Content uploaded by Agnès Lefranc
Author content
All content in this area was uploaded by Agnès Lefranc
Content may be subject to copyright.
A preview of the PDF is not available
The impact of heat waves on mortality in 9 European cities: Results from the EuroHEAT project
Abstract and Figures
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.
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.
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.
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.
Figures - uploaded by Agnès Lefranc
Author content
All figure content in this area was uploaded by Agnès Lefranc
Content may be subject to copyright.
... In Figure 9, where interaction effects are examined, the blue spots following red areas suggest harvesting, as vulnerable individuals are hospitalized early or succumb quickly, leading to a temporary decline in admissions. Similarly, in Figure 3 (DMAQIL contour plot), a sharp RR increase was observed at lag 0, as the DMAQIL surpasses 6, followed by a part of a blue spot, which aligns with previous studies identifying mortality displacement after acute exposure peaks [95,96]. ...
The aim of this study is to examine the impact of poor air quality and adverse meteorological conditions on health risks in the Greater Athens Area (GAA), Greece, during the period from 2018 to 2022. Specifically, the aim is to assess the Relative Risk (RR) of hospital admissions (HAs) for cardiovascular diseases (CVDs) and respiratory diseases (RDs), due to air pollution in combination with thermal discomfort, as well as to identify the time lag effect on admissions. For this purpose, data from six (6) different hospitals within the GAA were collected and used. Statistical analysis of hourly measurements of key pollutants (NO2, O3, PM2.5, and PM10) obtained from the Directorate of Climate Change and Air Quality (DCCAQ), which falls under the auspices of the Ministry of Environment and Energy (MEE), and meteorological parameters (T, RH, and wind velocity), is performed to calculate the daily air quality and human thermal comfort–discomfort levels, respectively. These conditions were examined using appropriate indexes for both air quality and human thermal comfort–discomfort, as independent variables in a Negative Binomial regression model developed in R, with daily HAs (not including scheduled cases or pre-existing health conditions) as the response variable. Moreover, a spatiotemporal analysis of air quality and meteorological parameters is conducted to identify associated variations in health risks. This analysis highlights key risk patterns linked to environmental conditions and the relevant measures to both manage and mitigate the risk. Findings indicate that extreme environmental conditions significantly elevate health risks, with cumulative RR over a one-week period peaking at 1.540 (95% CI: 1.158–2.050) during the warm season, while prolonged increases in the RR are also observed during the cold season, reaching 1.214 (95% CI: 0.937–1.572) under extreme cold exposures.
... The Mediterranean region stands out most for its warming (Giorgi 2006;Fischer and Schär 2009;Jacob et al. 2014, Vicedo-Cabera et al. 2018Zittis et al. 2019;Vogel et al. 2020;Cos et al. 2022;Feng et al. 2022;Oliveira et al. 2022, Urdiales-Flores et al. 2023, which is expected to exceed global rates by 20% (50% in summer) during this century (Lionello and Scarascia 2018), further accentuating its already known vulnerability (Diffenbaugh et al. 2007;Baccini et al. 2008;D'Ippoliti et al. 2010;Kendrovski et al. 2017;Spinoni et al. 2018;MedECC 2020). ...
In the current context of global warming, heat waves are extreme climate events that have captured the focused attention of the scientific community due to their increasing impact on public health, energy consumption, fire risk, and agriculture livestock. Although less studied, cold waves remain an extreme climate event to be reckoned with, with implications for transport systems, energy consumption, crops, and human health. This paper presents an analysis of the representative concentration pathway (RCP) 4.5 and RCP 8.5 scenarios under European Coordinated Regional Downscaling Experiment simulations using the excess heat factor (EHF) and excess cold factor indices for the Iberian Peninsula and the Balearic Islands (IPB). The study period is the second half of the 21st Century (2050–2095) with respect to the historical reference period (1971–2000), and the dimensions analysed are intensity and spatial extent. The projected EHF results show a very significant increase on these dimensions. The average change in maximum heat wave intensity for the IPB is projected to be 144%, which is 40% more than in the 2021–2050 period. The largest changes are expected in the east and southeast and will reach 300%. The average spatial extent of heat waves is projected to increase by 1–2.7% per decade, significantly amplifying fire risk, energy demand, and human exposure. For cold waves, both dimensions will decrease. The average change in maximum cold wave intensity will be − 16%, and the maximum extent will decrease much more than the average, with decreases between − 0.7%/decade and − 3.2%/decade, which will imply lower exposure. Despite this, the RCP 8.5 scenario will record a higher maximum intensity of cold waves in the IPB than the RCP 4.5 scenario, demonstrating that such events will continue to exist in the second half of the century, even with high radiative forcing.
Atmospheric heat waves are expected to be more severe, frequent and persistent in the decades to come. Here, we sought to ascertain to what extent such a worsened scenario of this adverse phenomenon may be affected by a projected slowdown of the Atlantic Meridional Overturning Circulation (AMOC), thus accounting for an important gap in our knowledge of physical mechanisms related to heat waves – the role of large-scale climate variability pertaining to ocean circulation impacts. We conducted a comparison between two CCSM4 simulations (nominal forcings vs. a parallel sensitivity experiment that keeps the AMOC strength constant). Our findings reveal that a hampered northward heat transport due to the AMOC weakening causes robust, widespread and significant cooling in the Northern Hemisphere and parts of South America relative to the control simulation, whereas most of the Southern Hemisphere displays a warming signal, but in a much milder amplitude and typically lacking significance over land masses. Therefore, notwithstanding other potentially noxious effects of an abated AMOC on the climate system, it should act mostly as an attenuating factor in this regard, as future heat waves will generally not be as intense as they could be under a global warming scenario where the AMOC would keep its strength.
The global rise in temperatures contributes to the increase of climate-sensitive diseases. Despite mitigation efforts, temperatures are projected to keep rising, highlighting the need for integrated methods to assess the impact of thermal environments on human health. This study summarizes the existing evidence on the statistical relationships (associations) between thermal indices and health outcomes. Medline, Scopus, and Web of Science were systematically searched until December, 2023 for studies examining the association between thermal indices and health outcomes in outdoor environments (protocol registration: PROSPERO CRD42023412470). The quality of the included studies was assessed using the United States National Institutes of Health Quality Assessment Tool. The search identified 5038 records, with 310 meeting eligibility criteria and examining 1143 associations. These associations represented 51 countries, primarily in North America (n = 448, 39.2%) and Europe (n = 399, 34.9%). Temperate climates (n = 597, 52.2%) were the most frequently examined. Seventeen indices were identified, with Apparent Temperature being the most common (141 publications, 634 associations). Frequently used indices included also Heat Index, Universal Thermal Climate Index, and Physiologically Equivalent Temperature. About half of the associations focused on mortality and half on morbidity. The most frequently examined associations were for diseases of the circulatory system (n = 304, 26.6%), all-cause morbidity/mortality (n = 288, 25.2%), and diseases of the respiratory system (n = 151, 13.2%). Among associations examining heat-related outcomes (n = 882), 57.8% (n = 510) suggested an increased risk of adverse health outcomes as indices increased, while for cold-related outcomes (n = 367), 44.1% (n = 162) suggested an increased risk as indices decreased. This systematic review reveals significant associations between thermal indices and health outcomes, indicating that thermal indices could be valuable tools for public health planning. However, the diversity in methodologies across studies highlights the need for standardization in methodology and reporting, including the reporting of non-significant findings.
The increase in life expectancy is generally associated with greater lifespan equality, but this is not always true, especially among the elderly, as seen in the case we are examining. This is what we show in this research through the reconstruction of a series of life tables for the oldest-old from the cohorts born between 1890 and 1919, starting from age 85. To date, only the 1890–1911 cohorts can be considered extinct, so the study of the sex-based mortality gap focuses on these cohorts, while all cohorts are considered in the study of age-at-death disparities. Both absolute and relative standard statistical measures were used as indicators, highlighting inconsistencies between absolute and relative measures in this final section of cohort life tables. Our findings reveal an evolution of mortality characterized by cohort effects, especially among older cohorts and to an overall decline in the mortality occurring in the context of two different ageing patterns for the two sexes. The outcomes not only show an increasing mortality male excess in, but also significant disparities in the average inter-individual differences in lifespan.
This study provides an overview and comparative analysis of sustainable urban mitigation strategies to address heat-related mortalities and thermal discomfort. Employing a comprehensive literature review and quantitative analysis, it evaluates various interventions—including green infrastructure, building materials, urban morphology, and technological innovations—alongside their impacts on mortality rates. A novel methodology is proposed for assessing the relationship between urban design factors and heat stress-related health outcomes, with attention to vulnerable populations. Key findings reveal that each 0.1 increase in normalized difference vegetation index (NDVI) reduces heat-related mortality by 6–10% in low-GDP regions, while medical strategies such as warning systems and cooling centers lower mortality by 10–30%. However, emerging technologies like PV panels and AAHPs show localized temperature increases of up to 0.9℃. This paper highlights the critical role of balanced urban strategies to mitigate adverse effects of climate change, offering practical insights for policymakers, urban planners, and public health officials seeking sustainable solutions.
We carried out time-series analyses in 12 U.S. cities to estimate both the acute effects and the tagged influence of weather on respiratory and cardiovascular disease (CVD) deaths. We fit generalized additive Poisson regressions for each city using nonparametric smooth functions to control for long time trend, season, and barometric pressure. We also controlled for day of the week. We estimated the effect and the lag structure of both temperature and humidity based on a distributed lag model. In cold cities, both high and low temperatures were associated with increased CVD deaths. In general, the effect of cold temperatures persisted for days, whereas the effect of high temperatures was restricted to the day of the death or the day before. For myocardial infarctions (MI), the effect of hot days was twice as large as the cold-day effect, whereas for all CVD deaths the hot-day effect was five times smaller than the cold-day effect. The effect of hot days included some harvesting, because we observed a deficit of deaths a few days later, which we did not observe for the cold-day effect. In hot cities, neither hot nor cold temperatures had much effect on CVD or pneumonia deaths. However, for MI and chronic obstructive pulmonary disease deaths, we observed lagged effects of hot temperatures (lags 4-6 and lags 3 and 4, respectively). We saw no clear pattern for the effect of humidity. In hierarchical models, greater variance of summer and winter temperature was associated with larger effects for hot and cold days, respectively, on respiratory deaths.
A relative climatological index is developed to evaluate interregional
variations in human discomfort and the impacts of weather on a variety
of socioeconomic parameters. The "weather stress index" is designed to
assess the frequency and magnitude of the most uncomfortable weather
conditions, and data inputs are limited to air temperature, dewpoint,
and wind speed. The index is constructed by calculating the apparent
temperature using a simple algorithm and comparing how a particular
day's apparent temperature varies from the mean for that day at that
locale. The index ranges from 0 percent to 100 percent, with the most
uncomfortable apparent temperatures exhibiting the highest values.A
geographical distribution of July apparent temperatures at the 95
percent and 99 percent weather-stress-index level indicates that the
central and south central United States experience the highest apparent
temperatures in the nation. These conditions occur when the surface flow
permits maritime air to intrude while a 500-mb ridge is present to
encourage atmospheric subsidence. The combination of these events almost
never occurs in the Desert Southwest, and the highest apparent
temperatures here do not reach the levels encountered in the centres
United States.The use of the weather stress index should enhance
interregional evaluation and facilitate the development of large-scale
models for analyses of numerous climate-impact relationships.
The second edition of this best-selling book has been thoroughly revised and expanded to reflect the significant changes and advances made in systematic reviewing. New features include discussion on the rationale, meta-analyses of prognostic and diagnostic studies and software, and the use of systematic reviews in practice.
Background: Mortality increases with hot weather, although the extent to which lives are shortened is rarely quantified. We compare the extent to which short-term mortality displacement can explain heat deaths in Delhi, Sao Paulo, and London given contrasting demographic and health profiles. Methods: We examined time-series of daily mortality data in relation to daily ambient temperature using Poisson models and adjusting for season, relative humidity, rainfall, particulate air pollution, day of the week, and public holidays. We used unconstrained distributed lag models to identify the extent to which heat-related excesses were followed by deficits (mortality displacement). Results: For each city, an increase in all-cause mortality was observed with same-day (lag 0) and previous day (lag 1) temperatures greater than a threshold of 20 degrees C. At lag 0, the excess risk was greatest in Delhi and smallest in London. In Delhi, an excess was apparent up to 3 weeks after exposure, after which a deficit was observed that offset just part of the overall excess. In London, the heat excess persisted only 2 days and was followed by deficits, such that the sum of effects was 0 by day 11. The pattern in Sao Paulo was intermediate between these. The risk summed over the course of 28 days was 2.4% (95% confidence interval = 0.1 to 4.7%) per degree greater than the heat threshold in Delhi, 0.8% (- 0.4 to 2.1%) in Sao Paulo and -1.6% (-3.4 to 0.3%) in London. Excess risks were sustained up to 4 weeks for respiratory deaths in Sao Paulo and London and for children in Delhi. Conclusions: Heat-related short-term mortality displacement was high in London but less in Delhi, where infectious and childhood mortality still predominate.