| 1. |
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| 2. |
- Cappellini, Francesca, et al.
(författare)
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Dry Generation of CeO2 Nanoparticles and Deposition onto a Co-Culture of A549 and THP-1 Cells in Air-Liquid Interface-Dosimetry Considerations and Comparison to Submerged Exposure
- 2020
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Ingår i: Nanomaterials. - : MDPI AG. - 2079-4991. ; 10:4
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Tidskriftsartikel (refereegranskat)abstract
- Relevant in vitro assays that can simulate exposure to nanoparticles (NPs) via inhalation are urgently needed. Presently, the most common method employed is to expose lung cells under submerged conditions, but the cellular responses to NPs under such conditions might differ from those observed at the more physiological air-liquid interface (ALI). The aim of this study was to investigate the cytotoxic and inflammatory potential of CeO2 NPs (NM-212) in a co-culture of A549 lung epithelial cells and differentiated THP-1 cells in both ALI and submerged conditions. Cellular dose was examined quantitatively using inductively coupled plasma mass spectrometry (ICP-MS). The role of serum and LPS-priming for IL-1 beta release was further tested in THP-1 cells in submerged exposure. An aerosol of CeO2 NPs was generated by using the PreciseInhale (R) system, and NPs were deposited on the co-culture using XposeALI (R). No or minor cytotoxicity and no increased release of inflammatory cytokines (IL-1 beta, IL-6, TNF alpha, MCP-1) were observed after exposure of the co-culture in ALI (max 5 mu g/cm(2)) or submerged (max 22 mu g/cm(2)) conditions. In contrast, CeO2 NPs cause clear IL-1 beta release in monocultures of macrophage-like THP-1, independent of the presence of serum and LPS-priming. This study demonstrates a useful approach for comparing effects at various in-vitro conditions.
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| 3. |
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| 4. |
- Cronholm, Pontus, et al.
(författare)
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Effect of sonication and serum proteins on copper release from copper nanoparticles and the toxicity towards lung epithelial cells
- 2011
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Ingår i: Nanotoxicology. - : Informa UK Limited. - 1743-5390 .- 1743-5404. ; 5:2, s. 269-281
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Tidskriftsartikel (refereegranskat)abstract
- Different methodological settings can influence particle characteristics and toxicity in nanotoxicology. The aim of this study was to investigate how serum proteins and sonication of Cu nanoparticle suspensions influence the properties of the nanoparticles and toxicological responses on human lung epithelial cells. This was investigated by using methods for particle characterization (photon correlation spectroscopy and TEM) and Cu release (atomic absorption spectroscopy) in combination with assays for analyzing cell toxicity (MTT-, trypan blue- and Comet assay). The results showed that sonication of Cu nanoparticles caused decreased cell viability and increased Cu release compared to non-sonicated particles. Furthermore, serum in the cell medium resulted in less particle agglomeration and increased Cu release compared with medium without serum, but no clear difference in toxicity was detected. Few cells showed intracellular Cu nanoparticles due to fast release/dissolution processes of Cu. In conclusion; sonication can affect the toxicity of nanoparticles.
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| 5. |
- Cronholm, Pontus, et al.
(författare)
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Intracellular Uptake and Toxicity of Ag and CuO Nanoparticles : A Comparison Between Nanoparticles and their Corresponding Metal Ions
- 2013
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Ingår i: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 9:7, s. 970-982
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Tidskriftsartikel (refereegranskat)abstract
- An increased understanding of nanoparticle toxicity and its impact on human health is essential to enable a safe use of nanoparticles in our society. The aim of this study is to investigate the role of a Trojan horse type mechanism for the toxicity of Ag-nano and CuO-nano particles and their corresponding metal ionic species (using CuCl2 and AgNO3), i.e., the importance of the solid particle to mediate cellular uptake and subsequent release of toxic species inside the cell. The human lung cell lines A549 and BEAS-2B are used and cell death/membrane integrity and DNA damage are investigated by means of trypan blue staining and the comet assay, respectively. Chemical analysis of the cellular dose of copper and silver is performed using atomic absorption spectroscopy. Furthermore, transmission electron microscopy, laser scanning confocal microscopy, and confocal Raman microscopy are employed to study cellular uptake and particle-cell interactions. The results confirm a high uptake of CuO-nano and Ag-nano compared to no, or low, uptake of the soluble salts. CuO-nano induces both cell death and DNA damage whereas CuCl2 induces no toxicity. The opposite is observed for silver, where Ag-nano does not cause any toxicity, whereas AgNO3 induces a high level of cell death. In conclusion: CuO-nano toxicity is predominantly mediated by intracellular uptake and subsequent release of copper ions, whereas no toxicity is observed for Ag-nano due to low release of silver ions within short time periods.
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| 6. |
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| 7. |
- Elihn, Karine, et al.
(författare)
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Air quality impacts of a large waste fire in Stockholm, Sweden
- 2023
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 315
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Tidskriftsartikel (refereegranskat)abstract
- Fires in waste facilities are a common occurrence. Since many waste facilities are located adjacent to densely populated areas, these fires could potentially expose large populations to the emitted pollutants. However, at the moment there are only few field studies investigating the impact of waste fire emissions on air quality since the unpredictable nature of these events makes them challenging to capture. This study investigated the impact of a large and persistent un-prescribed fire in a waste storage facility in Stockholm county, Sweden, on the local air quality of two residential areas in close proximity to the fire. In-situ measurements of particulate matter, black carbon and nitrogen oxide concentrations were conducted both during open burning and after the fire was fully covered. In addition, filter samples were collected for offline analysis of organic composition, metal content and toxicity. Strongly increased concentrations of PM10, PM2.5 and black carbon were found during the open burning period, especially when the wind was coming from the direction of the fire. In addition, elevated concentrations of particulate heavy metals and polycyclic aromatic hydrocarbons were observed in the air during the open burning period. These results show that waste fires can have a strong impact on the air quality of nearby residential areas.
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| 8. |
- Elihn, Karine, et al.
(författare)
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Cellular Dose of Partly Soluble Cu Particle Aerosols at the Air-Liquid Interface Using an In Vitro Lung Cell Exposure System
- 2013
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Ingår i: Journal of Aerosol Medicine. - : Mary Ann Liebert Inc. - 1941-2711 .- 1941-2703. ; 26:2, s. 84-93
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Tidskriftsartikel (refereegranskat)abstract
- Background: There is currently a need to develop and test in vitro systems for predicting the toxicity of nanoparticles. One challenge is to determine the actual cellular dose of nanoparticles after exposure. Methods: In this study, human epithelial lung cells (A549) were exposed to airborne Cu particles at the air-liquid interface (ALI). The cellular dose was determined for two different particle sizes at different deposition conditions, including constant and pulsed Cu aerosol flow. Results: Airborne polydisperse particles with a geometric mean diameter (GMD) of 180nm [geometric standard deviation (GSD) 1.5, concentration 10(5) particles/mL] deposited at the ALI yielded a cellular dose of 0.4-2.6 mu g/cm(2) at pulsed flow and 1.6-7.6 mu g/cm(2) at constant flow. Smaller polydisperse particles in the nanoregime (GMD 80 nm, GSD 1.5, concentration 10(7) particles/mL) resulted in a lower cellular dose of 0.01-0.05 mu g/cm(2) at pulsed flow, whereas no deposition was observed at constant flow. Exposure experiments with and without cells showed that the Cu particles were partly dissolved upon deposition on cells and in contact with medium. Conclusions: Different cellular doses were obtained for the different Cu particle sizes (generated with different methods). Furthermore, the cellular doses were affected by the flow conditions in the cell exposure system and the solubility of Cu. The cellular doses of Cu presented here are the amount of Cu that remained on the cells after completion of an experiment. As Cu particles were partly dissolved, Cu (a nonnegligible contribution) was, in addition, present and analyzed in the nourishing medium present beneath the cells. This study presents cellular doses induced by Cu particles and demonstrates difficulties with deposition of nanoparticles at the ALI and of partially soluble particles.
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| 9. |
- Elihn, Karine, et al.
(författare)
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Correlation between airborne particle concentrations in seven industrial plants and estimated respiratory tract deposition by number, mass and elemental composition
- 2011
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Ingår i: Journal of Aerosol Science. - : Elsevier BV. - 0021-8502 .- 1879-1964. ; 42:2, s. 127-141
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Tidskriftsartikel (refereegranskat)abstract
- The number and mass distribution of airborne particles were recorded in several industrial plants. From the data obtained, particle deposition was estimated in three regions of the respiratory tract using the ICRP grand average deposition model based on Hinds' (1999) parameterization. The median diameter was 30-70 nm (number distributions), and >4 mu m (mass distributions) near most work activities, resulting in linear relationships between the deposited number/mass concentrations and the number/mass concentrations in the air. Welding and laser cutting produced particles in the 200-500-nm range; total deposition was small, not in accordance with the linear relationship observed for the other work activities. The elemental content varied between particle sizes in some workplaces, causing different elements to deposit in different respiratory regions. Iron was the most abundant element in the particles in many of the workplaces; in an iron foundry, however, Fe was most abundant only in the micron-sized particles whereas the nanoparticles mainly comprised Pb and Sb.
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| 10. |
- Elihn, Karine, et al.
(författare)
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Exposure to Ultrafine Particles in Asphalt Work
- 2008
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Ingår i: Journal of Occupational and Environmental Hygiene. - : Informa UK Limited. - 1545-9624 .- 1545-9632. ; 5, s. 771-779
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Tidskriftsartikel (refereegranskat)
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| 11. |
- Elihn, Karine, et al.
(författare)
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Size and structure of nanoparticles formed via ultraviolet photolysis of ferrocene
- 2007
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 101:3, s. 034311-
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Tidskriftsartikel (refereegranskat)abstract
- Iron nanoparticles enclosed in carbon shells were formed by laser-assisted chemical vapor decomposition of ferrocene (Fe(C5H5)2) vapor in Ar gas atmosphere. The particle size dependence on the total ambient gas pressure and on laser fluence of the pulsed ArF excimer laser was examined and, e.g., an effective size decrease of the iron core was observed at elevated laser fluences. Characterizations of the iron and carbon microstructures were performed by x-ray diffraction and transmission electron microscopy, while relative iron deposition rates were measured by x-ray fluorescence spectroscopy. Both -Fe and -Fe phases were found for the single crystalline iron cores, surrounded by graphitic (inner) and amorphous (outer) carbon layers. The temperature rise of the laser-excited particles was also determined by optical spectroscopy of the emitted thermal radiation, which allowed an estimation of the iron loss of the nanoparticles due to evaporation. The estimated and measured iron losses are in good agreement.
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| 12. |
- Elihn, Karine, 1971-
(författare)
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Synthesis of carbon-covered iron nanoparticles by photolysis of ferrocene
- 2002
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- One important driving force in nanotechnology today is the change which can be made in the properties of a material when the dimensions of its individual building blocks are decreased below approximately 100 nm. Such small building blocks, typically nanoparticles, may induce new and unique properties compared to those of the corresponding bulk material. The challenge in nanotechnology is to make nanoparticles with a discrete particle size within the range 1-10 nm. It is also important to develop appropriate assembly methodologies in order to construct devices composed of such small building blocks.This thesis reports iron nanoparticle synthesis using laser-assisted photolysis of ferrocene. The particles were protected against oxidation by a carbon shell formed in situ during their growth. By varying the experimental conditions such as fluence, repetition rate and laser beam area, particles could be synthesized in the size range 1 to 100 nm. Their size was measured using a differential mobility analyser (DMA), transmission electron microscopy (TEM) and X-ray diffraction (XRD). DMA was also used successfully to size-select particles to facilitate the deposition of monodisperse nanoparticle films.A theoretical "residence time approach (RTA)" model was developed to relate particle volume to the laser parameters used. The growth of these particles was studied in situ using optical emission spectroscopy; the results were compared with those from quantum mechanical calculations. The particles were characterised ex situ by TEM, convergent beam electron diffraction, XRD, X-ray photoelectron spectroscopy and Raman spectroscopy. Results from the TEM investigations revealed that the carbon shell was graphitic close to the iron core, while the outer part of the carbon shell was amorphous, indicating different growth mechanisms. Both bcc and fcc iron particles were observed.
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| 13. |
- Elihn, Karine, et al.
(författare)
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Ultrafine particle characteristics in seven industrial plants.
- 2009
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Ingår i: Annals of Occupational Hygiene. - : Oxford University Press (OUP). - 0003-4878 .- 1475-3162. ; 53:5, s. 475-484
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Tidskriftsartikel (refereegranskat)abstract
- Ultrafine particles are considered as a possible cause of some of the adverse health effects caused by airborne particles. In this study, the particle characteristics were measured in seven Swedish industrial plants, with a special focus on the ultrafine particle fraction. Number concentration, size distribution, surface area concentration, and mass concentration were measured at 10 different job activities, including fettling, laser cutting, welding, smelting, core making, moulding, concreting, grinding, sieving powders, and washing machine goods. A thorough particle characterization is necessary in workplaces since it is not clear yet which choice of ultrafine particle metric is the best to measure in relation to health effects. Job activities were given a different order of rank depending on what particle metric was measured. An especially high number concentration (130 x 10(3) cm(-3)) and percentage of ultrafine particles (96%) were found at fettling of aluminium, whereas the highest surface area concentration (up to 3800 mum(2) cm(-3)) as well as high PM10 (up to 1 mg m(-3)) and PM1 (up to 0.8 mg m(-3)) were found at welding and laser cutting of steel. The smallest geometric mean diameter (22 nm) was found at core making (geometric standard deviation: 1.9).
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| 14. |
- Fromell, Karin, et al.
(författare)
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Nanoparticle decorated surfaces with potential use in glycosylation analysis
- 2005
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Ingår i: Colloids and Surfaces B: Biointerfaces. ; 46, s. 84–91-
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Tidskriftsartikel (refereegranskat)abstract
- A majority of all biologically active proteins are glycosylated and various diseases have proven to correlate with alterations in protein glycosylation. Sensitive identification of different glycoprotein glycoforms is therefore of great diagnostic value. Here we describe a method with potential for glycoprotein profiling, based on lectins as capture probes immobilized on particulate substrates in the nm-range. The nanoparticles present high concentrations of attachment sites for specific ligands and cause minimal steric hindrance to binding. In the present model study the mannose-binding lectin ConA has been coupled to polystyrene nanoparticles via a poly(ethyleneoxide) linker which protects the protein conformation and activity and prevents unspecific protein adsorption. The ConA-coated particles are accommodated at different spots on the analytical surface via oligonucleotide linkage. This attachment, which relies on the hybridization of complementary oligonucleotides, allows firm fixation of the particles at specific positions. The ConA attached to the particles has retained conformation and activity and binds selectively to a series of different glycoproteins. The results indicate the potential for using a multi-lectin nanoparticle array in glycoprotein mapping.
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| 15. |
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| 16. |
- Fromell, Karin, et al.
(författare)
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The effect of airborne Palladium nanoparticles on human lung cells, endothelium and blood-A combinatory approach using three in vitro models
- 2023
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Ingår i: Toxicology in Vitro. - : Elsevier. - 0887-2333 .- 1879-3177. ; 89
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Tidskriftsartikel (refereegranskat)abstract
- A better understanding of the mechanisms behind adverse health effects caused by airborne fine particles and nanoparticles (NP) is essential to improve risk assessment and identification the most critical particle exposures. While the use of automobile catalytic converters is decreasing the exhausts of harmful gases, concentrations of fine airborne particles and nanoparticles (NPs) from catalytic metals such as Palladium (Pd) are reaching their upper safe level. Here we used a combinatory approach with three in vitro model systems to study the toxicity of Pd particles, to infer their potential effects on human health upon inhalation. The three model systems are 1) a lung system with human lung cells (ALI), 2) an endothelial cell system and 3) a human whole blood loop system. All three model systems were exposed to the exact same type of Pd NPs. The ALI lung cell exposure system showed a clear reduction in cell growth from 24 h onwards and the effect persisted over a longer period of time. In the endothelial cell model, Pd NPs induced apoptosis, but not to the same extent as the most aggressive types of NPs such as TiO2. Similarly, Pd triggered clear coagulation and contact system activation but not as forcefully as the highly thrombogenic TiO2 NPs. In summary, we show that our 3-step in vitro model of the human lung and surrounding vessels can be a useful tool for studying pathological events triggered by airborne fine particles and NPs.
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| 17. |
- Hedberg, Yolanda, et al.
(författare)
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Surface passivity largely governs the bioaccessibility of nickel-based powder particles at human exposure conditions
- 2016
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Ingår i: Regulatory toxicology and pharmacology. - : Elsevier BV. - 0273-2300 .- 1096-0295. ; 81, s. 162-170
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Tidskriftsartikel (refereegranskat)abstract
- The European chemical framework REACH requires that hazards and risks posed by chemicals, including alloys and metals, are identified and proven safe for humans and the environment. Therefore, differences in bioaccessibility in terms of released metals in synthetic biological fluids (different pH (1.5-7.4) and composition) that are relevant for different human exposure routes (inhalation, ingestion, and dermal contact) have been assessed for powder particles of an alloy containing high levels of nickel (Inconel 718, 57 wt% nickel). This powder is compared with the bioaccessibility of two nickel-containing stainless steel powders (AISI 316L, 10-12% nickel) and with powders representing their main pure alloy constituents: two nickel metal powders (100% nickel), two iron metal powders and two chromium metal powders. Xray photoelectron spectroscopy, microscopy, light scattering, and nitrogen absorption were employed for the particle and surface oxide characterization. Atomic absorption spectroscopy was used to quantify released amounts of metals in solution. Cytotoxicity (Alamar blue assay) and DNA damage (comet assay) of the Inconel powder were assessed following exposure of the human lung cell line A549, as well as its ability to generate reactive oxygen species (DCFH-DA assay). Despite its high nickel content, the Inconel alloy powder did not release any significant amounts of metals and did not induce any toxic response. It is concluded, that this is related to the high surface passivity of the Inconel powder governed by its chromium-rich surface oxide. Read-across from the pure metal constituents is hence not recommended either for this or any other passive alloy.
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| 18. |
- Kotova, Natalia, et al.
(författare)
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Nätverk vid upptäckt av befolkningsexponering för farliga kemiska ämnen : en sammanställning av kompetens och laboratorieverksamhet bland regionala Arbets- och miljömedicinska enheter vid upptäckt av befolkningsexponering för farliga ämnen av kemiskt ursprung där livsmedel och dricksvatten kan vara en potentiell källa
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I Livsmedelsverkets beredskapsarbete ingår att göra uppskattningar av vilka nivåer av farliga ämnen som konsumenterna får i sig via livsmedel och att tidigt upptäcka exponering som kan resultera i skadliga hälsoeffekter. Detta arbete innebär att övervakningen behöver förbättras gällande risker för kemisk exponering. I händelse av kemisk exponering av befolkningen via livsmedel eller vatten, beroende på olyckor eller antagonistiska händelser, behövs en väl samordnad kedja inkluderande bl.a. operativa aktörer samt centrala och regionala myndigheter.Denna rapport är ett resultat av krisberedskapsprojektet Nätverk vid upptäckt av befolkningsexponering för farliga kemiska ämnen som finansierats med 2:4-anslag från MSB. Projektets syfte är att bilda ett nätverk mellan olika aktörer för att skapa förutsättningar för ett bättre utnyttjande av landets samlade kapacitet och kompetens avseende provtagnings- och laboratorieanalys i avsikt att identifiera farliga kemiska ämnen i prover från människa. Nätverket är till för att skapa en effektivare beredskap vid allvarliga händelser med kemiska ämnen och/eller för övervakning av exponering för kemiska ämnen hos den svenska befolkningen.Projektet fokuserade på att inventera och förbättra kunskapsläget och laboratorieberedskap för provtagning och analys av prover från människa vid upptäckt av befolkningsexponering för farliga ämnen. Detta gäller i livsmedel och dricksvatten då ämnen av kemiskt ursprung kan vara en potentiell farlig källa. Projektet skapade ett nätverk mellan myndigheter och regionala Arbets- och miljömedicinska (AMM) enheter för att skapa förutsättningar för ett bättre utnyttjande av landets samlade kapacitet, kompetens och laboratorier inom AMM-verksamheten. För att stärka såväl regional som nationell krisberedskap när det gäller hanteringen av oönskade händelser så har projektets alla AMM-enheter i Sverige kartlagt kompetens och laboratoriekapacitet samt testat förmågan att arbeta i fält med provtagning och efterhantering av prover.Målgruppen för rapporten är de som arbetar med identifiering och riskvärdering av farliga ämnen med kemiskt ursprung i befolkningen, både vid kris och i vardagen. Nätverkets arbete resulterade bl.a. i de manualer som används vid exponering för olika typer av CBRNE-ämnen dvs. inte enbart kemiska (C-ämnen), men också biologiska (B-ämnen), radiologiska (R-ämnen), nukleära (N-ämnen) och explosiva (E-ämnen). Projektet har drivits av Livsmedelsverket i ett nära samarbete med regionala AMM-enheter och Totalförsvarets Forskningsinstitut (FOI) samt i samverkan med Folkhälsomyndigheten, Naturvårdsverket, Socialstyrelsen, Kemikalieinspektionen och Karolinska Institutet.
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| 19. |
- Latvala, Siiri, 1987-
(författare)
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Development and comparison of in vitro toxicity methods for nanoparticles : Focus on lung cell exposure
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Concerns for the toxic effects of airborne nanoparticles have been raised along with the increasing production of nanostructured materials. However, the health risks of nanoparticle exposure are currently not fully understood. The most commonly used techniques to study nanoparticle toxicity, both in vivo and in vitro, have several limitations. These include for example challenges regarding dosimetry or the lack of similarity of overall exposure conditions and the physico-chemical particle characteristics. Therefore, there is a need for more advanced methods to study the pulmonary toxicity of airborne nanoparticles.This thesis presents the use of air-liquid interface (ALI) systems as a possible approach to this challenge. While utilizing the direct deposition of airborne nanoparticles on lung cell cultures, the ALI approach can more realistically mimic the characteristics of the human respiratory tract and the interactions of airborne particles with lung cells. This allows for a better understanding of the health risks posed by inhalation exposure to nanoparticles.Two different ALI systems were investigated and their use was compared to submerged exposure methods. One of the ALI exposure systems utilizes electrostatic force in order to make the deposition of charged airborne nanoparticles more efficient, while the other system operates by the diffusion of airborne nanoparticles. ALI and submerged exposure methods were used for investigating the cytotoxicity and genotoxicity of Ni-containing nanoparticles as well as the cytotoxicity and inflammatory potential of CeO2-nanoparticles. While Ag-nanoparticles were used as a test material during the development of the electrostatic ALI system, their cytotoxicity was investigated in ALI exposure. In conclusion, the ALI exposure methods provide more realistic conditions and make the particle dosimetry more controllable.
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| 20. |
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| 21. |
- Latvala, Siiri, et al.
(författare)
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In vitro genotoxicity of airborne Ni-NP in air-liquid interface
- 2017
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Ingår i: Journal of Applied Toxicology. - : Wiley. - 0260-437X .- 1099-1263. ; 37:12, s. 1420-1427
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Tidskriftsartikel (refereegranskat)abstract
- Studies using advanced toxicological methods enabling in vitro conditions that are more realistic are currently needed for understanding the risks of pulmonary exposure to airborne nanoparticles. Owing to the carcinogenicity of certain nickel compounds, the increased production of nickel nanoparticles (Ni-NPs) raises occupational safety concerns. The aim of this study was to investigate the genotoxicity of airborne Ni-NPs using a recently developed air-liquid interface exposure system. The wild-type Chinese hamster lung fibroblast cell line (V79) was used and cytotoxicity, DNA damage and mutagenicity were studied by testing colony forming efficiency, alkaline DNA unwinding and HPRT mutation assays, respectively. Additionally, co-exposure to a PARP-1 inhibitor was performed to test possible involvement of base excision repair (BER) in repair of Ni-induced DNA damage. The results showed that cell viability was reduced significantly (to 45% and 46%) after 48hours Ni-NP exposure at concentrations of 0.15 and 0.32g cm(-2). DNA damage was significantly increased after Ni-NP exposure in the presence of the BER inhibitor indicating that Ni-NP-induced DNA damages are subsequently repaired by BER. Furthermore, there was no increased HPRT mutation frequency following Ni-NP exposure. In conclusion, this study shows that Ni-NP treatment of lung fibroblasts in an air-liquid interface system that mimics real-life exposure, results in increased DNA strand breaks and reduced cellular viability. These DNA lesions were repaired with BER in an error-free manner without resulting in mutations. This study also underlines the importance of appropriate quantification of the actual exposure concentrations during air-liquid interface exposure studies. The aim of this study was to investigate the genotoxicity of airborne Ni nanoparticles using a recently developed air-liquid interface exposure system that mimics real-life exposure. Cytotoxicity, DNA damage and mutagenicity were in the V79 cell line. Ni nanoparticle exposure of the cells in the air-liquid interface resulted in increased DNA strand breaks and reduced cellular viability at concentrations of 0.15 and 0.32 g cm (-2). These DNA lesions were repaired with BER in an error-free manner without resulting in mutations
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| 22. |
- Latvala, Siiri, et al.
(författare)
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Nickel release, ROS generation and toxicity of Ni and NiO micro- and nanoparticles
- 2016
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:7
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Tidskriftsartikel (refereegranskat)abstract
- Occupational exposure to airborne nickel is associated with an elevated risk for respiratory tract diseases including lung cancer. Therefore, the increased production of Ni-containing nanoparticles necessitates a thorough assessment of their physical, chemical, as well as toxicological properties. The aim of this study was to investigate and compare the characteristics of nickel metal (Ni) and nickel oxide (NiO) particles with a focus on Ni release, reactive oxygen species (ROS) generation, cellular uptake, cytotoxicity and genotoxicity. Four Ni-containing particles of both nano-size (Ni-n and NiO-n) and micron-size (Ni-m1 and Ni-m2) were tested. The released amount of Ni in solution was notably higher in artificial lysosomal fluid (e.g. 80–100 wt% for metallic Ni) than in cell medium after 24h (ca. 1–3 wt% for all particles). Each of the particles was taken up by the cells within 4 h and they remained in the cells to a high extent after 24 h post-incubation. Thus, the high dissolution in ALF appeared not to reflect the particle dissolution in the cells. Ni-m1 showed the most pronounced effect on cell viability after 48 h (alamar blue assay) whereas all particles showed increased cytotoxicity in the highest doses (20–40 μg cm2) when assessed by colony forming efficiency (CFE). Interestingly an increased CFE, suggesting higher proliferation, was observed for all particles in low doses (0.1 or 1 μg cm-2). Ni-m1 and NiO-n were the most potent in causing acellular ROS and DNA damage. However, no intracellular ROS was detected for any of the particles. Taken together, micron-sized Ni (Ni-m1) was more reactive and toxic compared to the nano-sized Ni. Furthermore, this study underlines that the low dose effect in terms of increased proliferation observed for all particles should be further investigated in future studies.
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| 23. |
- Latvala, Siiri, et al.
(författare)
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Optimization of an air-liquid interface exposure system for assessing toxicity of airborne nanoparticles
- 2016
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Ingår i: Journal of Applied Toxicology. - : Wiley. - 0260-437X .- 1099-1263.
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Tidskriftsartikel (refereegranskat)abstract
- The use of refined toxicological methods is currently needed for characterizing the risks of airborne nanoparticles (NPs) to human health. To mimic pulmonary exposure, we have developed an air-liquid interface (ALI) exposure system for direct deposition of airborne NPs on to lung cell cultures. Compared to traditional submerged systems, this allows more realistic exposure conditions for characterizing toxicological effects induced by airborne NPs. The purpose of this study was to investigate how the deposition of silver NPs (AgNPs) is affected by different conditions of the ALI system. Additionally, the viability and metabolic activity of A549 cells was studied following AgNP exposure. Particle deposition increased markedly with increasing aerosol flow rate and electrostatic field strength. The highest amount of deposited particles (2.2 μg cm-2) at cell-free conditions following 2 h exposure was observed for the highest flow rate (390 ml min-1) and the strongest electrostatic field (±2 kV). This was estimated corresponding to deposition efficiency of 94%. Cell viability was not affected after 2 h exposure to clean air in the ALI system. Cells exposed to AgNPs (0.45 and 0.74 μg cm-2) showed significantly (P < 0.05) reduced metabolic activities (64 and 46%, respectively). Our study shows that the ALI exposure system can be used for generating conditions that were more realistic for in vitro exposures, which enables improved mechanistic and toxicological studies of NPs in contact with human lung cells.
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| 24. |
- Midander, Klara, et al.
(författare)
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Characterisation of nano- and micron-sized airborne and collected subway particles, a multi-analytical approach
- 2012
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 427, s. 390-400
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Tidskriftsartikel (refereegranskat)abstract
- Continuous daily measurements of airborne particles were conducted during specific periods at an underground platform within the subway system of the city center of Stockholm, Sweden. Main emphasis was placed on number concentration, particle size distribution, soot content (analyzed as elemental and black carbon) and surface area concentration. Conventional measurements of mass concentrations were conducted in parallel as well as analysis of particle morphology, bulk- and surface composition. In addition, the presence of volatile and semi volatile organic compounds within freshly collected particle fractions of PM 10 and PM 2.5 were investigated and grouped according to functional groups. Similar periodic measurements were conducted at street level for comparison.The investigation clearly demonstrates a large dominance in number concentration of airborne nano-sized particles compared to coarse particles in the subway. Out of a mean particle number concentration of 12000 particles/cm 3 (7500 to 20000 particles/cm 3), only 190 particles/cm 3 were larger than 250nm. Soot particles from diesel exhaust, and metal-containing particles, primarily iron, were observed in the subway aerosol. Unique measurements on freshly collected subway particle size fractions of PM 10 and PM 2.5 identified several volatile and semi-volatile organic compounds, the presence of carcinogenic aromatic compounds and traces of flame retardants.This interdisciplinary and multi-analytical investigation aims to provide an improved understanding of reported adverse health effects induced by subway aerosols.
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| 25. |
- Midander, Klara, et al.
(författare)
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Surface characteristics, copper release, and toxicity of nano- and micrometer-sized copper and copper(II) oxide particles : a cross-disciplinary study.
- 2009
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Ingår i: Small (Weinheim an der Bergstrasse, Germany). - : Wiley. - 1613-6829 .- 1613-6810. ; 5:3, s. 389-99
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Tidskriftsartikel (refereegranskat)abstract
- An interdisciplinary and multianalytical research effort is undertaken to assess the toxic aspects of thoroughly characterized nano- and micrometer-sized particles of oxidized metallic copper and copper(II) oxide in contact with cultivated lung cells, as well as copper release in relevant media. All particles, except micrometer-sized Cu, release more copper in serum-containing cell medium (supplemented Dulbecco's minimal essential medium) compared to identical exposures in phosphate-buffered saline. Sonication of particles for dispersion prior to exposure has a large effect on the initial copper release from Cu nanoparticles. A clear size-dependent effect is observed from both a copper release and a toxicity perspective. In agreement with greater released amounts of copper per quantity of particles from the nanometer-sized particles compared to the micrometer-sized particles, the nanometer particles cause a higher degree of DNA damage (single-strand breaks) and cause a significantly higher percentage of cell death compared to cytotoxicity induced by micrometer-sized particles. Cytotoxic effects related to the released copper fraction are found to be significantly lower than the effects related to particles. No DNA damage is induced by the released copper fraction.
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