Found 9887 publications. Showing page 192 of 396:
2008
2008
2017
Land cover and traffic data inclusion in PM mapping
Annual European-wide air quality maps have been produced using geostatistical techniques for many years and is based primarily on air quality measurements. The mapping method follows in principle the sequence of regression – interpolation – merging. It combines monitoring data, chemical transport model outputs and other supplementary data (such as altitude and meteorology) using a linear regression model followed by kriging of its residuals (‘residual kriging’), applied separately for rural and urban background areas. The rural and urban background map layers are
subsequently merged on basis of population densities into one final concentration map for Europe.
Inclusion of land cover and road type data among the set of the supplementary data demonstrated to improve the quality of urban and rural background layers in the NO2 map and is currently routinely applied in the NO2 mapping. In addition, an urban traffic map layer based on the measurement data from traffic stations is constructed and takes art in the merging process with the rural and urban background map layers to reach a final NO2 map.
This report examines now – due to its proved added value in the NO2 mapping – whether for PM10 and PM2.5 the similar method provides also sufficient added value to include it on a routinely basis in the production of the final concentration map and population exposure estimates.. It concerns the inclusion of land cover data and road type data in the background map layers, as well as the inclusion of the urban traffic layer based on traffic measurement stations. The analysis is done based on 2015 data, being the most recent year with all data needed available when this study started.
ETC/ACM
2019
2014
2015
2001
2014
2005
Lack of mutagenicity of TiO2 nanoparticles in vitro despite cellular and nuclear uptake
The potential genotoxicity of titanium dioxide (TiO2) nanoparticles (NPs) is a conflictive topic because both positive and negative findings have been reported. To add clarity, we have carried out a study with two cell lines (V79–4 and A549) to evaluate the effects of TiO2 NPs (NM-101), with a diameter ranging from 15 to 60 nm, at concentrations 1–75 μg/cm2. Using two different dispersion procedures, cell uptake was determined by Transmission Electron Microscopy (TEM). Mutagenicity was evaluated using the Hprt gene mutation test, while genotoxicity was determined with the comet assay, detecting both DNA breaks and oxidized DNA bases (with formamidopyrimidine glycosylase - Fpg). Cell internalization, as determined by TEM, shows TiO2 NM-101 in cytoplasmic vesicles, as well as close to and inside the nucleus. Such internalization did not depend on the state of agglomeration, nor the dispersion used. In spite of such internalization, no cytotoxicity was detected in V79–4 cells (relative growth activity and plating efficiency assays) or in A549 cells (AlamarBlue assay) after exposure lasting for 24 h. However, a significant decrease in the relative growth activity was detected at longer exposure times (48 and 72 h) and at the highest concentration 75 µg/cm2. When the modified enzyme-linked alkaline comet assay was performed on A549 cells, although no significant induction of DNA damage was detected, a positive concentration-effects relationship was observed (Spearman’s correlation = 0.9, p 0.0001). Furthermore, no significant increase of DNA oxidized purine bases was observed. When the frequency of Hprt gene mutants was determined in V79–4 cells, no increase was observed in the exposed cells, relative to the unexposed cultures. Our general conclusion is that, under our experimental conditions, TiO2 NM-101 exposure does not exert mutagenic effects despite the evidence of NP uptake by V79–4 cells.
2022
2024
2004
2017
I prosjektet ble det utført målinger av kvikksølv (Hg) i luft ved en stasjon og prøvetaking og analyse av Hg i nedbør ved to stasjoner, samt analyse av Hg i 14 storfisk fra Pasvikvassdraget. Måleresultatene for Hg i luft i Karpdalen viser bakgrunnsnivåer rundt 1,3 - 1,4 ng/m3. Forhøyede konsentrasjoner av Hg samsvarer med forhøyede konsentrasjoner av SO2 (episoder). Det er derfor sannsynliggjort at episodene skyldes utslipp fra samme kilde eller kildeområder på russisk side. Konsentrasjoner av Hg i nedbør og avsetning er høyere på Svanvik enn i Karpdalen, men lavere enn bakgrunnsstasjoner i Sør-Norge. Analyser av Hg i fisk viser at de største fiskene (gjedde, ørret, abbor) har verdier over grenseverdi på 0,5 mg/kg. Sik viste lave verdier.
NILU
2018
Målet er å belyse hvilke kvalitetskrav som bør stilles til luftkvalitetsberegninger, kart og data til ulike bruksformål slik disse er formulert i norsk regelverk, herunder Forurensningsloven, Folkehelseloven, Plan- og bygningsloven, Retningslinje for behandling av luftkvalitet i arealplanlegging (T1520) m.fl. Miljødirektoratet ønsker å sikre god, enhetlig og sammenlignbar kvalitet og praksis på utredninger av luftkvalitet og har bedt om anbefalinger i form av denne rapporten.
For å få et best mulig grunnlag for å vurdere behovet for veiledning og kvalitetskriterier for ulike anvendelser, har det vært fokus på å innhente informasjon og innspill fra ulike brukergrupper og fagmiljøer. Det er gjennomført en spørreundersøkelse og det er arrangert flere møter og åpne kommentarrunder med ulike brukergrupper og fagmiljøer. Siden eventuelle kvalitetskrav vil kunne ha betydning for konkurranse i markedet og påvirke ressursbruken både hos private aktører og myndigheter, har brukermedvirkning vært et viktig element i dette arbeidet etter ønske fra oppdragsgiver.
NILU
2018
2003
2003
2004
2002
2002