Found 10008 publications. Showing page 61 of 401:
2022
2022
2022
2022
Consumer spray products release aerosols that can potentially be inhaled and reach the deep parts of the lungs. A thin layer of liquid, containing a mixture of proteins and lipids known as lung surfactant, coats the alveoli. Inhibition of lung surfactant function can lead to acute loss of lung function. We focused on two groups of spray products; 8 cleaning and 13 impregnation products, and in the context of risk assessment, used an in vitro method for assessing inhibition of lung surfactant function. Original spray-cans were used to generate aerosols to measure aerodynamic particle size distribution. We recreated a real-life exposure scenario to estimate the alveolar deposited dose. Most impregnation products inhibited lung surfactant function at the lowest aerosolization rate, whereas only two cleaning products inhibited function at the highest rates. We used inhibitory dose and estimated alveolar deposition to calculate the margin of safety (MoS). The MoS for the inhibitory products was ≤1 for the impregnation products, while much larger for the cleaning products (>880). This risk assessment focused on the risk of lung surfactant function disruption and provides knowledge on an endpoint of lung toxicity that is not investigated by the currently available OECD test guidelines.
2022
We describe the outcome of a large international interlaboratory study of the measurement of particle number concentration of colloidal nanoparticles, project 10 of the technical working area 34, “Nanoparticle Populations” of the Versailles Project on Advanced Materials and Standards (VAMAS). A total of 50 laboratories delivered results for the number concentration of 30 nm gold colloidal nanoparticles measured using particle tracking analysis (PTA), single particle inductively coupled plasma mass spectrometry (spICP-MS), ultraviolet-visible (UV-Vis) light spectroscopy, centrifugal liquid sedimentation (CLS) and small angle X-ray scattering (SAXS). The study provides quantitative data to evaluate the repeatability of these methods and their reproducibility in the measurement of number concentration of model nanoparticle systems following a common measurement protocol. We find that the population-averaging methods of SAXS, CLS and UV-Vis have high measurement repeatability and reproducibility, with between-labs variability of 2.6%, 11% and 1.4% respectively. However, results may be significantly biased for reasons including inaccurate material properties whose values are used to compute the number concentration. Particle-counting method results are less reproducibile than population-averaging methods, with measured between-labs variability of 68% and 46% for PTA and spICP-MS respectively. This study provides the stakeholder community with important comparative data to underpin measurement reproducibility and method validation for number concentration of nanoparticles.
2022
Revidert tiltaksutredning for lokal luftkvalitet i Bergen
Tiltaksutredningen for lokal luftkvalitet i Bergen med handlings- og beredskapsplan skal bidra til at forurensningsnivået holder seg innenfor kravene i forurensningsforskriften. Tiltaksutredningen omfatter en kartlegging av luftkvaliteten i Bergen kommune ved trafikkberegninger og utslipps- og spredningsberegninger for PM10, PM2,5 og NO 2 for Dagens situasjon 2019 og Referansesituasjonen 2030 med eksisterende og eventuelle nye tiltak. Utredningen vurderer effekten som tiltakene har for å overholde krav, men ser også på muligheten for ytterligere reduksjon i henhold til anbefalingene til helsemyndighetene. Basert på resultatene fra beregningene og i samarbeid med oppdragsgiver og referansegruppen, er det foreslått en revidert handlings- og beredskapsplan som skal behandles politisk.
NILU
2022
2022
Microplastics in Norwegian coastal areas, rivers, lakes and air (MIKRONOR1)
Norsk institutt for vannforskning
2022
Frontiers Media S.A.
2022
Northern Fulmars (Fulmarus glacialis) are a pelagic seabird species distributed at northern and polar latitudes. They are often used as an indicator of plastic pollution in the North Sea region, but data are lacking from higher latitudes, especially when it comes to chicks. Here, we investigated amounts of ingested plastic and their characteristics in fulmar chicks from the Faroe Islands. Plastic particles (1 mm) in chicks of two age classes were searched using a digestion method with KOH. In addition, to evaluate if additive tissue burden reflects plastic ingestion, we measured liver tissue concentrations of two pollutant classes associated with plastic materials: polybrominated diphenyl ethers (PBDEs) and several dechloranes, using gas chromatography with high-resolution mass spectrometry. The most common shape was hard fragment (81%) and the most common polymer was polyethylene (73%). Plastic contamination did not differ between either age class, and we found no correlation between neither the amount and mass of plastic particles and the concentration of additives. After comparison with previous studies on adult fulmars, we do not recommend using chicks for biomonitoring adults because chicks seem to ingest more plastics than adults.
2022
State of the Climate in 2021: 5. The Arctic
American Meteorological Society
2022
2022
VKM has performed a risk-benefit assessment of sunscreen use and six UV filters. This task
was undertaken on the initiative of a VKM Panel in response to the apparent paradox
between the need for protective measures, such as use of sunscreens, to reduce Norway’s
high incidence and mortality of skin cancer and a consumer concern for the safety of
sunscreens. Concerns include safety of ingredients and sunscreens’ effect on vitamin D
synthesis. Sunscreen products are legally regulated as cosmetic products in the EU, and only
approved UV filters up to a maximum determined concentration are allowed in the ready-foruse preparation.
VKM used a systematic approach to assess risks and benefits of sunscreen use and risks of
six selected UV filters: bis-ethyl-hexyloxyphenol methoxyphenyl triazine (BEMT), butyl
methoxydibenzoyl methane (BMDBM), 2-ethylhexyl salicylate (EHS), ethylhexyl triazone
(EHT), octocrylene (OC), and titanium dioxide in nanoform (NP-TiO2). These UV filters are
among the most frequently used in sunscreens on the Norwegian market. Sunscreen sprays
and lip products were not included. Scientific publications and reports up to 2020 were
retrieved to assess adverse and protective effects of sunscreen and adverse effects of UV
filters. We assessed risk of bias in the studies and evidence for health outcomes with the aid
of validity tools, and estimated exposure to each UV filter using probabilistic methods.
The evidence showed that sunscreens were beneficial in protecting against certain skin
cancers. Insufficient evidence precluded determination of the hazard associated with
sunscreen use.
The UV filters occurred in concentrations similar to or below the limits set in the EU
cosmetics regulative. VKM considered that little to no hazard was associated with use of the
six evaluated UV filters.
VKM concludes that the risks related to use of the six evaluated UV filters are negligible since
the real-life use of these UV filters is several-fold lower than the amounts that may cause
any adverse health effect. The evidence for harmful health effects of sunscreens is
insufficient to determine risk. Sunscreen use protects against certain skin cancers and is
beneficial for the general Norwegian population.
2022
2022
2021
The effect of the 2018 extreme meteorological conditions in Europe on methane (CH4) emissions is examined using estimates from four atmospheric inversions calculated for the period 2005–2018. For most of Europe, we find no anomaly in 2018 compared to the 2005–2018 mean. However, we find a positive anomaly for the Netherlands in April, which coincided with positive temperature and soil moisture anomalies suggesting an increase in biogenic sources. We also find a negative anomaly for the Netherlands for September–October, which coincided with a negative anomaly in soil moisture, suggesting a decrease in soil sources. In addition, we find a positive anomaly for Serbia in spring, summer and autumn, which coincided with increases in temperature and soil moisture, again suggestive of changes in biogenic sources, and the annual emission for 2018 was 33 ± 38% higher than the 2005–2017 mean. These results indicate that CH4 emissions from areas where the natural source is thought to be relatively small can still vary due to meteorological conditions. At the European scale though, the degree of variability over 2005–2018 was small, and there was negligible impact on the annual CH4 emissions in 2018 despite the extreme meteorological conditions.
This article is part of a discussion meeting issue ‘Rising methane: is warming feeding warming? (part 2)’.
2021
Aerosol particles are a complex component of the atmospheric system which influence climate directly by interacting with solar radiation, and indirectly by contributing to cloud formation. The variety of their sources, as well as the multiple transformations they may undergo during their transport (including wet and dry deposition), result in significant spatial and temporal variability of their properties. Documenting this variability is essential to provide a proper representation of aerosols and cloud condensation nuclei (CCN) in climate models. Using measurements conducted in 2016 or 2017 at 62 ground-based stations around the world, this study provides the most up-to-date picture of the spatial distribution of particle number concentration (Ntot) and number size distribution (PNSD, from 39 sites). A sensitivity study was first performed to assess the impact of data availability on Ntot's annual and seasonal statistics, as well as on the analysis of its diel cycle. Thresholds of 50 % and 60 % were set at the seasonal and annual scale, respectively, for the study of the corresponding statistics, and a slightly higher coverage (75 %) was required to document the diel cycle.
Although some observations are common to a majority of sites, the variety of environments characterizing these stations made it possible to highlight contrasting findings, which, among other factors, seem to be significantly related to the level of anthropogenic influence. The concentrations measured at polar sites are the lowest (∼ 102 cm−3) and show a clear seasonality, which is also visible in the shape of the PNSD, while diel cycles are in general less evident, due notably to the absence of a regular day–night cycle in some seasons. In contrast, the concentrations characteristic of urban environments are the highest (∼ 103–104 cm−3) and do not show pronounced seasonal variations, whereas diel cycles tend to be very regular over the year at these stations. The remaining sites, including mountain and non-urban continental and coastal stations, do not exhibit as obvious common behaviour as polar and urban sites and display, on average, intermediate Ntot (∼ 102–103 cm−3). Particle concentrations measured at mountain sites, however, are generally lower compared to nearby lowland sites, and tend to exhibit somewhat more pronounced seasonal variations as a likely result of the strong impact of the atmospheric boundary layer (ABL) influence in connection with the topography of the sites. ABL dynamics also likely contribute to the diel cycle of Ntot observed at these stations. Based on available PNSD measurements, CCN-sized particles (considered here as either >50 nm or >100 nm) can represent from a few percent to almost all of Ntot, corresponding to seasonal medians on the order of ∼ 10 to 1000 cm−3, with seasonal patterns and a hierarchy of the site types broadly similar to those observed for Ntot.
Overall, this work illustrates the importance of in situ measurements, in particular for the study of aerosol physical properties, and thus strongly supports the development of a broad global network of near surface observatories to increase and homogenize the spatial coverage of the measurements, and guarantee as well data availability and quality. The results of this study also provide a valuable, freely available and easy to use support for model comparison and validation, with the ultimate goal of contributing to improvement of the representation of aerosol–cloud interactions in models, and, therefore, of the evaluation of the impact of aerosol particles on climate.
2021
Beregning av luftkvalitet ved Bjørnheimveien 26
NILU har blitt engasjert av Prem Partners II A/S for å vurdere utbredelse av luftsoner for dagens situasjon og en framtidig situasjon med foreslått boligblokk i Bjørnheimveien 26. Det er anvendt en Gaussisk spredningsmodell for linjekilder (Hiway-2). Når det tas hensyn til at E6 går på bru ved det aktuelle området, viser beregningene et vesentlig lavere konsentrasjonsnivå og dermed mindre utbredelse av rød og gul luftsone på bakkenivå. Videre viser beregningene at skjermingseffekten for eksisterende bebyggelse av en ny bygning er marginal. Dersom de samme forutsetningene om høyde av veg og høyde av terreng legges til grunn, viser beregningene god overenstemmelse med eksisterende luftsonekart.
NILU
2021
Changes in black carbon emissions over Europe due to COVID-19 lockdowns
Following the emergence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) responsible for COVID-19 in December 2019 in Wuhan (China) and its spread to the rest of the world, the World Health Organization declared a global pandemic in March 2020. Without effective treatment in the initial pandemic phase, social distancing and mandatory quarantines were introduced as the only available preventative measure. In contrast to the detrimental societal impacts, air quality improved in all countries in which strict lockdowns were applied, due to lower pollutant emissions. Here we investigate the effects of the COVID-19 lockdowns in Europe on ambient black carbon (BC), which affects climate and damages health, using in situ observations from 17 European stations in a Bayesian inversion framework. BC emissions declined by 23 kt in Europe (20 % in Italy, 40 % in Germany, 34 % in Spain, 22 % in France) during lockdowns compared to the same period in the previous 5 years, which is partially attributed to COVID-19 measures. BC temporal variation in the countries enduring the most drastic restrictions showed the most distinct lockdown impacts. Increased particle light absorption in the beginning of the lockdown, confirmed by assimilated satellite and remote sensing data, suggests residential combustion was the dominant BC source. Accordingly, in central and Eastern Europe, which experienced lower than average temperatures, BC was elevated compared to the previous 5 years. Nevertheless, an average decrease of 11 % was seen for the whole of Europe compared to the start of the lockdown period, with the highest peaks in France (42 %), Germany (21 %), UK (13 %), Spain (11 %) and Italy (8 %). Such a decrease was not seen in the previous years, which also confirms the impact of COVID-19 on the European emissions of BC.
2021
This report presents a review of data assimilation methods applicable to air quality. In the introduction, we first describe a brief history of data assimilation method development in the context of numerical weather prediction (NWP), and then we highlight key differences when applying data assimilation methods to air quality prediction from NWP applications. Based on these differences, we outline a set of key requirements for data assimilation when applied to air quality. Following this, we review the available data assimilation algorithms and attempt to identify suitable data assimilation methods that could be applied with air quality models. This review and its findings form the basis of the developments to be carried out in the Urban Data Assimilation Systems project.
NILU
2021
NILU – Norsk institutt for luftforskning og Ingenia AS har på oppdrag fra Statens vegvesen kartlagt effekten ventilasjonstårnene i Ekeberg- og Bjørvikatunnelen har med hensyn til å redusere luftforurensning fra dagsonen på Sørenga. Prosjektet besto av et omfangsrikt måleprogram i og rundt Operatunnelen i Bjørvika, en vurdering av ventilasjonstårnenes effekt basert på målingene og forslag til prinsipper for et nytt styringsregime.
Drift av ventilasjonstårnene ble funnet å ha en tydelig effekt på PM10- og NO2-konsentrasjonen i dagsonen og på bakkenivå utenfor dagsonen fra trinn 3 (av 4). Forslaget til nytt styringsregime fokuserer på ventilasjonstårndrift i piggdekksesongen og avhengighet av ytre forhold.
NILU
2021
10-year satellite-constrained fluxes of ammonia improve performance of chemistry transport models
In recent years, ammonia emissions have been continuously increasing, being almost 4 times higher than in the 20th century. Although an important species, as its use as a fertilizer sustains human living, ammonia has major consequences for both humans and the environment because of its reactive gas-phase chemistry that makes it easily convertible to particles. Despite its pronounced importance, ammonia emissions are highly uncertain in most emission inventories. However, the great development of satellite remote sensing nowadays provides the opportunity for more targeted research on constraining ammonia emissions. Here, we used satellite measurements to calculate global ammonia emissions over the period 2008–2017. Then, the calculated ammonia emissions were fed to a chemistry transport model, and ammonia concentrations were simulated for the period 2008–2017.
The simulated concentrations of ammonia were compared with ground measurements from Europe, North America and Southeastern Asia, as well as with satellite measurements. The satellite-constrained ammonia emissions represent global concentrations more accurately than state-of-the-art emissions. Calculated fluxes in the North China Plain were seen to be more increased after 2015, which is not due to emission changes but due to changes in sulfate emissions that resulted in less ammonia neutralization and hence in larger atmospheric loads. Emissions over Europe were also twice as much as those in traditional datasets with dominant sources being industrial and agricultural applications. Four hot-spot regions of high ammonia emissions were seen in North America, which are characterized by high agricultural activity, such as animal breeding, animal farms and agricultural practices. South America is dominated by ammonia emissions from biomass burning, which causes a strong seasonality. In Southeastern Asia, ammonia emissions from fertilizer plants in China, Pakistan, India and Indonesia are the most important, while a strong seasonality was observed with a spring and late summer peak due to rice and wheat cultivation. Measurements of ammonia surface concentrations were better reproduced with satellite-constrained emissions, such as measurements from CrIS (Cross-track Infrared Sounder).
2021