ABSTRACT
Abstract Increased frequency of heat waves (HWs) is one of the prominent consequences of climate change. Its impact on human health has been mostly reported in the northern hemisphere but has been poorly studied in the southern hemisphere. The aim of this study was to analyze the effects of the HWs waves occurred in the warm season 2013-14 on mortality in the center-north region of Argentina, where 22 million people live. It was carried out an observational study of ecological-type contrasting the mortality occurred during the HWs of the summer 2013-14 with the mortality in the summers 2010-11 to 2012-13, free from HWs. The mortality was analyzed according to the following variables: place of residence, age, sex and cause of death. During the HWs of the summer 2013-14, 1877 (RR=1.23, 95%CI 1.20-1.28) deaths in excess were registered. Moreover, the death risk significantly increased in 13 of the 18 provinces analyzed. The mortality rates by sex revealed heterogeneous behaviour regarding both the time and spatial scale. The death risk increased with age; it was particularly significant in four provinces for the 60-79 years group and in six provinces in people of 80 years and over. The death causes that showed significantly increments were respiratory, cardiovascular, renal diseases and diabetes.
Resumo O aumento da frequência das ondas de calor (OsC) é uma das consequências proeminentes das alterações climáticas. O seu impacto na saúde humana tem sido relatado principalmente no hemisfério norte, mas tem sido mal estudado no hemisfério sul. O objetivo deste estudo foi analisar os efeitos das OsC ocorridas no verão de 2013-14 sobre a mortalidade na região centro-norte da Argentina, onde 22 milhões de pessoas vivem. Foi realizado um estudo observacional de tipo ecológico que contrasta a mortalidade ocorrida durante as OsC do verão 2013-14 com a mortalidade nos verões 2010-11 a 2012-13. A mortalidade foi analisada de acordo com local de residência, idade, sexo e causa de morte. Durante as OsC do verão de 2013-14, registaram-se 1.877 (RR=1.23, 95%IC 1.20-1.28) mortes em excesso. O risco de morte (RM) aumentou significativamente em 13 das 18 províncias analisadas. As taxas de mortalidade por sexo revelaram um comportamento heterogêneo tanto no tempo como na escala espacial. O RM foi aumentado com a idade; este aumento foi particularmente significativo em quatro províncias para o grupo de 60-79 anos e em seis províncias em pessoas com mais de 80 anos. As causas de morte que mostraram significativamente incrementos foram: doenças respiratórias, cardiovasculares, renais e diabetes.
ABSTRACT
Background Stroke has become a main cause of death in China. With global warming, the studies on temperature and stroke have attracted much attention. Objective To analyze he relationships between heatwave and the years of life lost (YLL) by different subtypes of stroke by controlling temporal and spatial effects with Bayesian spatio-temporal model, and to study the modifiers of the health effect of heatwave. Methods The daily information of stroke deaths, meteorological data, and air pollutant data in 40 districts and counties of Guangdong Province were collected during the warm seasons (from May to October) in the years from 2014 to 2017. The individual YLL was first calculated by matching age and gender according to the life table, and then the daily YLL rate (person-years/100 000 people) was obtained by summarizing the daily YLL and correcting it with the population of each district or county. Bayesian spatio-temporal model was used to fit a proposed exposure-response relationship between heatwave and the YLL rates of different subtypes of stroke. Finally, stratified analyses were conducted by age (<65 years, ≥65 years), gender (male, female), and region (Pearl River Delta and non-Pearl River Delta regions) to identify the major modifiers for the association between heatwave and stroke mortality. Results During the warm seasons from 2014 to 2017, a total of 23 heatwave events occurred in the 40 districts or counties of Guangdong Province, cumulatively lasting for 145 d. A total of 30 852 stroke deaths were recorded in the same time periods. The average daily YLL rate of total stroke was (2.39±3.63) person-years/100 000 people, and those for hemorrhagic stroke and ischemic stroke were (1.54±2.99) person-years/100 000 people and (0.84±1.85) person-years/100 000 people, respectively. Heatwave was associated with increased YLL rate of stroke in residents, and it had a greater impact on ischemic stroke with a lag effect. The largest cumulative effect of heatwave was at lag 0-1 day, which was associated with an increased YLL rate of total stroke and ischemic stroke by 0.17 (95%CI: 0.03-0.29) person-years/100 000 people and 0.13 (95%CI: 0.06-0.20) person-years/100 000 people, respectively. The results of stratified analyses showed that heatwave had a larger effect on ischemic stroke in residents of aged 65 years or older, male, and non-Pearl River Delta regions, and the rates of YLL increased by 1.11 (95%CI: 0.58-1.55), 0.13 (95%CI: 0.03-0.23), and 0.20 (95%CI: 0.07-0.32) person-years/100 000 people, respectively; Heatwave only had an effect on hemorrhagic stroke in residents aged 65 years or older with an increased YLL rate of 0.79 (95%CI: 0.26-1.31) person-years/100 000 people. Conclusion Heatwave could elevate the level of years of life lost associated with stroke in Guangdong residents, with greater impacts on ischemic stroke of the aged, men, and residents in non-Pearl River Delta regions, and on hemorrhagic stroke in the elderly.
ABSTRACT
In the context of global warming, the frequency, intensity, and duration of heatwaves will further increase. In recent years, plenty of studies have suggested from diversiform perspectives that heatwaves may increase mortality risk. However, the focuses of current studies on heat wave and human health are scattered, and a systematic theoretical framework has not yet been formed. We therefore systematically reviewed the previous literature in terms of possible mechanism paths and vulnerability mechanism of heatwave increasing mortality risk, summarized the vulnerability factors that influence exposure opportunities, constrain adaptive capacity, as well as affect physiological responses and behaviors. We further attempted to propose a theoretical framework from the processes of "exposure degree-modification effect-physiological behavior-health outcome". This paper summarized the research directions on heatwaves and health, which can provide ideas for future in-depth health risk assessment and adaptation to climate change.
ABSTRACT
Objective@#To evaluate the intervention effects of response to heatwave in communities of four cities, China.@*Methods@#Baseline survey on heatwave and climate change related knowledge, attitude and practice (KAP) was conducted in the pilot communities in Harbin, Nanjing, Shenzhen and Chongqing, using face-to-face questionnaire interview in November, 2011 to November, 2013. Finally, 1 604 residents were interviewed. Intervention measures were implemented in summers of 2013 and 2014, including delivering early warning information of heatwave health risk and launching health education and promotion. The second survey was conducted in same communities using the same questionnaire and sampling method as baseline survey in November, 2014, and 1 640 residents were interviewed. The Chi-square test was used to compare the demographic characteristics and KAP of community residents between before and after intervention, and the factors that affected the intervention effect were selected by logistic multiple stepwise regression model.@*Results@#The age of the residents interviewed before and after intervention was (46.4 ± 15.5) years and (45.0 ± 15.9) years, respectively. Overall, the residents' awareness rates of heatwave before and after intervention were 70.5% (1 131/1 604) and 82.9% (1 359/1 640) (χ2=69.40, P<0.001). The rate of residents who had wished to receive early warning information increased 6.3% (χ2=41.11, P<0.001), which reached 94.6% (1 551/1 604) after intervention from 88.3% (1 416/1 604) in baseline survey. Both heatwave health risk early warning and health education had big impacts to residents. There were 92.7% (1 105 residents) among the 1 192 residents who had received the early warning information arrange work and rest time according to the early warning information and 93.0% (1 231 residents) among the 1 323 residents who knew about health education activities being conducted in community thought that the community health education activities had made active role in protecting health from heatwaves. After a series of intervention, male had a effect on attitude about hot wave than female in Nanjing and Chongqing, OR (95%CI) were 1.48(1.02-2.16) and 1.45 (1.18-2.05) , respectively; compared with subjects below primary school education, people with college degree or above had higer KAP in all cities (ORs range from 1.18 to 2.05), P<0.05; regular physical exercise (ORs range from 1.39 to 2.70) also had profound impacts on KAP in all cities (P<0.05).@*Conclusion@#s Early warning and health education were effective measures to enhance residents' response capacity to climate change.