The Mortality and Morbidity Risk due to Heat Waves

Question: What is the risk of morbidity and mortality in the City of Perth due to Heat Waves? Answer: Introduction The combined effects of climate change, rising global temperatures and urbanization have all contributed to an increase in the number of warm nights as well as more regular and longer heat wave durations. As a consequence, the impact that climate change on Australias populations health has gained increased concerns ('Center for Climate and Energy Solutions', 2017). In recent times, populations have suffered serious health, social, and economic effects in Europe, south East Australia, and the USA, especially in urban areas. This is because urban areas have the issue of buildings that affect the natural micro environment and can act as heat traps during a heat wave. Such events have a multiplier effect, impacting emergency response systems, management of health risk, and infrastructure such as power supply systems (Russo, Sillmann, Fischer, 2015), (Lemonsu, Vigui, Daniel, Masson, 2015). It is widely known that exposure to extreme temperatures significantly impact human health, and in extreme cases, may result in fatality. An example is when over 70 thousand deaths were attributed to the heat wave of 2003 across Europe. Research shows that the relationship between mortality and temperature is usually not linear; further, the highest mortality is usually not achieved on the same day when peak temperatures are reached. This paper discusses the risk of morbidity and mortality in the City of Perth, Australia, by formulating a research question and then providing an answer, basing the discussion on geospatial data for the City of Perth, Australia obtained from AURIN combined with other sources such as the ABS. Risk of morbidity and mortalit The City of Perth is located within the greater Perth metropolitan area; the Perth Metropolitan Area is the capital of the Western Australia. The City of Perth is located on latitude 31.951o S and Longitude 115.818o East with an elevation of 42 meters. Australia has suffered more heat wave deaths than all other natural causes combined and with the effects of climate change, the duration, frequency, and intensity of heat waves are expected to increase. Apart from causing heat stroke and heat exhaustion, exposure to heat can also exacerbate preexisting medical conditions such as high blood pressure and diabetes. Different people also have different vulnerabilities to heat exposure, with older adults (above 65), outdoor laborers, children, geographically isolated persons, different races and ethnicities( especially those having low Socio Economic Status) are at an increased risk. The impact of heat and heat waves is likely to be multiplied due to amplification of existing risks relating to heat exposure, including buildings and the materials used for the buildings. Buildings, despite being designed to provide shelter, are associated with other hazards such as extreme temperatures and poor air. The density of urban areas has an impact on heat wave effects; high densities coupled with a high urban heat island (UHI) will increase the heat load urban populations experience. During adverse weather conditions, people are more likely to spend most times indoors and research shows that multi dwelling structures are more vulnerable to higher mortality rates during heat waves, using data from the 2003 heat wave in France (Erdman, 2015). Research also shows that urban areas have a higher risk of death than rural areas during heat waves (Gabriel, Endlicher, 2011). The image below shows the aerial view of the city of Perth showing the urban areas and the green (tree) cover for the City; Source: AURIN The City of Perth has a population of 21 092 (for the municipality) spread around the suburbs of Perth, Crawley, East Perth, West Perth, Nedlands, Northbridge, and Subiaco. Source; ABS The factors that are likely to impact mortality and morbidity due to extreme temperatures (hot ) are summarized in the table below, Number Factor 1 Age 2 Accessibility/ remoteness 3 Socio economic index 4 Gender Past studies have shown that the older the person, the greater the impact and effects of heat and heat waves; a 10 oC increase in the maximum temperatures was associated with a 9.8% increase in daily mortality rates (Williams et al., 2012) . The figure below shows historical data showing the relationship between heat and the factors (variables) that affect the effects of heat waves Below is a heat map of Australia taking an average of ten years from 2006; it shows that Perth and Western Australia has on average experienced the highest rise in average temperatures, which makes the region of Perth City a highly risky area during a heat wave. During heat waves, a number of facilities are affected, including power supply systems that in turn interfere with air conditioning services, creating heat traps. The use of glass and having multi story buildings further exacerbate the problem as urban heat islands are created and the buildings act as heat traps. The risk index for morbidity and mortality for the city of Perth therefore is highest in the high density building areas around central Perth and where there are multiple story buildings as the below heat map indicates, the darker the color, the greater the risk of morbidity or mortality from a heat wave in the City of Perth. As the images above show, planers and emergency personnel should develop emergency systems as well as other ways of mitigating the effects of heat waves by concentrating on areas with a higher density of multi-story buildings which act as heat traps, have the lowest tree canopy cover, and experience elevated temperatures that exceed the 30 oC threshold for continued periods. Central Perth City has glass sided tall skyscrapers that rely on air conditioning to keep people inside cool; however, these can become huge heat traps; if there was power failure due to a heat wave; for instance, the buildings will become heat traps and can cause mortality and other adverse health effects, apart from being extremely uncomfortable. The heat map shows that the central regions of Melbourne experience greater warmth, making them UHIs and this is mainly because of human activity of tall buildings made of glass. Glass also reflects away some heat to surrounding buildings; these exacerbate the heat wav es as they create heat traps References 'Australian Bureau of Statistics',. (2017). Regional Population Growth, Australia, 2012-13. Abs.gov.au. Retrieved 3 April 2017, from https://www.abs.gov.au/ausstats/abs@.nsf/products/AC53A071B4B231A6CA257CAE000ECCE5?OpenDocument 'Center for CLimate and Energy Solutions',. (2017). Extreme Heat and Climate Change | Center forClimate and Energy Solutions. C2es.org. Retrieved 3 April 2017, from https://www.c2es.org/science-impacts/extreme-weather/extreme-heat Erdman, J. (2015). Heat Records Shattered in Germany, France, The Netherlands in June/July 2015 Europe Heat Wave. The Weather Channel. Retrieved 3 April 2017, from https://weather.com/forecast/news/europe-heat-wave-record-highs-june-july-2015 Gabriel, K., Endlicher, W. (2011). Urban and rural mortality rates during heat waves in Berlin and Brandenburg, Germany. Environmental Pollution, 159(8-9), 2044-2050. https://dx.doi.org/10.1016/j.envpol.2011.01.016 Lemonsu, A., Vigui, V., Daniel, M., Masson, V. (2015). Vulnerability to heat waves: Impact of urban expansion scenarios on urban heat island and heat stress in Paris (France). Urban Climate, 14, 586-605. https://dx.doi.org/10.1016/j.uclim.2015.10.007 Russo, S., Sillmann, J., Fischer, E. (2015). Top ten European heatwaves since 1950 and their occurrence in the coming decades. IOP. Retrieved 3 April 2017, from https://iopscience.iop.org/article/10.1088/1748-9326/10/12/124003/meta Williams, S., Nitschke, M., Weinstein, P., Pisaniello, D., Parton, K. and Bi, P. (2012). The impact of summer temperatures and heatwaves on mortality and morbidity in Perth, Australia 19942008. Environment International, [online] 40, pp.33-38. Available at: https://www.researchgate.net/publication/221780781_The_impact_of_summer_temperatures_and_heatwaves_on_mortality_and_morbidity_in_Perth_Australia_1994-2008.