Found 9746 publications. Showing page 49 of 390:
To assess how climate-sensitive factors may affect the exposure to organochlorines (OCs) and perfluoroalkyl substances (PFASs), we monitored concentrations in eggs of the common goldeneye (Bucephala clangula) over two decades (1999–2019) in central Norway. The goldeneye alternates between marine and freshwater habitats and is sensitive to climate variation, especially due to alterations in ice conditions which may affect feeding conditions. We assessed how biological factors such as diet (stable isotopes δ13C and δ15N), the onset of egg laying, and physical characteristics such as winter climate (North Atlantic Oscillation: NAOw) influenced exposure. We predicted compounds to show different temporal trends depending on whether they were still in production (i.e. some PFASs) or have been banned (i.e. legacy OCs and some PFASs). Therefore, we controlled for potential temporal trends in all analyses. There were declining trends for α- and γ-hexachlorocyclohexane (HCH), oxychlordane, cis-chlordane, cis-nonachlor, p,p′-dichlorodiphenyltrichloroethane (p.p′-DDT) and less persistent polychlorinated biphenyl (PCB) congeners (e.g. PCB101). In contrast, the dominant compounds, such as p,p′-dichlorodiphenyldichloroethylene (p,p′-DDE) and persistent PCB congeners, were stable, whereas hexachlorobenzene (HCB) increased over time. Most OCs were positively related to δ15N, suggesting higher exposure in birds feeding at upper trophic levels. Chlordanes and HCB were positively associated with δ13C, indicating traces of marine input for these compounds, whereas the relationships to most PCBs were negative. Among PFASs, perfluorooctanesulfonamide (PFOSA) and perfluorohexane sulfonic acid (PFHxS) declined. Most PFASs were positively associated with δ13C, whereas there were no associations with δ15N. Egg laying date was positively associated to perfluoroheptanesulfonic acid (PFHpS), perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), suggesting that some of the PFAS load originated from the wintering locations. Although NAOw had little impact on the exposure to organohalogenated contaminants, factors sensitive to climate change, especially diet, were associated with the exposure to OHCs in goldeneyes.
Elsevier
2022
Do cytotoxicity and cell death cause false positive results in the in vitro comet assay?
The comet assay is used to measure DNA damage induced by chemical and physical agents. High concentrations of test agents may cause cytotoxicity or cell death, which may give rise to false positive results in the comet assay. Systematic studies on genotoxins and cytotoxins (i.e. non-genotoxic poisons) have attempted to establish a threshold of cytotoxicity or cell death by which DNA damage results measured by the comet assay could be regarded as a false positive result. Thresholds of cytotoxicity/cell death range from 20% to 50% in various publications. Curiously, a survey of the latest literature on comet assay results from cell culture studies suggests that one-third of publications did not assess cytotoxicity or cell death. We recommend that it should be mandatory to include results from at least one type of assay on cytotoxicity, cell death or cell proliferation in publications on comet assay results. A combination of cytotoxicity (or cell death) and proliferation (or colony forming efficiency assay) is preferable in actively proliferating cells because it covers more mechanisms of action. Applying a general threshold of cytotoxicity/cell death to all types of agents may not be applicable; however, 25% compared to the concurrent negative control seems to be a good starting value to avoid false positive comet assay results. Further research is needed to establish a threshold value to distinguish between true and potentially false positive genotoxic effects detected by the comet assay.
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
Målinger av miljøgifter i luft ved Franzefoss Eide på Sotra og Husøya ved Kristiansund
NILU har gjennomført måleprogram for konsentrasjoner i luft ved Franzefoss Gjenvinning AS sine anlegg ved Eide på Sotra og ved Husøya ved Kristiansund. Ved Eide ble det tatt prøver i luft og analysert for prioriterte miljøgifter som dekloraner, fenoler, ftalater, PFAS, benzotriazoler, organiske tinnforbindelser, samt VOC inkludert D6, ammoniakk (NH3), gassfase HCl og hydrogensulfid (H2S). For de prioriterte miljøgiftene var de fleste prøvene under deteksjonsgrensen. De høyeste verdiene ble observert ved Lokasjon 11 Vannrenseanlegget. Ved Husøya ble det tatt prøver i luft og analysert for VOC inkludert D6, ammoniakk (NH3) og gassfase HCl. Verdiene ved Husøya var lavere enn ved Eide.
NILU
2022
A multi-pollutant and multi-sectorial approach to screening the consistency of emission inventories
Some studies show that significant uncertainties affect emission inventories, which may impeach conclusions based on air-quality model results. These uncertainties result from the need to compile a wide variety of information to estimate an emission inventory. In this work, we propose and discuss a screening method to compare two emission inventories, with the overall goal of improving the quality of emission inventories by feeding back the results of the screening to inventory compilers who can check the inconsistencies found and, where applicable, resolve errors. The method targets three different aspects: (1) the total emissions assigned to a series of large geographical areas, countries in our application; (2) the way these country total emissions are shared in terms of sector of activity; and (3) the way inventories spatially distribute emissions from countries to smaller areas, cities in our application. The first step of the screening approach consists of sorting the data and keeping only emission contributions that are relevant enough. In a second step, the method identifies, among those significant differences, the most important ones that provide evidence of methodological divergence and/or errors that can be found and resolved in at least one of the inventories. The approach has been used to compare two versions of the CAMS-REG European-scale inventory over 150 cities in Europe for selected activity sectors. Among the 4500 screened pollutant sectors, about 450 were kept as relevant, among which 46 showed inconsistencies. The analysis indicated that these inconsistencies arose almost equally from large-scale reporting and spatial distribution differences. They mostly affect SO2 and PM coarse emissions from the industrial and residential sectors. The screening approach is general and can be used for other types of applications related to emission inventories.
2022
South Africa is the largest national source of industrial atmospheric pollutants in Africa, and the emission of acid-forming pollutants occurs mainly in the eastern Highveld region of the country. However, spatial information on deposition is very sparse beyond the primary emissions zone. Here we quantify wet and dry deposition at four sites from the far northern savanna (Vaalwater) through the grasslands of the interior coal-producing belt of Mpumalanga (Elandsfontein) and the remote KwaZulu Natal Drakensberg mountains (Cathedral Peak) to the fynbos of the southern coast of the country (Knysna), a distance of over 1200 km. Rainwater samples were collected using automated wet-only samplers and analysed for mineral ions and water-soluble organic acids. Wet deposition fluxes were driven largely by rainfall amount rather than differences in chemical composition for three inland sites, with the highest wet deposited sulphur (S) (5.1 kgS/ha/year) and nitrogen (N) (6.9 kgN/ha/year) found in the Drakensberg mountains, greatly expanding the potentially harmful deposition footprint beyond the industrialised Highveld zone. Furthermore, the study period covered the extreme drought years of 2015–2016; hence, wet deposition fluxes could be significantly underestimated relative to more average rainfall years. Dry deposition fluxes, estimated using passive samplers and inferential methods, were far higher at the industrial Highveld site. Overall, total (wet + dry) deposition of S was greatest at the Highveld site (12.0 kgS/ha/year), but the greatest total N deposition (7.0 kgN/ha/year) was found at the remote Drakensberg site. Measured levels of both S and N deposition are well within the ranges found to cause acidification of soils and surface waters in northern hemisphere studies, or changes in vegetation species composition, and could be much higher in more typical, wetter years.
2022
Emission inventories indicate that thallium, a highly toxic metal, is emitted during coal burning and cement production. These estimates have been established only for the 1980s and 1990s but up to now they have not been compared to long-term observations. Here we used alpine ice cores to document thallium pollution over Europe since ∼1850. Ice-core thallium concentrations increased from 1890 to 1910, and decreased after 1965 to concentrations that were half 1890 levels. Comparison of ice-core trends, estimated past emissions, and state-of-the-art atmospheric aerosol transport modeling suggest that coal burning was responsible for thallium pollution in Europe, particularly from 1920 to 1965 because of high coal consumption at that time. The subsequent decline resulted from decreased coal consumption and reduced emissions following technological improvements. The ice-core data suggest that the rapid growth of cement production that took place in Europe after 1950 had a limited impact on thallium pollution.
American Geophysical Union (AGU)
2022
2022
Health impacts of PM
Residential wood combustion (RWC) is one of the largest sources of fine particles (PM2.5) in the Nordic cities. The current study aims to calculate the related health effects in four studied city areas in Sweden, Finland, Norway, and Denmark.
BioMed Central (BMC)
2022
Målinger av SO2 i omgivelsene til Elkem Carbon og REC Solar. Januar 2021 – desember 2021.
På oppdrag fra Elkem Carbon AS har NILU utført målinger av SO2 i omgivelsene til Elkem Carbon og REC Solar i Vågsbygd (Kristiansand kommune). Elkem Carbon har i sin tillatelse fra Miljødirektoratet krav om å gjennomføre kontinuerlig måling av SO2 i omgivelsesluft. Målingene ble utført med SO2-monitor i boligområdet på Fiskåtangen (Konsul Wilds vei). I tillegg har Elkem Carbon AS valgt å måle med passive SO2-prøvetakere ved 3 steder rundt bedriftene. Rapporten dekker målinger i perioden 1. januar – 31. desember 2021. Norske grenseverdier for luftkvalitet (SO2) ble overholdt ved Konsul Wilds vei for alle midlingsperioder krevet i forurensningsforskriften (årsmiddel, vintermiddel, døgnmiddel og timemiddel). De mest belastede stedene i måleperioden var Konsul Wilds vei nordøst og Fiskåveien rett sør for bedriftene. To døgnmidler var over 125 µg/m3 (grenseverdi, 3 tillatt), 16 døgnmidler var over øvre vurderingsterskel (75 µg/m3) og 33 døgnmidler var over nedre vurderingsterskel (50 µg/m3).
NILU
2022
2022
2022
Beregning av korrosjonsklasse fra miljøparametere i Fitjar. Lokasjon (59°56’11.5″N 5°19’58.4″Ø)
Korrosjonsklasse ble beregnet på lokasjon (59°56'11.5"N 5°19'58.4"Ø) i Fitjar, Vestland, Norge, fra årsgjennomsnitt for miljøparametere etter ISO 9223 og ISO 12944-2. Det ble funnet at korrosjonsklassen med høy sannsynlighet er C3 og at dette i hovedsak er bestemt av våt-tiden på omtrent 4500 timer/år, som gjennomsnitt i perioden 2007-2022. Dette er godt innenfor grensene for C3 når saltavsetningen er < 60 mg Cl-/m2døgn og SO2 konsentrasjonen i luft < 30 µg/m3. Disse betingelsene synes med stor sannsynlighet oppfylt på lokasjonen i Fitjar som årsgjennomsnitt i normalår.
NILU
2022
2022
Potential environmental impact of bromoform from Asparagopsis farming in Australia
To mitigate the rumen enteric methane (CH4) produced by ruminant livestock, Asparagopsis taxiformis is proposed as an additive to ruminant feed. During the cultivation of Asparagopsis taxiformis in the sea or in terrestrially based systems, this macroalgae, like most seaweeds and phytoplankton, produces a large amount of bromoform (CHBr3), which contributes to ozone depletion once released into the atmosphere. In this study, we focus on the impact of CHBr3 on the stratospheric ozone layer resulting from potential emissions from proposed Asparagopsis cultivation in Australia. The impact is assessed by weighting the emissions of CHBr3 with its ozone depletion potential (ODP), which is traditionally defined for long-lived halocarbons but has also been applied to very short-lived substances (VSLSs). An annual yield of ∼3.5 × 104 Mg dry weight is required to meet the needs of 50 % of the beef feedlot and dairy cattle in Australia. Our study shows that the intensity and impact of CHBr3 emissions vary, depending on location and cultivation scenarios. Of the proposed locations, tropical farms near the Darwin region are associated with the largest CHBr3 ODP values. However, farming of Asparagopsis using either ocean or terrestrial cultivation systems at any of the proposed locations does not have the potential to significantly impact the ozone layer. Even if all Asparagopsis farming were performed in Darwin, the CHBr3 emitted into the atmosphere would amount to less than 0.02 % of the global ODP-weighted emissions. The impact of remaining farming scenarios is also relatively small even if the intended annual yield in Darwin is scaled by a factor of 30 to meet the global requirements, which will increase the global ODP-weighted emissions up to ∼0.5 %.
2022
2022
Publications Office of the European Union
2022
2022
2022
Carbon felts are flexible and scalable, have high specific areas, and are highly conductive materials that fit the requirements for both anodes and cathodes in advanced electrocatalytic processes. Advanced oxidative modification processes (thermal, chemical, and plasma-chemical) were applied to carbon felt anodes to enhance their efficiency towards electro-oxidation. The modification of the porous anodes results in increased kinetics of acetaminophen degradation in aqueous environments. The utilised oxidation techniques deliver single-step, straightforward, eco-friendly, and stable physiochemical reformation of carbon felt surfaces. The modifications caused minor changes in both the specific surface area and total pore volume corresponding with the surface morphology.
A pristine carbon felt electrode was capable of decomposing up to 70% of the acetaminophen in a 240 min electrolysis process, while the oxygen-plasma treated electrode achieved a removal yield of 99.9% estimated utilising HPLC-UV-Vis. Here, the electro-induced incineration kinetics of acetaminophen resulted in a rate constant of 1.54 h−1, with the second-best result of 0.59 h−1 after oxidation in 30% H2O2. The kinetics of acetaminophen removal was synergistically studied by spectroscopic and electrochemical techniques, revealing various reaction pathways attributed to the formation of intermediate compounds such as p-aminophenol and others.
The enhancement of the electrochemical oxidation rates towards acetaminophen was attributed to the appearance of surface carbonyl species. Our results indicate that the best-performing plasma-chemical treated CFE follows a heterogeneous mechanism with only approx. 40% removal due to direct electro-oxidation. The degradation mechanism of acetaminophen at the treated carbon felt anodes was proposed based on the detected intermediate products. Estimation of the cost-effectiveness of removal processes, in terms of energy consumption, was also elaborated. Although the study was focussed on acetaminophen, the achieved results could be adapted to also process emerging, hazardous pollutant groups such as anti-inflammatory pharmaceuticals.
Pergamon Press
2022
Thymidine Kinase+/− Mammalian Cell Mutagenicity Assays for Assessment of Nanomaterials
The methods outlined here are part of a series of papers designed specifically for genotoxicity assessment of nanomaterials (NM). Common Considerations such as NM characterization, sample preparation and dose selection, relevant to all genotoxicity assays, are found in an accompanying paper. The present paper describes methods for evaluation of mutagenicity in the mammalian (mouse) thymidine kinase (Tk) gene occurring in L5178Y mouse lymphoma (ML) cells and in the designated TK gene in human lymphoblastoid TK6 cells. Mutations change the functional genotype from TK+/− to TK−/−, detectable as cells surviving on media selective for the lack of thymidine kinase (TK) function. Unlike cells with TK enzyme function, the TK−/− cells are unable to integrate the toxic selection agent, allowing these cells to survive as rare mutant colonies. The ML assay has been shown to detect a broad spectrum of genetic damage, including both small scale (point) mutations and chromosomal alterations. This assay is a widely used mammalian cell gene mutation assay for regulatory purposes and is included in the core battery of genotoxicity tests for regulatory decision-making. The TK6 assay is an assay using a human cell line derived similarly via mutagenic manipulations and optimal selection. Details are provided on the materials required, cell culture methods, selection of test chemical concentrations, cytotoxicity, treatment time, mutation expression, cloning, and data calculation and interpretation. The methods describe the microwell plate version of the assays without metabolic activation.
Frontiers Media S.A.
2022