The impact of heat waves on mortality in 9 European cities: results from the EuroHEAT project

Abstract

BackgroundThe present study aimed at developing a standardized heat wave definition to estimate and compare the impact on mortality by gender, age and death causes in Europe during summers 1990-2004 and 2003, separately, accounting for heat wave duration and intensity.MethodsHeat waves were defined considering both maximum apparent temperature and minimum temperature and classified by intensity, duration and timing during summer. The effect was estimated as percent increase in daily mortality during heat wave days compared to non heat wave days in people over 65 years. City specific and pooled estimates by gender, age and cause of death were calculated.ResultsThe effect of heat waves showed great geographical heterogeneity among cities. Considering all years, except 2003, the increase in mortality during heat wave days ranged from + 7.6% in Munich to + 33.6% in Milan. The increase was up to 3-times greater during episodes of long duration and high intensity. Pooled results showed a greater impact in Mediterranean (+ 21.8% for total mortality) than in North Continental (+ 12.4%) cities. The highest effect was observed for respiratory diseases and among women aged 75-84 years. In 2003 the highest impact was observed in cities where heat wave episode was characterized by unusual meteorological conditions.ConclusionsClimate change scenarios indicate that extreme events are expected to increase in the future even in regions where heat waves are not frequent. Considering our results prevention programs should specifically target the elderly, women and those suffering from chronic respiratory disorders, thus reducing the impact on mortality.

Exploring the effects of high temperature on mortality in four cities in the Philippines using various heat wave definitions in different mortality subgroups

“…High temperature may deteriorate those people suffering from chronic pulmonary diseases, thereby pre-disposing them to greater risks [11]. Michelozzi et al [12] also note similar findings, whereby extreme temperatures may exacerbate chronic pulmonary diseases due to excess heat dissipation through circulatory adjustment.…”

“…In this study, since there is no standard definition for heat waves, we used the 2-, 4-, and 7-day duration with different intensities (90th, 95th, 97th, 98th, and 99th) as candidate HW definitions, which were also based on previous studies [9–11,13,18,23]. The selected intensities were city-specific, restricted to the dry season, which starts from December and ends in May.…”

“…These extreme temperatures account for greater risks, and to a certain extent, when analyzed separately, in relation to duration and intensity, which are the length of day and threshold temperature, respectively, constitute the notion of heat waves (HW) [6–10]. However, there is yet to be a unifying notion of standardizing HW definitions as these vary with respect to duration and intensity of temperature in a specific geographical area [11,12]. Nevertheless, various studies have similar observations of increasing risks with increasing duration and intensity, particularly on HW days [9–11,13,14].…”

“…However, there is yet to be a unifying notion of standardizing HW definitions as these vary with respect to duration and intensity of temperature in a specific geographical area [11,12]. Nevertheless, various studies have similar observations of increasing risks with increasing duration and intensity, particularly on HW days [9–11,13,14]. Major heat wave events have been recorded in the past years, such as the 1995 Chicago heat wave event, which claimed more than 600 excess deaths [15] and, in the summer of 2003, more than 70,000 excess deaths were recorded in Europe, which was partially attributed to the HW days [16].…”

Exceptionally Hot and Cold Summers in Europe (1951-2010)

“…In view of the unfavourable biometeorological conditions, as well as droughts and wildfires, during such periods this field of research has great merit. Indeed, sustained heat stress has an exceptionally adverse influence on human health and well-being and has been demonstrated to lead to higher mortality rates (BáaĪejczyk and Mc Gregor 2007, Hutter et al 2007, D'Ippoliti et al 2010, Twardosz 2009, Muthers et al 2010, Barriopedro et al 2011, Zvyagintsev et al 2011, Revich and Shaposhnikov 2012. Droughts tend to cause losses in agriculture and contribute to forest fires, sometimes over large areas, such as in the summers of 2003 and 2010 (Hodzic et al 2007, Zvyagintsev et al 2011.…”