Projecting Future Heat-Related Mortality under Climate Change Scenarios: A Systematic Review
Huang, Cunrui, Gerard Barnett, Adrian, Wang, Xiaoming, Vaneckova, Pavla, FitzGerald, Gerard, Tong, Shilu, Environmental Health Perspectives
BACKGROUND: Heat-related mortality is a matter of great public health concern, especially in the light of climate change. Although many studies have found associations between high temperatures and mortality, more research is needed to project the future impacts of climate change on heat-related mortality.
Objectives: We conducted a systematic review of research and methods for projecting future heat-related mortality under climate change scenarios.
DATA SOURCES AND EXTRACTION: A literature search was conducted in August 2010, using the electronic databases PubMed, Scopus, ScienceDirect, ProQuest, and Web of Science. The search was limited to peer-reviewed journal articles published in English from January 1980 through July 2010.
DATA SYNTHESIS: Fourteen studiesrulfilled the inclusion criteria. Most projections showed that climate change would result in a substantial increase in heat-related mortality. Projecting heat-related mortality requires understanding historical temperature-mortality relationships and considering the future changes in climate, population, and acclimatization. Further research is needed to provide a stronger theoretical framework for projections, including a better understanding of socioeconomic development, adaptation strategies, land-use patterns, air pollution, and mortality displacement.
CONCLUSIONS: Scenario-based projection research will meaningftilly contribute to assessing and managing the potential impacts of climate change on heat-related mortality.
Key WORDS: climate change, heat wave, mortality, projection, public health, scenario. Environ Health Perspect 119:1681-1690 (2011). http://dx.doi.org/10.1289/ehp.1103456 [Online 4 August 2011]
Exposure to extreme heat has been associated with both increased mortality and morbidity. A number of epidemiological studies have examined high temperatures in relation to total nonaccidental deaths (McMichael et al. 2008; Stafoggia er al. 2006), ro cause-specific mortality (Barnett 2007; Hertel et al. 2009), and to other health outcomes such as emergency department visits and hospitalizations (Knowlton et al. 2009; Wang et al. 2009). In fact, heat waves are the biggest cause of weather-related fatalities in many cities, responsiblc for more deaths annually than any other form of extr[contains]me weather [Luber and McGeehin 2008; World Health Organization (WHO) 2009a].
Recently, heat-related mortality has become a matter of growing public health concern, especially because of climate change (Kovats and Hajat 2008; 0'NeiU and Ebi 2009). The Intergovernmental Panel on Climate Change (IPCC) indicates that hot weather is likely to increase future heat-re-Jared mortality (JPCC 2007a). Urban areas, home to more than half of the world's population (United Nations 2009), can be particularly vulnerable to heat because of high concentrations of susceptible people (Hajat et al. 2007), the urban heat island effect (Smargiassi et al. 2009), poor urban design and planning (Stone et al. 2010), and the interaction between air pollution and heat (ReneraJ.2006).
People with cardiovascukr or respiratory disease, diabetes, chronic mental disorders, or other preexisting medical conditions are at greater risk from heat exposure (Kovacs and Hajat 2008; WHO 2009a). The effects of heat are particularly strong in the elderly (Basu and Ostro 2008; Vaneckova et al. 2008a). Other factors that influence the risks of heat-related mortality include sociol isolation (Naughton et al. 2002; Semenza et al. 1996), low income (Kaiser et al. 2001), low education (0'Neill et al. 2003), poor housing (Vandentorren et al. 2006), lower access to air conditioning (0'Neill et al. 2005), and less availabilicy of health care services (WHO 2009a).
Many study designs have been used to examine the effects of temperature on mortality, including descriptive (Reid et al. 2009), case-control (Naughton et al. 2002), case-only (Schwartz 2005), case-crossover (Smargiassi et al. …