly temperature variability and mortality in 31 major Chinese cities: Effect modification by individual characteristics, season and temperature zone

Zhou Yang; Jun Yang; Maigeng Zhou; Peng Yin; Zhaoyue Chen; Qi Zhao; Kejia Hu; Qiyong Liu; Chun-Quan Ou

doi:10.1016/j.envint.2021.106746

Hourly temperature variability and mortality in 31 major Chinese cities: Effect modification by individual characteristics, season and temperature zone

Environ Int. 2021 Nov:156:106746. doi: 10.1016/j.envint.2021.106746. Epub 2021 Jul 8.

Authors

Zhou Yang¹, Jun Yang², Maigeng Zhou³, Peng Yin³, Zhaoyue Chen¹, Qi Zhao⁴, Kejia Hu⁵, Qiyong Liu⁶, Chun-Quan Ou⁷

Affiliations

¹ State Key Laboratory of Organ Failure Research, Department of Biostatistics, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou 510515, China.
² Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China; Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 511443, China; JNU-QUT Joint Laboratory for Air Quality Science and Management, Jinan University, Guangzhou 511443, China. Electronic address: yangjun_eci@jnu.edu.cn.
³ National Center for Chronic and Noncommunicable Disease Control and Prevention, Beijing 100050, China.
⁴ Department of Epidemiology, Shandong University, Jinan, China.
⁵ Institute of Big Data in Health Science, School of Public Health, Zhejiang University, Hangzhou, 310058, China.
⁶ State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China. Electronic address: liuqiyong@icdc.cn.
⁷ State Key Laboratory of Organ Failure Research, Department of Biostatistics, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou 510515, China. Electronic address: ocq@smu.edu.cn.

PMID: 34247007
DOI: 10.1016/j.envint.2021.106746

Abstract

Background: In the context of ongoing climate change, temperature variability (TV) has been considered as an important trigger of death. However, evidence of association between mortality and hourly temperature variability (HTV) is scarce at the multi-city level, and the time window of health effects of HTV is lack of investigation. This study aims at quantifying the mortality risk and burden of HTV and exploring subpopulations susceptible to HTV from a large-scale multi-city perspective.

Methods: Data on daily number of deaths and meteorology were collected for 31 Chinese major cities during 2007-2013. HTV was calculated as the standard deviation of hourly temperature within a few days. The optimal exposure period of HTV was chosen according to multiple scientific criteria. A quasi-Poisson regression combined with distributed lag nonlinear model was used to assess the city-specific HTV-mortality associations. Then, meta-analysis was further applied to pool city-specific effect estimates. Finally, we calculated the fraction of mortality attributable to HTV. Stratification analyses were conducted by individual characteristics (i.e. age, sex, and educational attainment), season, and region.

Results: HTV calculated in a relatively long-time window like 18 d (HTV_0-17) could capture the impact of HTV adequately. Per 1 °C raise of HTV_0-17 associated with 1.38% (95%CI: 0.77, 1.99) increase of non-accidental mortality. During the study period, 5.47% (95%CI: 1.06, 9.64) of non-accidental mortality could be attributed to HTV. The females, the elderly, and individuals with low education level were more susceptible to HTV than their counterparts, respectively. Moreover, a stronger HTV-mortality association was observed in individuals who live in warmer season and temperature zone.

Conclusion: HTV is associated with a considerable mortality burden, which may be modified by season, geographic and individual-level factors. Our findings highlight the practical importance of establishing early warning systems and promoting health education to mitigate the impacts of temperature variability.

Keywords: Attributable fraction; China; Effect modifier; Hourly temperature variability; Mortality.

Publication types

Meta-Analysis
Research Support, Non-U.S. Gov't

MeSH terms

Aged
China / epidemiology
Cities
Climate Change*
Cold Temperature
Female
Hot Temperature*
Humans
Mortality
Seasons
Temperature