Santé-environnement | EPFL Graph Search

thumb|350px|Un des défis de la santé environnementale est de mieux comprendre les relations systémiques et les effets synergiques et potentialisateurs des milliers de polluants présents dans l'environnement, entre eux et sur les différents organes.Certains effets sont différés (le cancer par exemple), ou sont possibles à de très faibles doses (perturbation endocrinienne), ou sont liés à des prédispositions génétiques. L'expression « santé-environnement » (ou santé environnementale), apparue à la fin du , désigne le champ commun aux hypothèses, connaissances et théories prospectives portant sur les relations possibles entre :

d'une part des variables environnementales (facteurs biogéographiques, pollutions et nuisances environnementales, etc.), mais aussi facteurs concernant la qualité de l'alimentation, de l'environnement intérieur (air, bruit, champ électromagnétique, radioactivité, etc.) et de travail (exposition à des toxiques, une fatigue anormale ou à des facteurs spécifiqu

High-resolution hybrid inversion of IASI ammonia columns to constrain US ammonia emissions using the CMAQ adjoint model

Jennifer Kaiser, Athanasios Nenes

Ammonia (NH3) emissions have large impacts on air quality and nitrogen deposition, influencing human health and the well-being of sensitive ecosystems. Large uncertainties exist in the "bottom-up" NH3 emission inventories due to limited source information and a historical lack of measurements, hindering the assessment of NH3-related environmental impacts. The increasing capability of satellites to measure NH3 abundance and the development of modeling tools enable us to better constrain NH3 emission estimates at high spatial resolution. In this study, we constrain the NH3 emission estimates from the widely used 2011 National Emissions Inventory (2011 NEI) in the US using Infrared Atmospheric Sounding Interferometer NH3 column density measurements (IASI-NH3) gridded at a 36 km by 36 km horizontal resolution. With a hybrid inverse modeling approach, we use the Community Multiscale Air Quality Modeling System (CMAQ) and its multiphase adjoint model to optimize NH3 emission estimates in April, July, and October. Our optimized emission estimates suggest that the total NH3 emissions are biased low by 26 % in 2011 NEI in April with overestimation in the Midwest and underestimation in the Southern States. In July and October, the estimates from NEI agree well with the optimized emission estimates, despite a low bias in hotspot regions. Evaluation of the inversion performance using independent observations shows reduced underestimation in simulated ambient NH3 concentra- tion in all 3 months and reduced underestimation in NH4 wet deposition in April. Implementing the optimized NH3 emission estimates improves the model performance in simulating PM2.5 concentration in the Midwest in April. The model results suggest that the estimated contribution of ammonium nitrate would be biased high in a priori NEI-based assessments. The higher emission estimates in this study also imply a higher ecological impact of nitrogen deposition originating from NH3 emissions.

COPERNICUS GESELLSCHAFT MBH2021

Influence of Temperature, VFA and pH on the inactivation of pathogens in anaerobic digestion of faecel sludge

Livia Jost

On-site sanitation technologies such as septic tanks are widely used in low- and middle-income countries. A comprehensive management of the accumulating faecal sludge (FS) is however missing in most contexts and uncontrolled disposal of FS results in serious public and environmental health risks. Given the high pathogen and organic matter content of FS it is urgent to find an appropriate method to treat FS. One promising, but little investigated technology to treat FS is anaerobic digestion (AD). The goal of the present thesis was to evaluate the influence of temperature, VFA and pH on the inactivation of pathogens in AD of synthetic FS. Ascaris suum eggs and bacteriophages MS2 and T4 were selected as model organisms for parasitic, respectively viral pathogens. At a temperature of 50°C, Ascaris suum eggs were inactivated after 6 h, independent of the pH and the VFA concentration. Bacteriophages MS2 and T4 were however not fully inactivated after 6 h at 50°C, their initial concentration was reduced by almost 99 % for T4 but only by 50 % for MS2. The pH had an effect on bacteriophages T4 but not on MS2. VFA concentration did not have an influence on the bacteriophages inactivation at the tested temperatures. Viruses and not parasites seem to be the critical organisms to consider in thermophilic AD (TAD) at 50°C of FS. Future research could therefore focus on the inactivation of human viruses in TAD as bacteriophages are conservative indicators for inactivation of human viruses.

2015

Vegetation Drastically Reduces Wind Erosion: An Implementation of the RWEQ in the Mongolian Gobi Steppe

Charlotte Gisèle Weil

Soil loss prevention is an important ecosystem service for protecting human and environmental health. Using spatiotemporal climate and environmental data of the Eastern Gobi Steppe, a region missing from previous studies of Mongolian wind-based soil erosion, we implemented the Revised Wind Erosion Equation (RWEQ) model to estimate soil loss. A replicable pipeline was developed to perform these computations, and made available openly. Soil loss was estimated on a monthly basis to analyze seasonal variations. The results show that the annual total soil loss was 61 x 10(10) kg over an area of 69.3 x 10(3) km(2), which is about 90 tonnes per hectare. Increasing fractional vegetation coverage to a uniform 50% coverage (doubling current vegetation coverage in every 1 km(2)) could reduce soil loss by 60%, highlighting the importance of protecting and increasing vegetation coverage in ecosystem service preservation.

MDPI2022

High-resolution hybrid inversion of IASI ammonia columns to constrain US ammonia emissions using the CMAQ adjoint model

Jennifer Kaiser, Athanasios Nenes

COPERNICUS GESELLSCHAFT MBH2021