Air pollution, especially in urban areas, is the result of a complex mixture of natural and anthropogenic emissions and their atmospheric processing. It causes millions of premature deaths worldwide and affects plant metabolism, which in turn alters the emissions of Biogenic Volatile Organic Compound (BVOCs) by plants. By taking the subtropical Metropolitan Area of São Paulo (MASP) as a natural laboratory, the BIOMASP+ project (BIOsphere-atmosphere interactions in the Metropolitan Area of São Paulo - plus ) aims to evaluate the interplay between the biosphere and secondary pollution (ozone and SOA formation and aging). The Brazilian Atlantic Forest (Mata Atlântica) is the target ecosystem as the fifth biodiversity hotspot in the world. Here we present the scientific motivations of the project, its methodology and the preliminary observations from the Special Observation Periods of year 2023 (SOP1, 2, 3 and 4). BIOMASP+ is (i) integrative, by combining in-situ/remote/laboratory observations and modeling, (ii) multidisciplinary, addressing micrometeorology, urban climate, atmospheric chemistry and biology. The project involves multiple nested scales: from leaf to above-canopy levels, from very short time (microseconds) to multi-year scale, from few millimeters (turbulence scale) to synoptic scale. In particular, the experimental effort relies on the implementation of two contrasting supersites (primary forest and urban forest) with a 30-m and 20-m flux towers, respectively, and a variety of state-of-the-art instruments. Ambient observations and the quantification of BVOC emissions have highlighted the complex interactions between meteorology, atmospheric composition of pollution, biogenic emissions of representative remnants of the Atlantic Forest and anthropogenic emissions.
Perfluorooctanoic acid (PFOA) has been widely detected in human serum, umbilical cord blood and breast milk, indicating potential prenatal and lactational exposure of the general population. Experimental studies in animal models have raised concerns regarding developmental and neurotoxic effects of PFOA. Mice are commonly used in developmental neurotoxicity studies to investigate the effect of exposure to pollutants. Neurodevelopmental research frequently relies on neurobehavioral observations, without measuring or evaluating the corresponding internal concentrations of pollutants within the offspring's brain. Physiologically Based Pharmacokinetic (PBPK) models allow predicting the toxicokinetic behavior of xenobiotics in an organism, based on chemical and physiological properties. In this study, a generic mouse PBPK model including gestation and lactation has been developed. This model comprises six compartments for dams and five for the pup including the brain compartment. It describes the dam's growth from birth and pup from the early embryonic stages, as well as the changes in organ volumes and blood flows. The generic mouse model has been parametrized for PFOA. This model enables the simulation of PFOA distribution and its internal concentration in the offspring's brain resulting from maternal oral exposure. Our case study demonstrates the use of a mouse-specific PBPK model, incorporating gestation and lactation in an in vitro in vivo extrapolation (IVIVE) context, to integrate New Approach Methodologies (NAMs) into neurotoxicity assessment.
Background Iron powder appears to be a promising solution for long-term energy storage and (inter-) continental transport, as it is safe to store and does not require energy to maintain its state, unlike, for instance, liquefied hydrogen. However, while the fundamental research is well underway, large-scale implementation is still in its early stages, with a growing number of promising demonstrators emerging. Methods This article contributes to the large-scale implementation of iron as an energy carrier by presenting a round-robin test of four iron powders currently used in research and larger-scale demonstrators. These powders were tested on their safety characteristics in the standard 20 L apparatus across eight European countries. Results The resulting data are intended to support future standardization efforts using different iron samples as standardized fuel. All tested powders were classified either as non-explosible or as belonging to the category of marginally explosible dusts (Class 1). This provides a clear picture of the level of explosion protection measures that need to be considered for the safe use of iron powders in energy carrier applications. Conclusions Along with that, the study detected variations in the results and pointed to shortcomings in the current standards that may cause such discrepancies. These findings emphasize the importance of improving testing procedures to support standardization and ensure the safe use of iron powder as an energy carrier using an a-priori-approach rather than subsequent testing.
Groundwater-induced internal erosion of finer soil fractions is critical for initiating granular slope collapse, but developing accurate computational models to capture coupled unsaturated seepage, particle migration, and hydro-mechanical property evolution of soils remains challenging. This study proposes a novel three-phase five-component mathematical model based on mixture theory to describe multiphysics phenomena in seepage-induced erosion in gap-graded granular soils. To enhance model accuracy, an improved micromechanics-based multiscale model is integrated to account for the specific moisture content and grading-dependent mechanical behavior of the porous medium experiencing seepage erosion. The computational framework innovatively employs an enhanced stabilized finite element method to eliminate numerical oscillations, validated via comparison with analytical solutions. The spatio-temporal evolution of the eroded zone and hydro-mechanical response of a reconstituted flume slope were successfully identified. Numerical results show volumetric settlements and shear sliding are major consequences of internal erosion, with soil property degradation near the slope toe accelerating failure. Neglecting internal erosion delays predicted failure onset and underestimates collapse severity. The proposed framework proves efficient and reliable for predicting seepage-induced slope failure initiation.
This study quantifies the impact of residential wood heating on winter air quality in France, including street-level analysis in Paris. It applies a multi-scale model to simulate regulated and emerging pollutants, such as organic matter (OM), black carbon (BC), and ultrafine particles (UFP), associated with health risks. Wood-burning emissions in Île-de-France and Paris were estimated using detailed local surveys, a new classification of appliances and emission factors accounting for condensable compounds. Over France, emissions were quantified from the EMEP top-down emission inventory, with post-estimated condensables. Wood burning is a major contributor to particulate pollution: in France, it accounts for 39.9% of PM2.5, 72.4% of BC, and 76.7% of OM. In Paris, contributions are similar, except for BC (27.2% at street level), influenced by other sources, as road traffic. Contributions to UFP are lower, ranging from 7% in Parisian streets to 15.5% over France. Wood burning significantly contributes to outdoor population exposure in Paris (33% for PM2.5, 20% for BC, and 70% for OM), with heating emissions mostly from auxiliary and comfort use (98%). Two 2030 scenarios were evaluated: business-as-usual (BAU) and a national emission-reduction objective. Under BAU, PM2.5 emissions and concentrations decline by 32.6% and 13.4% over France, and by 18.1% and 14.2% in Paris. Concentration reductions are smaller than emission reductions because some PM2.5 components (e.g. inorganics) are unaffected by wood-burning controls. The national objective scenario achieves larger impacts, typically 50%-70% greater than BAU, reducing PM2.5 concentrations of about 22%-24% in urban and street environments. Environmental Implications Health risks of fine particles depend on their composition and size, with black carbon, organics, and ultrafine particles emerging as key indicators. Our results indicate that reducing residential wood heating is an effective policy lever to mitigate wintertime particulate pollution in urban areas. In Paris, a large share of emissions arises from auxiliary and comfort heating, suggesting that targeted measures addressing non-essential wood use could deliver substantial air-quality benefits. The transition to newer heating technologies should be carefully evaluated to ensure that improvements in mass-based air quality are not offset by increased ultrafine particle emissions, which are not covered by current regulations but may have important health implications.
