Huge decrease of frost frequency in the Mont-Blanc Massif under climate change.

Mountains are a sensitive indicator of climate change and these areas are an early glimpse of what could happen in lowland environments. Peaking at 4808 m asl, the Mont-Blanc summit, at the boundary between France and Italy, is the highest of the Alps, in Western Europe. Its Massif is world-famous for outdoor and extreme sport activities, especially since the 1924 Olympic games held in Chamonix. Here, we use a novel statistical downscaling approach to regionalize current and future climate change over the Mont-Blanc Massif at an unequalled spatial resolution of 200 m. The algorithm is applied to daily minimum and maximum temperature derived from global climate models used in the fifth assessment report of the International Panel on Climate Change (IPCC). This new high-resolution database allows for a precise quantification of frost occurrence and its evolution until 2100. In the winter season and by the end of the 21st century, under a pessimistic scenario (RCP8.5), frost frequency in the morning could decrease by 30-35 percentage points in the valley of Chamonix, and in the afternoon, similar changes could occur for elevations comprised between 2000 and 3000 m. In summertime, changes are even larger, reaching a huge drop of 45-50 points in the afternoon between 3500 and 4500 m. These changes are much reduced under an optimistic scenario. They could have huge impacts on the environment (glacier shrinking, permafrost degradation, floods, changes in the distribution of species and ecosystems) and societies (summer tourism for climbing and hiking, and winter tourism for skiing).

Do outdoor environmental noise and atmospheric NO2 levels spatially overlap in urban areas?

The urban environment holds numerous emission sources for air and noise pollution, creating optimum conditions for environmental multi-exposure situations. Evaluation of the joint-exposure levels is the main obstacle for multi-exposure studies and one of the biggest challenges of the next decade. The present study aims to describe the noise/NO2 multi-exposure situations in the urban environment by exploring the possible discordant and concordant situations of both exposures. Fine-scale diffusion models were developed in the European medium-sized city of Besançon (France), and a classification method was used to evaluate the multi-exposure situations in the façade perimeter of 10,825 buildings. Although correlated (Pearson's r = 0.64, p < 0.01), urban spatial distributions of the noise and NO2 around buildings do not overlap, and 30% of the buildings were considered to be discordant in terms of the noise and NO2 exposure levels. This discrepancy is spatially structured and associated with variables describing the building's environment. Our results support the presence of several co-existing, multi-exposure situations across the city impacted by both the urban morphology and the emission and diffusion/propagation phases of each pollutant. Identifying the mechanisms of discrepancy and convergence of multi-exposure situations could help improve the health risk assessment and public health.

Modelling and mapping trace element accumulation in Sphagnum peatlands at the European scale using a geomatic model of pollutant emissions dispersion.

Trace elements (TEs) transported by atmospheric fluxes can negatively impact isolated ecosystems. Modelling based on moss-borne TE accumulation makes tracking TE deposition in remote areas without monitoring stations possible. Using a single moss species from ombrotrophic hummock peatlands reinforces estimate quality. This study used a validated geomatic model of particulate matter dispersion to identify the origin of Cd, Zn, Pb and Cu accumulated in Sphagnum capillifolium and the distance transported from their emission sources. The residential and industrial sectors of particulate matter emissions showed the highest correlations with the TEs accumulated in S. capillifolium (0.28(Zn)-0.56(Cu)) and (0.27(Zn)-0.47(Cu), respectively). Distances of dispersion varied depending on the sector of emissions and the considered TE. The greatest transportation distances for mean emissions values were found in the industrial (10.6 km when correlating with all TEs) and roads sectors (13 km when correlating with Pb). The residential sector showed the shortest distances (3.6 km when correlating with Cu, Cd, and Zn). The model presented here is a new tool for evaluating the efficacy of air pollution abatement policies in non-monitored areas and provides high-resolution (200 × 200 m) maps of TE accumulation that make it possible to survey the potential impacts of TEs on isolated ecosystems.

Air pollution in moderately polluted urban areas: How does the definition of "neighborhood" impact exposure assessment?

Environmental health studies commonly quantify subjects' pollution exposure in their neighborhood. How this neighborhood is defined can vary, however, leading to different approaches to quantification whose impacts on exposure levels remain unclear. We explore the relationship between neighborhood definition and exposure assessment. NO2, benzene, PM10 and PM2.5 exposure estimates were computed in the vicinity of 10,825 buildings using twelve exposure assessment techniques reflecting different definitions of "neighborhood". At the city scale, its definition does not significantly influence exposure estimates. It does impact levels at the building scale, however: at least a quarter of the buildings' exposure estimates for a 400 m buffer differ from the estimated 50 m buffer value (±1.0 µg/m(3) for NO2, PM10 and PM2.5; and ±0.05 µg/m(3) for benzene). This variation is significantly related to the definition of neighborhood. It is vitally important for investigators to understand the impact of chosen assessment techniques on exposure estimates.

Assessing residential exposure to urban noise using environmental models: does the size of the local living neighborhood matter?

Environmental epidemiological studies rely on the quantification of the exposure level in a surface defined as the subject's exposure area. For residential exposure, this area is often the subject's neighborhood. However, the variability of the size and nature of the neighborhoods makes comparison of the findings across studies difficult. This article examines the impact of the neighborhood's definition on environmental noise exposure levels obtained from four commonly used sampling techniques: address point, façade, buffers, and official zoning. A high-definition noise model, built on a middle-sized French city, has been used to estimate LAeq,24 h exposure in the vicinity of 10,825 residential buildings. Twelve noise exposure indicators have been used to assess inhabitants' exposure. Influence of urban environmental factors was analyzed using multilevel modeling. When the sampled area increases, the average exposure increases (+3.9 dB), whereas the SD decreases (-1.6 dB) (P<0.01). Most of the indicators differ statistically. When comparing indicators from the 50-m and 400-m radius buffers, the assigned LAeq,24 h level varies across buildings from -9.4 to +22.3 dB. This variation is influenced by urban environmental characteristics (P<0.01). On the basis of this study's findings, sampling technique, neighborhood size, and environmental composition should be carefully considered in further exposure studies.

El hábito de fumar en estudiantes preuniversitarios de La Habana, Cuba, 1980 / Smoking habits among preuniversitary students in Havana, Cuba, 1980

Se describen los objetivos, metodología y resultados de una investigación sobre el hábito de fumar en adolescentes, realizada mediante una encuesta en estudiantes de dos escuelas preuniversitarias de La Habana. Se cuantifican la prevalencia total del hábito de fumar por sexo y edad, la duración e intensidad del hábito, las asociaciones del hábito con algunas características de los núcleos familiares de los estudiantes, y las relaciones del hábito con el rendimiento y el ausentismo escolar, práctica de deportes y síntomas respiratorios (AU)

El habito de fumar en estudiantes preuniversitarios de la Habana, Cuba, 1980. / Smoking habits among preuniversitary students in La Habana, Cuba 1980

Se describen los objetivos, metodologia y resultados de una investigacion sobre el habito de fumar en adolescentes, realizada mediante una encuesta en estudiantes de dos escuelas preuniversitarias de La Habana. Se cuantifican la prevalencia total del habito de fumar por sexo y edad, la duracion e intensidad del habito, las asociaciones del habito con algunas caracteristicas de los nucleos familiares de los estudiantes, y las relaciones del habito con el rendimiento y el ausentismo escolar practica de deportes y sintomas respiratorios

El hábito de fumar en estudiantes preuniversitarios de La Habana, Cuba, 1980 / Smoking habits among preuniversitary students in Havana, Cuba, 1980

Se describen los objetivos, metodología y resultados de una investigación sobre el hábito de fumar en adolescentes, realizada mediante una encuesta en estudiantes de dos escuelas preuniversitarias de La Habana. Se cuantifican la prevalencia total del hábito de fumar por sexo y edad, la duración e intensidad del hábito, las asociaciones del hábito con algunas características de los núcleos familiares de los estudiantes, y las relaciones del hábito con el rendimiento y el ausentismo escolar, práctica de deportes y síntomas respiratorios (AU)