Fant 10010 publikasjoner. Viser side 295 av 401:
2019
2019
Tiltaksutredning for lokal luftkvalitet i Tromsø
Tiltaksutredningen, med handlingsplan og tiltak, skal bidra til å redusere luftforurensningen til et nivå som tilfredsstiller kravene i forurensningsforskriften. Tiltaksutredningen omfatter en kartlegging av luftkvaliteten i Tromsø ved trafikkberegninger og utslipps- og spredningsberegninger for PM10, PM2,5 og NO2 for Dagens situasjon 2016 og Framtidig situasjon 2023 med og uten tiltak mot svevestøv. Basert på resultatene fra beregningene og i samarbeid med oppdragsgiver og arbeidsgruppen, er det foreslått en revidert handlings- og beredskapsplan som skal behandles politisk.
NILU
2019
Effect of filter type in ventilation systems on NO2 concentrations in classrooms
This study was conducted to assess how different filter types in the ventilation system affect the indoor NO2 concentrations. Measurements were carried out in two classrooms and air intakes in a primary school located in Oslo, Norway. A regular F7 particle filter and an F7 combination filter with activated charcoal lin-ing were compared. NO2 concentrations were measured for five weeks during winter 2017 in a cross-over study design to compare: 1) NO2-levels in classrooms with regular filter (RF) versus combination filter (CF); 2) indoor/outdoor ratio with regular filter versus combination filter. One-hour average concentrations are reported during operating time of the ventilation system (6:00-23:00) and during hours with high (> 40 μg/m3) outdoor NO2 concentrations. The measured average NO2 concentrations in both classrooms with an RF were significantly higher than with a CF. The median CF/RF ratios for the two class-rooms were 0.50 and 0.81 during hours with high NO2 concentrations, and 0.48 and 1.00 during the period the ventilation system was operational. During hours with high NO2 concentrations, themedian indoor/outdoor ratios for the two class-rooms with an RF were above 1.00, while the corresponding ratios with a CF were 0.78 and 0.75. Our results demonstrate that a combination filter is more efficient than a regular filter in reducing NO2 concentrations in classrooms during hours with high out-door concentrations.
2019
BACKGROUND: In order to use in situ measurements to constrain urban anthropogenic emissions of carbon dioxide (CO2), we use a Lagrangian methodology based on diffusive backward trajectory tracer reconstructions and Bayesian inversion. The observations of atmospheric CO2 were collected within the Tokyo Bay Area during the Comprehensive Observation Network for TRace gases by AIrLiner (CONTRAIL) flights, from the Tsukuba tall tower of the Meteorological Research Institute (MRI) of the Japan Meteorological Agency and at two surface sites (Dodaira and Kisai) from the World Data Center for Greenhouse Gases (WDCGG).
RESULTS: We produce gridded estimates of the CO2 emissions and calculate the averages for different areas within the Kanto plain where Tokyo is located. Using these inversions as reference we investigate the impact of perturbing different elements in the inversion system. We modified the observations amount and location (surface only sparse vs. including aircraft CO2 observations), the background representation, the wind data used to drive the transport model, the prior emissions magnitude and time resolution and error parameters of the inverse model.
CONCLUSIONS: Optimized fluxes were consistent with other estimates for the unperturbed simulations. Inclusion of CONTRAIL measurements resulted in significant differences in the magnitude of the retrieved fluxes, 13% on average for the whole domain and of up to 21% for the spatiotemporal cells with the highest fluxes. Changes in the background yielded differences in the retrieved fluxes of up to 50% and more. Simulated biases in the modelled transport cause differences in the retrieved fluxes of up to 30% similar to those obtained using different meteorological winds to advect the Lagrangian trajectories. Perturbations to the prior inventory can impact the fluxes by ~ 10% or more depending on the assumptions on the error covariances. All of these factors can cause significant differences in the estimated flux, and highlight the challenges in estimating regional CO2 fluxes from atmospheric observations.
2019
Global Historical Stocks and Emissions of PBDEs
The first spatially and temporally resolved inventory of BDE28, 47, 99, 153, 183, and 209 in the anthroposphere and environment is presented here. The stock and emissions of PBDE congeners were estimated using a dynamic substance flow analysis model, CiP-CAFE. To evaluate our results, the emission estimates were used as input to the BETR-Global model. Estimated concentrations were compared with observed concentrations in air from background areas. The global (a) in-use and (b) waste stocks of ∑5BDE(28, 47, 99, 153, 183) and BDE209 are estimated to be (a) ∼25 and 400 kt and (b) 13 and 100 kt, respectively, in 2018. A total of 6 (0.3–13) and 10.5 (9–12) kt of ∑5BDE and BDE209, respectively, has been emitted to the atmosphere by 2018. More than 70% of PBDE emissions during production and use occurred in the industrialized regions, while more than 70% of the emissions during waste disposal occurred in the less industrialized regions. A total of 70 kt of ∑5BDE and BDE209 was recycled within products since 1970. As recycling rates are expected to increase under the circular economy, an additional 45 kt of PBDEs (mainly BDE209) may reappear in new products.
2019
2019
This report studies the distribution and fate of contaminants such as mercury (Hg), cyclic volatile methylated siloxanes (cVMS: D4, D5, D6), brominated flame retardants (BFR, PBDEs), alkylphenols, organic phosphorous flame retardants (oPFR), poly- and perfluorated alkyl substances (PFAS), new brominated flame retardants (nBFR) and UV-chemicals. Samples of the pelagic food web of Lake Mjøsa (zooplankton, Mysis, vendace, European smelt and brown trout) and the top predator brown trout in Lake Femunden are studied. Results are compared to environmental quality standards (EQS) and the time trends for major contaminants are studied.
Norsk institutt for vannforskning (NIVA)
2019
Recent Trends in Maintenance Costs for Façades Due to Air Pollution in the Oslo Quadrature, Norway
This study assesses changes since 1980 in the maintenance cost of the façades of the historical 17th to 19th century buildings of the Oslo Quadrature, Norway, due to atmospheric chemical wear, including the influence of air pollution. Bottom up estimations by exposure–response functions for an SO2 dominated situation reported in the literature for 1979 and 1995 were compared with calculations for the present (2002–2014) multi-pollutant situation. The present maintenance cost, relative to the total façade area, due to atmospheric wear and soiling was found to be about 1.6 Euro/m2 per year. The exposure to local air pollution, mainly particulate matter and NOx gases, contributed to 0.6 Euro/m2 (38%), of which the cost due to wear of renderings was about 0.4 Euro/m2 (22%), that due to the cleaning of glass was 0.2 Euro/m2 (11%), and that due to wear of other façade materials was 0.07 Euro/m2 (5%). The maintenance cost due to the atmospheric wear was found to be about 3.5%, and that due to the local air pollution about 1.1% of the total municipal building maintenance costs. The present (2002–2014) maintenance costs, relative to the areas of the specific materials, due to atmospheric wear are probably the highest for painted steel surfaces, about 8–10 Euro/m2, then about 2 Euro/m2 for façade cleaning and the maintenance of rendering, and down to 0.3 Euro/m2 for the maintenance of copper roofs. These costs should be adjusted with the importance of the wear relative to other reasons for the façade maintenance.
2019
2019
Individual variability in contaminants and physiological status in a resident Arctic seabird species
2019
2019