Research
The impact of heat waves on mortality in 9 European cities: results from the EuroHEAT project
1 Department of Epidemiology, Regional Health Authority, Rome, Italy
2 WHO Regional Office for Europe, Rome, Italy
3 Department of Hygiene and Epidemiology, Medical School, University of Athens, Greece
4 Centre for Research in Environmental Epidemiology, Barcelona, Catalonia, Spain
5 National Institute of Environmental Health, Budapest, Hungary
6 Division of Community Health Sciences, St. George's University, London, UK
7 Public and Environmental Health Research Unit, London School of Hygiene and Tropical Medicine, London, UK
8 Department of Epidemiology, Health Authority Milan, Milan, Italy
9 Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Epidemiology, Neuherberg, Germany
10 Department of Environmental Health, French Institute for Public Health Surveillance, Saint Maurice, Cedex France
11 Epidemiology and Statistics Unit, Valencian School of Health Studies, Valencia, Spain
Environmental Health 2010, 9:37 doi:10.1186/1476-069X-9-37
Published: 16 July 2010Abstract
Background
The 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.
Methods
Heat 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.
Results
The 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.
Conclusions
Climate 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.



