A time series study on the effects of heat on mortality and evaluation of heterogeneity into European and Eastern-Southern Mediterranean cities: results of EU CIRCE project

Abstract

BackgroundThe Mediterranean region is particularly vulnerable to the effect of summer temperature.Within the CIRCE project this time-series study aims to quantify for the first time the effect of summer temperature in Eastern-Southern Mediterranean cities and compared it with European cities around the Mediterranean basin, evaluating city characteristics that explain between-city heterogeneity.MethodsThe city-specific effect of maximum apparent temperature (Tappmax) was assessed by Generalized Estimation Equations, assuming a linear threshold model. Then, city-specific estimates were included in a random effect meta-regression analysis to investigate the effect modification by several city characteristics.ResultsHeterogeneity in the temperature-mortality relationship was observed among cities. Thresholds recorded higher values in the warmest cities of Tunis (35.5°C) and Tel-Aviv (32.8°C) while the effect of Tappmax above threshold was greater in the European cities. In Eastern-Southern Mediterranean cities a higher effect was observed among younger age groups (0–14 in Tunis and 15–64 in Tel-Aviv and Istanbul) in contrast with the European cities where the elderly population was more vulnerable. Climate conditions explained most of the observed heterogeneity and among socio-demographic and economic characteristics only health expenditure and unemployment rate were identified as effect modifiers.ConclusionsThe high vulnerability observed in the young populations in Eastern-Southern Mediterranean cities represent a major public health problem. Considering the large political and economic changes occurring in this region as well future temperature increase due to climate change, it is important to strengthen research and public health efforts in these Mediterranean countries.

The Health Effects of Climate Change in the WHO European Region

“…A greater increase in mortality on heatwave days was observed in Mediterranean cities compared with cities in northern parts of Europe (21.8% and 12.4% mortality increase, respectively) [15]. In contrast, cities with cooler climates have a greater increase in mortality per 1 °C increase above a local temperature threshold, compared to warmer cities [18]. A study in Central Italy found that a 1 °C increase in temperature above a threshold was associated with an increase in mortality of up to 15.97% among people aged 75 years or more, over a lag period of 30 days [19].…”

“…However, temperature-dependent mortality is also high among young populations, particularly in Eastern and Southern Mediterranean cities including Istanbul and Tel Aviv [18]. Increased summer temperatures also have consequences for pregnancy and preterm birth.…”

“…Extreme temperatures are associated with increases in mortality [15][16][17]22,32] Mortality increases are associated with temperatures above a local comfort threshold [13,18] Observed morbidity Extreme temperature is associated with increases in morbidity [20,23,26] Morbidity indicators are associated with higher temperatures [24,25,33] Future projection Future expected extreme temperatures are expected to increase heat-related mortality [14] Future increases in temperature are estimated to increase health effects of temperatures above a comfort temperature [28,29,31,34] Projected effects of heatwaves and high temperature have economic costs [27,30] Other or multiple focus There is confounding by air pollution for heat and cold effects [35] Heat and cold, mortality and morbidity, observation and projection are relevant in Europe [19] Different population subgroups are at risk [36] 3.1.2. Low Temperature and Cold Spells Ten papers identified in this search addressed the health effects of low temperatures and cold spells.…”

Impact of heat and cold waves on circulatory-cause and respiratory-cause mortality in Spain: 1975–2008

“…Traditionally, the impact of thermal extremes on mortality has been analysed from two different standpoints. While some studies have targeted the effects had by heat on morbidity and mortality (Leone et al 2013;Baccini et al 2013;Montero et al 2012;D'Ippoliti et al 2010;Basu 2009;Linares and Díaz 2008;Kovats and Ebi 2006;Díaz et al 2002), others -albeit less numerous-have targeted the effects had by cold waves on health (Montero et al 2010a;Díaz et al 2005;Donaldson and Rintamäki 2001;The Eurowinter Group 1997). However, few studies have compared the differentiated behaviour patterns of the respective extremes on mortality in a given population in the same region over the same period of time (Zanobetti et al 2013;Hajat et al 2007;Medina-Ramón et al 2006;Braga et al 2002;Huynen et al 2001).…”

Weather and climate versus mortality in Lisbon (Portugal) since the 19th century

“…Several studies have shown that temperature is one of the main climatic factors that influence mortality (Anderson & Bell, 2009;Basu, 2009;D'Ippoliti et al, 2010;Guirguis, Gershunov, Tardy, & Basu, 2014;Hajat & Kosatky, 2010;Leone et al, 2013); therefore, ManneKendall tests (Kendall, 1975;Mann, 1945) were applied to the temperature series of Lisbon's meteorological station (IDL, 1856e2012, Table 2, Fig. 1) in order to determine the presence of a trend (Rau, 2007;Sousa, García-Barr on, & Jurado, 2007).…”