Heat Wave and Elderly Mortality: Historical Analysis and Future Projection for Metropolitan Region of São Paulo, Brazil

Abstract

The Metropolitan Region of Sao Paulo (MRSP) is one of the main regions of Brazil that in recent years has shown an increase in the number of days with heat waves, mainly affecting the health of the most sensitive populations, such as the elderly. In this study, we identified the heat waves in the MRSP using three different definitions regarding the maximum daily temperature threshold. To analyze the impact of heat waves on elderly mortality, we used distributed lag nonlinear models (dlnm) and we quantified the heat wave-related excess mortality of elderly people from 1985 to 2005 and made projections for the near future (2030 to 2050) and the distant future (2079–2099) under the climate change scenarios RCP4.5 and RCP8.5 (RCP: Representative Concentration Paths). An important aspect of this research is that for the projections we take into account two assumptions: non-adaptation and adaptation to the future climate. Our projections show that the heat wave-related excess of elderly mortality will increase in the future, being highest when we consider no adaptation, mainly from cardiovascular diseases in women (up to 587 deaths per 100,000 inhabitants per year). This study can be used for public policies to implement preventive and adaptive measures in the MRSP.

Climate change research and action must look beyond 2100

“…Heat stress can be fatal to humans when wet-bulb temperatures exceed 35°C for 6 or more hours (Buzan & Huber, 2020;Sherwood & Huber, 2010). Physiologically fit humans can tolerate higher dry-air temperatures, but such temperatures can still lead to high mortalities (Diniz et al, 2020;Varghese et al, 2020). These conditions also cause damage to critical infrastructure on which humans rely, such as electricity (Burillo et al, 2019), transportation (Villalba Sanchis et al, 2020, and agriculture (Anderson et al, 2020;Mehrabi, 2020).…”

Excess Risk of Mortality Due to Heatwaves in Dezful city, Southwest of Iran

“…In this regard, Linares (2015) stated that, in Spain increasing each Celsius degree of daily maximum temperature from the threshold of 37 °C could increase the risk of mortality by 10.3 % [39]. Also, similar results were found in studies conducted in Brazil [40] and India [14,27]. In these studies, which examined the effect of heatwaves on the mortality of four cities with high average temperatures, Nouri Sarma (2019) and Azhar (2014) found that the risk of death on days with heatwaves has increased signi cantly [14,27].…”

The influence of soil dry-out on the record-breaking hot 2013/2014 summer in Southeast Brazil

“…During the outstanding 2013/2014 summer season, SEB experienced a historical unprecedented heatwave. It was the longest and most severe summer heatwave episode ever recorded over both the UASP and UACT for the past four decades, and was responsible for an increase in the numbers of heat-related mortality 38 , 44 . The obtained high HWMId values for this season revealed the exceptional magnitude of this particular event that occurred during a record-breaking summer season, which finds parallel in its magnitude and extent with the remarkable 2003 European and 2010 Russian summers 2 , 45 , 46 .…”

“…Moreover, they would represent a guideline for predicting future episodes of this kind and mitigate the associated natural, socio-economic and public health impacts for Brazil. The increased heat-related impact observed during the 2013/2014 summer 38 , 44 should encourage political, health and civil protection authorities to seek tools and mitigation measures to improve the control of illnesses related to hot periods, particularly in megacities in developing countries like Brazil 33 , 47 . Finally, robust projections indicate a future climate scenario controlled by hotter and drier conditions in South America and specifically in Brazil 39 – 41 and consequently, by an increasing frequency of more intense and longer lasting CDH episodes.…”