Found 9990 publications. Showing page 11 of 400:
Estimating surface NO2 concentrations over Europe using Sentinel-5P TROPOMI
Satellite observations from instruments such as the TROPOspheric Monitoring Instrument (TROPOMI) show significant potential for monitoring the spatiotemporal variability of NO2, however they typically provide vertically integrated measurements over the tropospheric column. In this study, we introduce a machine learning approach entitled ‘S-MESH’ (Satellite and ML-based Estimation of Surface air quality at High resolution) that allows for estimating daily surface NO2 concentrations over Europe at 1 km spatial resolution based on eXtreme gradient boost (XGBoost) model using primarily observation-based datasets over the period 2019–2021. Spatiotemporal datasets used by the model include TROPOMI NO2 tropospheric vertical column density, night light radiance from the Visible Infrared Imaging Radiometer Suite (VIIRS), Normalized Difference Vegetation Index from the Moderate Resolution Imaging Spectroradiometer (MODIS), observations of air quality monitoring stations from the European Environment Agency database and modeled meteorological parameters such as planetary boundary layer height, wind velocity, temperature. The overall model evaluation shows a mean absolute error of 7.77 μg/m3, a median bias of 0.6 μg/m3 and a Spearman rank correlation of 0.66. The model performance is found to be influenced by NO2 concentration levels, with the most reliable predictions at concentration levels of 10–40 μg/m3 with a bias of
2024
The Opinion of the Scientific Committee on Health, Environmental and Emerging Risks advises the European Commission on whether the uses of titanium dioxide in toys and toy materials can be considered to be safe in light of the identified exposure, and the classification of titanium dioxide as carcinogenic category 2 after inhalation. Four toy products including casting kits, chalk, powder paints and white colour pencils containing various amounts of TiO2 as colouring agent were evaluated for inhalation risks. For the oral route, childrens’ lip gloss/lipstick, finger paint and white colour pencils were evaluated.
When it can be demonstrated with high certainty that no ultrafine fraction is present in pigmentary TiO2 preparations used in toys and toy materials, safe use with no or negligible risk for all products considered is indicated based on the exposure estimations of this Opinion. However, if an ultrafine fraction is assumed to be present, safe use is not indicated, except for white colour pencils.
2024
Mapping Plastic and Plastic Additive Cycles in Coastal Countries: A Norwegian Case Study
The growing environmental consequences caused by plastic pollution highlight the need for a better understanding of plastic polymer cycles and their associated additives. We present a novel, comprehensive top-down method using inflow-driven dynamic probabilistic material flow analysis (DPMFA) to map the plastic cycle in coastal countries. For the first time, we covered the progressive leaching of microplastics to the environment during the use phase of products and modeled the presence of 232 plastic additives. We applied this methodology to Norway and proposed initial release pathways to different environmental compartments. 758 kt of plastics distributed among 13 different polymers was introduced to the Norwegian economy in 2020, 4.4 Mt was present in in-use stocks, and 632 kt was wasted, of which 15.2 kt (2.4%) was released to the environment with a similar share of macro- and microplastics and 4.8 kt ended up in the ocean. Our study shows tire wear rubber as a highly pollutive microplastic source, while most macroplastics originated from consumer packaging with LDPE, PP, and PET as dominant polymers. Additionally, 75 kt of plastic additives was potentially released to the environment alongside these polymers. We emphasize that upstream measures, such as consumption reduction and changes in product design, would result in the most positive impact for limiting plastic pollution.
2024
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Monitoring of microplastics in the Norwegian environment (MIKRONOR) 2023
The MIKRONOR monitoring program aims to establish baseline levels of microplastics in the Norwegian environment and to identify potential sources and sinks. This third MIKRONOR report focuses mainly on results from air samples, including data on tyre wear particles (TWP), as well as river and fjord surface water samples, and their correlation to rainfall and river discharge levels. Additionally, it presents data from sand samples taken from an OSPAR beach in the outer Oslofjord. The results for 2023 provide evidence of the omnipresence of microplastics in the environment. However, levels were higher near cities and populated areas, with decreasing levels further from human activities. This trend was observed in both air and surface water samples. Sand samples from the OSPAR beach in the Oslofjord showed levels of microplastics comparable to, or slightly higher than studied eabches at Svalbard. Since no other beach studies have been conducted in the MIKRONOR program, it is difficult to determine typical microplastic levels on a beach in the outer Oslofjord. Determined levels of microplastics in the beach samples were comparable to levels in marine bottom sediment at remote areas along the coast and lower than levels in sediments from the Oslofjord. Main conclusions of this report highlight the need for further research into the processes that control the levels and variations of microplastics and TWPs, such as weather conditions, river discharge, and air mass movement. Sampling of different matrices should, where possible, be conducted using similar strategies and equipment to improve the comparability of results. Additionally, the high spatial and temporal variability between samples must be considered to determine the appropriate number of analyses needed to obtain reliable results.
Norsk institutt for vannforskning (NIVA)
2024
2024
Climate health risks to children and adolescents: exposures, policy and practice interventions
ETC/HE
2024
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Modelled sources of airborne microplastics collected at a remote Southern Hemisphere site
Airborne microplastics have emerged in recent years as ubiquitous atmospheric pollutants. However, data from the Southern Hemisphere, and remote regions in particular, are sparse. Here, we report airborne microplastic deposition fluxes measured during a five-week sampling campaign at a remote site in the foothills of the Southern Alps of New Zealand. Samples were collected over 24-hour periods for the first week and for 7-day periods thereafter. On average, atmospheric microplastic (MP) deposition fluxes were six times larger during the 24-hour sampling periods (150 MP m−2 day−1) than during the 7-day sampling periods (26 MP m−2 day−1), highlighting the importance of sampling frequency and deposition collector design to limit particle resuspension. Previous studies, many of which used weekly sampling frequencies or longer, may have substantially underestimated atmospheric microplastic deposition fluxes, depending on the study design. To identify likely sources of deposited microplastics, we performed simulations with a global dispersion model coupled with an emissions inventory of airborne microplastics. Modelled deposition fluxes are in good agreement with observations, highlighting the potential for this method in tracing sources of deposited microplastics globally. Modelling indicates that sea-spray was the dominant source when microplastics underwent long-range atmospheric transport, with a small contribution from road dust.
2024
Spredningsberegninger Ferrozink Trondheim AS. Dokumentasjon i forbindelse med utslippstillatelse
NILU
2024