Evaluating the impact of extreme temperature based indices in the 2003 heatwave excessive mortality in Portugal

Thumbnail Image
Full text at PDC
Publication Date
Advisors (or tutors)
Journal Title
Journal ISSN
Volume Title
Elsevier Science Ltd
Google Scholar
Research Projects
Organizational Units
Journal Issue
This paper analyses the impact of the 2003 European heatwave on excessive human mortality in Portugal, a country that presents a relatively high level of exposure to heatwave events. A total of 2399 excessive deaths are estimated in continental Portugal, which implies an increase of 58% over the expected deaths. When these values are split by gender, it is seen that women increase (79%), was considerably higher than that recorded for men (41%). The increment of mortality due to this heatwave was detected for all the 18 districts of the country, but its magnitude was significantly higher in the inner districts close to the Spanish border. When we split by gender all districts reveal significant mortality increments for women, while the impact in men’s excess deaths is not significant over 3 districts. Several temperature derived indices were used and evaluated in their capacity to explain, at the regional level, the excessive mortality (ratio between observed and expected deaths) by gender. It is shown that the best relationship is found for the total exceedance of extreme days, an index combining the length of the heatwave and its intensity. Both variables hold a linear relationship with r = 0.79 for women and a poorer adjustment (r = 0.50) for men. Additionally, availability of mortality data split by age also allowed obtaining detailed information on the structure of the population in risk, namely by showing that statistically significant increments are concentrated in the last three age classes (45–64, 65–74 and 75 or more). The use of air conditioning systems in some Portuguese hospitals had a major impact on the decrease (up to 40%) in excessive mortality values. A finer approach is relevant for prevention strategies, since it allows to identify better the target population of any preventive strategy regional and national authorities may be interested to implement.
© 2009 Elsevier Ltd. All rights reserved. This work was supported by the Gulbenkian Foundation through project IMPACTE (No. 1568). Ricardo Trigo and Ricardo García-Herrera received support from the Portuguese-Spanish integrated action (E-27/2005) funded by CRUP and MCYT and the EU 6th Framework Program (CIRCE) contract number 036961 (GOCE). Alexandre M. Ramos received a scholarship from the IMPACTE project.