Found 9759 publications. Showing page 98 of 391:
2019
2019
Rapporten presenterer resultatene fra målinger foretatt i Quintero-Puchuncaví regionen (Chile) for å kartlegge flyktige
organiske forbindelser (VOC). To ulike metoder ble benyttet, en kvantitativ (kanister prøvetaker / analyse med Medusa/GCMS) og en semi-kvantitativ (Tenax TA / analyse med GC-MS). NILU evaluerte resultatene av 4 forbindelser (metylkloroform, nitrobenzen, isobutan og toluen), som tidligere rapporter viste meget høye konsentrasjoner av og som har vært mye omtalt i media. NILUs måleresultater viser mye lavere konsentrasjoner, og konkluderer med at målingene som ble foretatt tidligere ikke ble riktig kalibrert. Den gjennomsnittlige konsentrasjonen av benzen var 1,0 μg/m3 i industriområder og 0,3 μg/m3 i bolig- / bakgrunnsområder, begge lavere enn internasjonale grenseverdier. Hovedforbindelsene i utslippene fra industriområdene er lette hydrokarboner, som ble påvist ved lave konsentrasjonsnivåer.
NILU
2019
2019
2019
Science Press
2019
Norwegian Scientific Committee for Food and Environment (VKM)
2019
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
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
SESS report 2018. The State of Environmental Science in Svalbard – an annual report.
Svalbard Integrated Arctic Earth Observing System (SIOS)
2019
2019
2019
Two years of continuous in situ measurements of Arctic low‐level clouds have been made at the Mount Zeppelin Observatory (78°56′N, 11°53′E), in Ny‐Ålesund, Spitsbergen. The monthly median value of the cloud particle number concentration (Nc) showed a clear seasonal variation: Its maximum appeared in May–July (65 ± 8 cm−3), and it remained low between October and March (8 ± 7 cm−3). At temperatures warmer than 0 °C, a clear correlation was found between the hourly Nc values and the number concentrations of aerosols with dry diameters larger than 70 nm (N70), which are proxies for cloud condensation nuclei (CCN). When clouds were detected at temperatures colder than 0 °C, some of the data followed the summertime Nc to N70 relationship, while other data showed systematically lower Nc values. The lidar‐derived depolarization ratios suggested that the former (CCN‐controlled) and latter (CCN‐uncontrolled) data generally corresponded to clouds consisting of supercooled water droplets and those containing ice particles, respectively. The CCN‐controlled data persistently appeared throughout the year at Zeppelin. The aerosol‐cloud interaction index (ACI = dlnNc/(3dlnN70)) for the CCN‐controlled data showed high sensitivities to aerosols both in the summer (clean air) and winter–spring (Arctic haze) seasons (0.22 ± 0.03 and 0.25 ± 0.02, respectively). The air parcel model calculations generally reproduced these values. The threshold diameters of aerosol activation (Dact), which account for the Nc of the CCN‐controlled data, were as low as 30–50 nm when N70 was less than 30 cm−3, suggesting that new particle formation can affect Arctic cloud microphysics.
American Geophysical Union (AGU)
2019
NILU - Norsk institutt for luftforskning har på oppdrag for Boliden Odda AS, utført sprednings- og avsetningsberegninger i forbindelse med utslipp fra sinkproduksjonsanlegget. Studien beregner luftkonsentrasjon og avsetning av svovel (forsuring), og konsentrasjon av metaller/svevestøv ved dagens sinkproduksjon og ved en planlagt utvidelse. Timesmiddel-, døgnmiddel- og årsmiddel-konsentrasjon av SO2 og PM10 er beregnet til å være innenfor grenseverdier og luftkvalitetskriterier ved dagens og utvidet produksjon. Beregningene viser mulig overskridelse av målsetningsverdien for kadmium ved en utvidelse av produksjonen. Utvidelse i produksjon gir et ytterligere bidrag til overskridelsen av tålegrensen (forsuring) i området rundt Odda. Økningen i avsetning forøvrig er beregnet å være i områder hvor tålegrensen er mer robust.
NILU
2019