Found 9886 publications. Showing page 102 of 396:
2019
NILU’s Environmental Management Report 2018
One of NILU’s main goals is to study the impact of pollution and supply decision-makers with a sound scientific platform for choosing measures to reduce the negative impacts. Furthermore, it is very important for the institute to have control of the impact the institute’s own activities may have on the environment and to reduce negative impacts as far as possible.
NILU has for many years been working to improve the status of the environment and to reduce negative impacts. In order to
take this one step further, it was decided that the institute should restructure the work according to a relevant environmental standard and to seek certification according to the same standard.
The chosen standard is ISO 14001 (Environmental management systems—Requirements with guidance for use) and NILU
achieved certification according to this standard in October 2010. This report summarizes the results of the system in 2018.
NILU
2019
There is little information to decision support in air traffic management in case of nuclear releases into the atmosphere. In this paper, the dose estimation due to both, external exposure (i.e. cloud immersion, deposition inside and outside the aircraft), and due to internal exposure (i.e, inhalation of radionuclides inside the aircraft) to passengers and crew is calculated for a worst-case emergency scenario. The doses are calculated for different radionuclides and activities. Calculations are mainly considered according to International Commission on Radiological Protection (ICRP) recommendations and Monte Carlo simulations. In addition, a discussion on potential detectors installed inside the aircraft for monitoring the aerosol concentration and the ambient dose equivalent rate, H*(10), for during-flight monitoring and early warning is provided together with the evaluation of a response of a generic detector. The results show that the probability that a catastrophic nuclear accident would produce significant radiological doses to the passengers and crew of an aircraft is very low. In the worst-case scenarios studied, the maximum estimated effective dose was about 1 mSv during take-off or landing operations, which is the recommended yearly threshold for the public. However, in order to follow the ALARA (As Low As Reasonably Achievable) criteria and to avoid aircraft contamination, the installation of radiological detectors is considered. This would, on one hand help the pilot or corresponding decision maker to decide about the potential change of the route and, on the other, allow for gathering of 4D data for future studies.
Elsevier
2019
Environmental impacts of a chemical looping combustion power plant
Chemical Looping Combustion (CLC) is a promising CO2 capture option since it inherently separates CO2 from other flue components, theoretically with low energy penalty. Here, a Life Cycle Assessment model was developed of a theoretical hybrid CLC (HCLC) power plant facility utilising experimental data for CuO based oxygen carrier (OC) production and oxygen capacity. Power plant models with and without post-combustion CO2 capture, recognised as the most mature capture technology, acted as environmental performance targets. Results show that when OC is produced at lab-scale without optimisation, almost all (>99.9%) lifecycle impacts per kWh electricity from an HCLC plant derive from the specific OC material used, giving a total of ˜700 kg CO2eq/kWh. This is related to high electrical input required for OC processing, as well as high OC losses during production and from plant waste. Only when processing parameters are optimised and OC recycling from plant waste is implemented - reducing fresh OC needs – is the environmental impact lower than the conventional technologies studied (e.g. 0.2 kg CO2 eq/kWh vs. ˜0.3-1 kg CO2 eq/kWh, respectively). Further research should thus focus on identifying OCs that do not require energy intensive processing and can endure repeated cycles, allowing for recycling.
Elsevier
2019
2019
2019
2019
This report presents the results from a screening study of volatile organic compounds (VOCs) in the Quintero-Puchuncaví
region (Chile). Two different methods were selected, one quantitative (canisters samplers / analysis by Medusa/GC-MS) and a second semi-quantitative (Tenax TA/analysis by GC-MS). NILU evaluated the results of 4 compounds (methyl chloroform,
nitrobenzene, iso-butane and toluene), which were previously reported at very high concentrations and intensively
discussed in the media. NILU’s measurement results show much lower concentrations and it was concluded that the former
measurements were done with a significant error in the calibration. The average concentration of ambient benzene was 1.0 µg/m3 at industrial areas and 0.3 µg/m3 at the residential/background areas, both lower than international limit values. The main compounds emitted from the industrial areas are light hydrocarbons, which were detected at low concentration levels.
NILU
2019
2019
2019
Science Press
2019
Norwegian Scientific Committee for Food and Environment (VKM)
2019
The carbonaceous aerosol accounts for an important part of total aerosol mass, affects human health and climate through its effects on physical and chemical properties of the aerosol, yet the understanding of its atmospheric sources and sinks is still incomplete. This study shows the state-of-the-art in modelling carbonaceous aerosol over Europe by comparing simulations performed with seven chemical transport models (CTMs) currently in air quality assessments in Europe: CAMx, CHIMERE, CMAQ, EMEP/MSC-W, LOTOS-EUROS, MINNI and RCGC. The simulations were carried out in the framework of the EURODELTA III modelling exercise and were evaluated against field measurements from intensive campaigns of European Monitoring and Evaluation Programme (EMEP) and the European Integrated Project on Aerosol Cloud Climate and Air Quality Interactions (EUCAARI). Model simulations were performed over the same domain, using as much as possible the same input data and covering four seasons: summer (1–30 June 2006), winter (8 January – 4 February 2007), autumn (17 September- 15 October 2008) and spring (25 February - 26 March 2009). The analyses of models’ performances in prediction of elemental carbon (EC) for the four seasons and organic aerosol components (OA) for the last two seasons show that all models generally underestimate the measured concentrations. The maximum underestimation of EC is about 60% and up to about 80% for total organic matter (TOM). The underestimation of TOM outside of highly polluted area is a consequence of an underestimation of secondary organic aerosol (SOA), in particular of its main contributor: biogenic secondary aerosol (BSOA). This result is independent on the SOA modelling approach used and season. The concentrations and daily cycles of total primary organic matter (TPOM) are generally better reproduced by the models since they used the same anthropogenic emissions. However, the combination of emissions and model formulation leads to overestimate TPOM concentrations in 2009 for most of the models. All models capture relatively well the SOA daily cycles at rural stations mainly due to the spatial resolution used in the simulations. For the investigated carbonaceous aerosol compounds, the differences between the concentrations simulated by different models are lower than the differences between the concentrations simulated with a model for different seasons.
Elsevier
2019
2019
Carbonaceous aerosol (total carbon, TCp) was source apportioned at nine European rural background sites, as part of the European Measurement and Evaluation Programme (EMEP) Intensive Measurement Periods in fall 2008 and winter/spring 2009. Five predefined fractions were apportioned based on ambient measurements: elemental and organic carbon, from combustion of biomass (ECbb and OCbb) and from fossil-fuel (ECff and OCff) sources, and remaining non-fossil organic carbon (OCrnf), dominated by natural sources.
OCrnf made a larger contribution to TCp than anthropogenic sources (ECbb, OCbb, ECff, and OCff) at four out of nine sites in fall, reflecting the vegetative season, whereas anthropogenic sources dominated at all but one site in winter/spring. Biomass burning (OCbb + ECbb) was the major anthropogenic source at the central European sites in fall, whereas fossil-fuel (OCff + ECff) sources dominated at the southernmost and the two northernmost sites. Residential wood burning emissions explained 30 %–50 % of TCp at most sites in the first week of sampling in fall, showing that this source can be the dominant one, even outside the heating season. In winter/spring, biomass burning was the major anthropogenic source at all but two sites, reflecting increased residential wood burning emissions in the heating season. Fossil-fuel sources dominated EC at all sites in fall, whereas there was a shift towards biomass burning for the southernmost sites in winter/spring.
Model calculations based on base-case emissions (mainly officially reported national emissions) strongly underpredicted observational derived levels of OCbb and ECbb outside Scandinavia. Emissions based on a consistent bottom-up inventory for residential wood burning (and including intermediate volatility compounds, IVOCs) improved model results compared to the base-case emissions, but modeled levels were still substantially underestimated compared to observational derived OCbb and ECbb levels at the southernmost sites.
Our study shows that natural sources are a major contributor to carbonaceous aerosol in Europe, even in fall and in winter/spring, and that residential wood burning emissions are equally as large as or larger than that of fossil-fuel sources, depending on season and region. The poorly constrained residential wood burning emissions for large parts of Europe show the obvious need to improve emission inventories, with harmonization of emission factors between countries likely being the most important step to improve model calculations for biomass burning emissions, and European PM2.5 concentrations in general.
2019
Europe's urban air quality — re-assessing implementation challenges in cities
This report analyses the implementation of EU air quality legislation at the urban level and identifies some of the reasons behind persistent air quality problems in Europe's cities. It is produced in cooperation with 10 cities involved in a 2013 Air Implementation Pilot project: Antwerp (Belgium), Berlin (Germany), Dublin (Ireland), Madrid (Spain), Malmö (Sweden), Milan (Italy), Paris (France), Plovdiv (Bulgaria), Prague (Czechia) and Vienna (Austria).
European Environment Agency
2019
Arctic-breeding geese acquire resources for egg production from overwintering and breeding grounds, where pollutant exposure may differ. We investigated the effect of migration strategy on pollutant occurrence of lipophilic polychlorinated biphenyls (PCBs) and protein-associated poly- and perfluoroalkyl substances (PFASs) and mercury (Hg) in eggs of herbivorous barnacle geese (Branta leucopsis) from an island colony on Svalbard. Stable isotopes (δ13C and δ15N) in eggs and vegetation collected along the migration route were similar. Pollutant concentrations in eggs were low, reflecting their terrestrial diet (∑PCB = 1.23 ± 0.80 ng/g ww; ∑PFAS = 1.21 ± 2.97 ng/g ww; Hg = 20.17 ± 7.52 ng/g dw). PCB concentrations in eggs increased with later hatch date, independently of lipid content which also increased over time. Some females may remobilize and transfer more PCBs to their eggs, by delaying migration several weeks, relying on more polluted and stored resources, or being in poor body condition when arriving at the breeding grounds. PFAS and Hg occurrence in eggs did not change throughout the breeding season, suggesting migration has a greater effect on lipophilic pollutants. Pollutant exposure during offspring production in Arctic-breeding migrants may result in different profiles, with effects becoming more apparent with increasing trophic levels.
2019
2019
The comet assay applied to HepG2 liver spheroids
In accordance with the 3 Rs to reduce in vivo testing, more advanced in vitro models, moving from 2D monolayer to 3D cultures, should be developed for prediction of human toxicity of industrial chemicals and environmental pollutants. In this study we compared cytotoxic and genotoxic responses induced by chemicals in 2D and 3D spheroidal cultures of the human liver cancer cell line HepG2.
HepG2 spheroids were prepared by hanging drop technology. Both 3D spheroids and 2D monolayer cultures were exposed to different chemicals (colchicine, chlorpromazine hydrochloride or methyl methanesulfonate) for geno- and cytotoxicity studies. Cytotoxicity was investigated by alamarBlue assay, flow cytometry and confocal imaging. DNA damage was investigated by the comet assay with and without Fpg enzyme for detection of DNA strand breaks and oxidized or alkylated base lesions.
The results from the cyto- and genotoxicity tests showed differences in sensitivity comparing the 2D and 3D HepG2 models. This study shows that human 3D spheroidal hepatocellular cultures can be successfully applied for genotoxicity testing by the comet assay and represent a promising advanced in vitro model for toxicity testing.
2019