title: The interactive effects between high temperature and air pollution on mortality: A time-series analysis in Hefei, China.
abstract: Recent evidence suggests that there may be an interaction between air pollution and heat on mortality, which is pertinent in the context of global climate change. We sought to examine this interaction in Hefei, a hot and polluted Chinese city. We conducted time-series analyses using daily mortality, air pollutant concentration (including particulate matter with aerodynamic diameter <10μm (PM10), sulphur dioxide (SO2) and nitrogen dioxide (NO2)), and temperature data from 2008 to 2014. We applied quasi-Poisson regression models with natural cubic splines and examined the interactive effects using temperature-stratified models. Subgroup analyses were conducted by age, gender, and educational levels. We observed consistently stronger associations between air pollutants and mortality at high temperatures than at medium temperatures. These differences were statistically significant for the associations between PM10and non-accidental mortality and between all pollutants studied and respiratory mortality. Mean percentage increases in non-accidental mortality per 10μg/m3at high temperatures were 2.40% (95% confidence interval: 0.64 to 4.20) for PM10, 7.77% (0.60 to 15.00) for SO2, and 6.83% (-1.37 to 15.08) for NO2. The estimates for PM10were 3.40% (0.96 to 5.90) in females and 4.21% (1.44 to 7.05) in the illiterate, marking them as more vulnerable. No clear trend was identified by age. We observed an interaction between air pollutants and high temperature on mortality in Hefei, which was stronger in females and the illiterate. This may be due to differences in behaviours affecting personal exposure to high temperatures and has potential policy implications.
authors.affiliation: School of Medicine, The University of Auckland, Auckland, New Zealand. Electronic address: rqin006@aucklanduni.ac.nz.
authors.forename: Rennie Xinrui
authors.initials: RX
authors.lastname: Qin
authors.affiliation: Hefei Center for Disease Control and Prevention, Hefei, China. Electronic address: 734820892@qq.com.
authors.forename: Changchun
authors.initials: C
authors.lastname: Xiao
authors.affiliation: Hefei Center for Disease Control and Prevention, Hefei, China. Electronic address: 914402802@qq.com.
authors.forename: Yibin
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: 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; Changping District Center for Disease Control and Prevention, Beijing 102200, China. Electronic address: lijing986169323@sina.cn.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.affiliation: 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: smart_yjun@163.com.
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
authors.affiliation: 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; Ningbo Center for Disease Control and Prevention, Ningbo, China. Electronic address: gushaohua1989@126.com.
authors.forename: Shaohua
authors.initials: S
authors.lastname: Gu
authors.affiliation: Hefei Center for Disease Control and Prevention, Hefei, China. Electronic address: 634635760@qq.com.
authors.forename: Junrui
authors.initials: J
authors.lastname: Xia
authors.affiliation: Anhui Provincial Center for Disease Control and Prevention, Hefei, China. Electronic address: sub@ahcdc.com.cn.
authors.forename: Bin
authors.initials: B
authors.lastname: Su
authors.affiliation: 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.
authors.forename: Qiyong
authors.initials: Q
authors.lastname: Liu
authors.affiliation: School of Population Health, The University of Auckland, Auckland, New Zealand. Electronic address: a.woodward@auckland.ac.nz.
authors.forename: Alistair
authors.initials: A
authors.lastname: Woodward
mesh_terms: D000393:Air Pollutants; D000397:Air Pollution; D002681:China / Q000453:epidemiology; D057231:Climate Change; D005260:Female; D006801:Humans; D008297:Male; D009026:Mortality; D009585:Nitrogen Dioxide; D052638:Particulate Matter; D013458:Sulfur Dioxide; D013696:Temperature; D013997:Time Factors
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D013458:Sulfur Dioxide; D009585:Nitrogen Dioxide
keywords: Air pollution; China; Hot temperature; Interaction; Mortality; Time-series analysis