Suchergebnisse

Abstract. Trends of extreme-temperature episodes in cities are
increasing (in frequency, magnitude and duration) due to regional climate
change in interaction with urban effects. Urban morphologies and thermal
properties of the materials used to build them are factors that influence spatial and temporal climate variability and are one of the main
reasons for the climatic singularity of cities. This paper presents a
methodology to evaluate the urban and peri-urban effect on extreme-temperature exposure in Barcelona (Spain), using the Local Climate Zone
(LCZ) classification as a basis, which allows a comparison with
other cities of the world characterised using this criterion. LCZs were
introduced as input of the high-resolution UrbClim model (100 m spatial
resolution) to create daily temperature (median and maximum) series for
summer (JJA) during the period 1987 to 2016, pixel by pixel, in order to
create a cartography of extremes. Using the relationship between mortality
due to high temperatures and temperature distribution, the heat exposure
of each LCZ was obtained. Methodological results of the paper show the
improvement obtained when LCZs were mapped through a combination of two
techniques (land cover–land use maps and the World Urban Database and Access Portal Tools – WUDAPT – method), and the paper proposes a methodology to obtain the exposure to high temperatures of
different LCZs in urban and peri-urban areas. In the case of Barcelona, the
distribution of temperatures for the 90th percentile (about
3–4 ∘C above the average conditions) leads to an increase in
the relative risk of mortality of 80 %.

Numerous studies have demonstrated the relationship between summer temperatures and increased heat-related deaths. Epidemiological analyses of the health effects of climate exposures usually rely on observations from the nearest weather station to assess exposure-response associations for geographically diverse populations. Urban climate models provide high-resolution spatial data that may potentially improve exposure estimates, but to date, they have not been extensively applied in epidemiological research. We investigated temperature-mortality relationships in the city of Barcelona, and whether estimates vary among districts. We considered georeferenced individual (natural) mortality data during the summer months (June-September) for the period 1992-2015. We extracted daily summer mean temperatures from a 100-m resolution simulation of the urban climate model (UrbClim). Summer hot days (above percentile 70) and reference (below percentile 30) temperatures were compared by using a conditional logistic regression model in a case crossover study design applied to all districts of Barcelona. Relative Risks (RR), and 95% Confidence Intervals (CI), of all-cause (natural) mortality and summer temperature were calculated for several population subgroups (age, sex and education level by districts). Hot days were associated with an increased risk of death (RR = 1.13; 95% CI = 1.10-1.16) and were significant in all population subgroups compared to the non-hot days. The risk ratio was higher among women (RR = 1.16; 95% CI= 1.12-1.21) and the elderly (RR = 1.18; 95% CI = 1.13-1.22). Individuals with primary education had similar risk (RR = 1.13; 95% CI = 1.08-1.18) than those without education (RR = 1.10; 95% CI= 1.05-1.15). Moreover, 6 out of 10 districts showed statistically significant associations, varying the risk ratio between 1.12 (95% CI = 1.03-1.21) in Sants-Montjuïc and 1.25 (95% CI = 1.14-1.38) in Sant Andreu. Findings identified vulnerable districts and suggested new insights to public health policy makers on how to develop district-specific strategies to reduce risks. ; J.B. gratefully acknowledges funding from the European Union's Horizon 2020 research and innovation programme under grant agreements No 865564 (European Research Council Consolidator Grant EARLY-ADAPT), 727852 (project Blue-Action) and 730004 (project PUCS), and from the Ministry of Science and Innovation (MCIU) under grant agreements No RYC2018-025446-I (programme Ramón y Cajal) and EUR2019-103822 (project EURO-ADAPT). V.I. acknowledges funding from the European Union's Horizon 2020 research and innovation programme under grant agreements 730004 (project PUCS). H.A. gratefully acknowledges funding from the Secretariat for Universities and Research of the Ministry of Business and Knowledge of the Government of Catalonia (grant numbers B00391 [FI-2018], B100180 [FI-2019] and B200139 [FI-2020]).

Background: Car-dependent city planning has resulted in high levels of environmental pollution, sedentary lifestyles and increased vulnerability to the effects of climate change. The Barcelona Superblock model is an innovative urban and transport planning strategy that aims to reclaim public space for people, reduce motorized transport, promote sustainable mobility and active lifestyles, provide urban greening and mitigate effects of climate change. We estimated the health impacts of implementing this urban model across Barcelona. Methods: We carried out a quantitative health impact assessment (HIA) study for Barcelona residents ≥20 years (N = 1,301,827) on the projected Superblock area level (N = 503), following the comparative risk assessment methodology. We 1) estimated expected changes in (a) transport-related physical activity (PA), (b) air pollution (NO2), (c) road traffic noise, (d) green space, and (e) reduction of the urban heat island (UHI) effect through heat reductions; 2) scaled available risk estimates; and 3) calculated attributable health impact fractions. Estimated endpoints were preventable premature mortality, changes in life expectancy and economic impacts. Results: We estimated that 667 premature deaths (95% CI: 235-1,098) could be prevented annually through implementing the 503 Superblocks. The greatest number of preventable deaths could be attributed to reductions in NO2 (291, 95% PI: 0-838), followed by noise (163, 95% CI: 83-246), heat (117, 95% CI: 101-137), and green space development (60, 95% CI: 0-119). Increased PA for an estimated 65,000 persons shifting car/motorcycle trips to public and active transport resulted in 36 preventable deaths (95% CI: 26-50). The Superblocks were estimated to result in an average increase in life expectancy for the Barcelona adult population of almost 200 days (95% CI: 99-297), and result in an annual economic impact of 1.7 billion EUR (95% CI: 0.6-2.8). Discussion: The Barcelona Superblocks were estimated to help reduce harmful environmental exposures (i.e. air pollution, noise, and heat) while simultaneously increase PA levels and access to green space, and thereby provide substantial health benefits. For an equitable distribution of health benefits, the Superblocks should be implemented consistently across the entire city. Similar health benefits are expected for other cities that face similar challenges of environmental pollution, climate change vulnerability and low PA levels, by adopting the Barcelona Superblock model. ; We would like to thank Maria Foraster for helpful advice on the noise analyses and Glòria Carrasco for taking the pictures of the Sant Antoni Superblock. JB gratefully acknowledges funding from the European Union's Horizon 2020 research and innovation programme under grant agreements No 727852 (project Blue-Action), 730004 (project PUCS) and 737480 (Marie Sklodowska-Curie fellowship ACCLIM). The climate-fit. city is developed as part of the PUCS project, which has received funding from the European Union's H2020 Research and Innovation Programme under Grant Agreement No. 73004.