Abstracts: ISEE 21st Annual Conference, Dublin, Ireland, August 25-29, 2009: Symposium Abstracts: Symposia Presentations
High ambient summer temperatures have been shown to influence daily mortality in cities across Europe. Quantification of the population mortality burden attributable to heat is crucial to the development of adaptive approaches. We quantified the impact of summer heat on mortality in 15 European cities during the 1990s. Projections of future impact of heat on mortality are also derived, on the basis of the climate changes scenarios reported in the Intergovernmental Panel on Climate Change Special Report on Emission Scenarios (IPCC, 2007). Three warming scenarios have been defined at 2030 on the basis of different hypothesis on future levels of greenhouse gas emission.
Materials and Methods:
We used a Monte Carlo approach to estimate the number of deaths attributable to heat for each city. These estimates rely on the results of a Bayesian random effects meta-analysis which combines city-specific heat-mortality functions as described by an exposure threshold corresponding to the minimum risk of death and a slope above the threshold.
The number of heat-attributable deaths per summer ranged from 0 in Dublin to 423 in Paris. The mean attributable fraction of deaths over the 15 cities was around 2%. The highest observed impact was in three Mediterranean cities (Barcelona, Rome and Valencia) and in two continental cities (Paris and Budapest). The largest impact was on persons over 75 years, but in some cities important proportions of heat-attributable deaths were also found for younger adults. Increases larger than 10% in the number of heat-attributable deaths at 2030 were found for most cities under the three IPCC scenarios.
Heat has an important impact on population mortality. Under warming hypotheses, this phenomenon is expected to increase. Attention should be given to the excess of deaths in younger cohorts, because it translates into larger numbers of potential years of life lost.