Found 10483 publications. Showing page 318 of 420:
2020
Environmental Contaminants in an Urban Fjord, 2019
This programme, “Environmental Contaminants in an Urban Fjord” has covered sampling and analyses of sediment and organisms in a marine food web of the Inner Oslofjord, in addition to samples of blood and eggs from herring gull. The programme also included inputs of pollutants via surface water (storm water), and effluent water and sludge from a sewage treatment plant. The bioaccumulation potential of the contaminants in the Oslo fjord food web was evaluated. The exposure to/accumulation of the contaminants was also assessed in birds. A vast number of chemical parameters have been quantified, in addition to some biological effect parameters in cod, and the report serves as a status description of the concentrations of these chemicals in different compartments of the Inner Oslofjord marine ecosystem.
Norsk institutt for vannforskning (NIVA)
2020
The Norwegian Arctic possesses a unique environment for the detection of new potential chemicals of emerging Arctic concern (CEACs) due to remoteness, sparse population and the low number of local contamination sources. Hence, a contaminant present in Arctic air is still considered a priority indication for its environmental stability and environmental mobility. Today, legacy persistent organic pollutants (POPs) and related conventional environmental pollutants are already well-studied because of their identification as Arctic pollutants in the 1980s. Many of them are implemented and reported in various national and international monitoring activities including the Arctic Monitoring and Assessment Programme (AMAP). These standard monitoring schemes, however, are based on compound-specific quantitative analytical methods. Under such conditions, the possibility for the identification of hitherto unidentified contaminants is limited and random at best. Today, new and advanced technological developments allow a broader, unspecific analytical approach as either targeted multicomponent analysis or suspect and non-target screening strategies. In order to facilitate such a wide range of compounds, a wide-scope sample clean-up method for high-volume air samples based on a combination of adsorbents was applied, followed by comprehensive two-dimensional gas chromatography separation and low-resolution time-of-flight mass spectrometric detection (GC × GC-LRMS). During the study reported here, simultaneous non-target and suspect screening were applied. The detection of over 700 compounds of interest in the particle phase and over 1200 compounds in the gaseous phase is reported. Of those, 62 compounds were confirmed with reference standards and 90 compounds with a probable structure (based upon mass spectrometric interpretation and library spectrum comparison). These included compounds already detected in Arctic matrices and compounds not detected previously (see also Fig. 1). In addition, 241 compounds were assigned a tentative structure or compound class. Hitherto unknown halogenated compounds, which are not listed in the mass spectral libraries used, were also detected and partly identified.
2020
2020
On the robustness of field calibration for smart air quality monitors
The robustness of field calibrated Air Quality Multi-sensors (AQM) performances to long term and/or mobile operation is still debated. Though accuracy generally exceeds the one of laboratory calibrations models, experimental results show that field calibration models cannot sustain optimal field performances due to changes occurring in operative conditions. Among them, the relocation of calibrated multi-sensors platforms and sensor drift are considered as the most relevant. In this work, we want to provide an answer to the general issue of field calibration robustness assessement. Analysing theoretical foundations and providing tools for determining the calibration model validity domain. In particular, by leveraging the probability distribution of target and interferent gas as well as environmental variables, measures of dissimilarity between calibration and operative phase conditions are considered to quantitatively capture the occurring change. A 6 months multiple nodes dataset including node relocations events in several sites have been processed for deriving nonlinear multivariate field calibrations whose robustness to changing conditions have been analysed. Kullback-Leibler, Euclidean and Hellinger dissimilarity measurements have been correlated with recorded performance degradation. Results show that quantifying relevant factors probability distribution changes allows to explain and predict performances of in field data driven calibration models. They also highlight the role of concept drift in explaining field performances ameliorating our capability to select optimal conditions in which a field calibration should be derived. Finally, smart air quality monitors could now autonomously detect the need for re-calibration.
2020
2020
Norge har et eksisterende overvåkingsnettverk for å måle effekter av luftforurensninger som forsuring, overgjødsling og
ozoneksponering i økosystemer. Ved eventuell implementering av nytt NEC‐direktiv «takdirektiv» (2016/2284/EU) må Norge
rapportere inn overvåkingsnettverk og resultater fra overvåking av effekter av luftforurensninger i økosystemer.
I denne rapporten er dagens overvåkingsnettverk vurdert med hensyn til de krav som stilles i nytt NEC‐direktiv. Resultater viste
at for innsjøer og elver er dagens overvåkingsnettverk relatert til forsuring tilfredsstillende. For overgjødsling av skog, skogsjord
og terrestrisk natur er det behov for oppgraderinger av overvåkingsnettverket. I forhold til ozonskader i vegetasjon er det behov
for oppgraderinger av dagens overvåkingsnettverk.
Det vil påløpe kostnader for opprettelse av nye overvåkingsstasjoner og oppgraderinger av dagens overvåkingsnettverk.
Estimerte kostnader for å dekke mangler i eksisterende overvåkingsnettverk er angitt i rapporten.
Norsk institutt for vannforskning (NIVA)
2020
The ClairCity Horizon2020 project aims to contribute to citizen-inclusive air quality and carbon policy making in middle-sized European cities. It does so by investigating citizens’ current behaviours as well as their preferred future behaviours and policy measures in six European cities1 through an extensive citizen and stakeholder engagement process. The project also models the possible future impacts of citizens’ policy preferences and examines implementation possibilities for these measures in the light of the existing institutional contexts in each city (Figure 0-1). This report summarises the main policy results for Ljubljana.
ClairCity Project
2020
Source Quantification of South Asian Black Carbon Aerosols with Isotopes and Modeling
Black carbon (BC) aerosols perturb climate and impoverish air quality/human health—affecting ∼1.5 billion people in South Asia. However, the lack of source-diagnostic observations of BC is hindering the evaluation of uncertain bottom-up emission inventories (EIs) and thereby also models/policies. Here, we present dual-isotope-based (Δ14C/δ13C) fingerprinting of wintertime BC at two receptor sites of the continental outflow. Our results show a remarkable similarity in contributions of biomass and fossil combustion, both from the site capturing the highly populated highly polluted Indo-Gangetic Plain footprint (IGP; Δ14C-fbiomass = 50 ± 3%) and the second site in the N. Indian Ocean representing a wider South Asian footprint (52 ± 6%). Yet, both sites reflect distinct δ13C-fingerprints, indicating a distinguishable contribution of C4-biomass burning from peninsular India (PI). Tailored-model-predicted season-averaged BC concentrations (700 ± 440 ng m–3) match observations (740 ± 250 ng m–3), however, unveiling a systematically increasing model-observation bias (+19% to −53%) through winter. Inclusion of BC from open burning alone does not reconcile predictions (fbiomass = 44 ± 8%) with observations. Direct source-segregated comparison reveals regional offsets in anthropogenic emission fluxes in EIs, overestimated fossil-BC in the IGP, and underestimated biomass-BC in PI, which contributes to the model-observation bias. This ground-truthing pinpoints uncertainties in BC emission sources, which benefit both climate/air-quality modeling and mitigation policies in South Asia.
2020
Satellite validation strategy assessments based on the AROMAT campaigns
The Airborne ROmanian Measurements of Aerosols and Trace gases (AROMAT) campaigns took place in Romania in September 2014 and August 2015. They focused on two sites: the Bucharest urban area and large power plants in the Jiu Valley. The main objectives of the campaigns were to test recently developed airborne observation systems dedicated to air quality studies and to verify their applicability for the validation of space-borne atmospheric missions such as the TROPOspheric Monitoring Instrument (TROPOMI)/Sentinel-5 Precursor (S5P). We present the AROMAT campaigns from the perspective of findings related to the validation of tropospheric NO2, SO2, and H2CO. We also quantify the emissions of NOx and SO2 at both measurement sites.
We show that tropospheric NO2 vertical column density (VCD) measurements using airborne mapping instruments are well suited for satellite validation in principle. The signal-to-noise ratio of the airborne NO2 measurements is an order of magnitude higher than its space-borne counterpart when the airborne measurements are averaged at the TROPOMI pixel scale. However, we show that the temporal variation of the NO2 VCDs during a flight might be a significant source of comparison error. Considering the random error of the TROPOMI tropospheric NO2 VCD (σ), the dynamic range of the NO2 VCDs field extends from detection limit up to 37 σ (2.6×1016 molec. cm−2) and 29 σ (2×1016 molec. cm−2) for Bucharest and the Jiu Valley, respectively. For both areas, we simulate validation exercises applied to the TROPOMI tropospheric NO2 product. These simulations indicate that a comparison error budget closely matching the TROPOMI optimal target accuracy of 25 % can be obtained by adding NO2 and aerosol profile information to the airborne mapping observations, which constrains the investigated accuracy to within 28 %. In addition to NO2, our study also addresses the measurements of SO2 emissions from power plants in the Jiu Valley and an urban hotspot of H2CO in the centre of Bucharest. For these two species, we conclude that the best validation strategy would consist of deploying ground-based measurement systems at well-identified locations.
2020
Aerosol particles are essential constituents of the Earth's atmosphere, impacting the earth radiation balance directly by scattering and absorbing solar radiation, and indirectly by acting as cloud condensation nuclei. In contrast to most greenhouse gases, aerosol particles have short atmospheric residence times, resulting in a highly heterogeneous distribution in space and time. There is a clear need to document this variability at regional scale through observations involving, in particular, the in situ near-surface segment of the atmospheric observation system. This paper will provide the widest effort so far to document variability of climate-relevant in situ aerosol properties (namely wavelength dependent particle light scattering and absorption coefficients, particle number concentration and particle number size distribution) from all sites connected to the Global Atmosphere Watch network. High-quality data from almost 90 stations worldwide have been collected and controlled for quality and are reported for a reference year in 2017, providing a very extended and robust view of the variability of these variables worldwide. The range of variability observed worldwide for light scattering and absorption coefficients, single-scattering albedo, and particle number concentration are presented together with preliminary information on their long-term trends and comparison with model simulation for the different stations. The scope of the present paper is also to provide the necessary suite of information, including data provision procedures, quality control and analysis, data policy, and usage of the ground-based aerosol measurement network. It delivers to users of the World Data Centre on Aerosol, the required confidence in data products in the form of a fully characterized value chain, including uncertainty estimation and requirements for contributing to the global climate monitoring system.
2020
2020
Feasibility study for asphalt rubber pavements in Norway. ‘Rubber Road’ feasibility study.
RubberRoad proposes to use rubber from used tires in the production of asphalt for road and bicycle ways. This recycling approach has not gained much attention in Norway despite its apparent advantages, such as noise reduction, increased durability, safer shock impact, and reduced climate and environmental impacts. The Life Cycle Analysis carried out during this project feasibility study has demonstrated a series of environmental benefits in the use of rubber in asphalt production. It has also helped identify relevant knowledge gaps related to the use phase of the rubberized asphalt and its impact to noise, air and micro-plastic pollution. Better understanding of these effects would probably result in even larger environmental benefits of rubberized asphalt with respect to standard asphalt production. However, while the tire recycling industry is generally positive to the disposal of used tires in asphalt production, additional incentives need to be put in place for the Norwegian asphalt producers to consider actively contributing to this development.
NILU
2020