| 1. |
- Lovén, Karin, et al.
(author)
-
Toxicological effects of zinc oxide nanoparticle exposure : an in vitro comparison between dry aerosol air-liquid interface and submerged exposure systems
- 2021
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In: Nanotoxicology. - : Taylor and Francis Ltd.. - 1743-5390 .- 1743-5404. ; 15:4, s. 494-510
-
Journal article (peer-reviewed)abstract
- Engineered nanomaterials (ENMs) are increasingly produced and used today, but health risks due to their occupational airborne exposure are incompletely understood. Traditionally, nanoparticle (NP) toxicity is tested by introducing NPs to cells through suspension in the growth media, but this does not mimic respiratory exposures. Different methods to introduce aerosolized NPs to cells cultured at the air-liquid-interface (ALI) have been developed, but require specialized equipment and are associated with higher cost and time. Therefore, it is important to determine whether aerosolized setups induce different cellular responses to NPs than traditional ones, which could provide new insights into toxicological responses of NP exposure. This study evaluates the response of human alveolar epithelial cells (A549) to zinc oxide (ZnO) NPs after dry aerosol exposure in the Nano Aerosol Chamber for In Vitro Toxicity (NACIVT) system as compared to conventional, suspension-based exposure: cells at ALI or submerged. Similar to other studies using nebulization of ZnO NPs, we found that dry aerosol exposure of ZnO NPs via the NACIVT system induced different cellular responses as compared to conventional methods. ZnO NPs delivered at 1.0 µg/cm2 in the NACIVT system, mimicking occupational exposure, induced significant increases in metabolic activity and release of the cytokines IL-8 and MCP-1, but no differences were observed using traditional exposures. While factors associated with the method of exposure, such as differing NP aggregation, may contribute toward the different cellular responses observed, our results further encourage the use of more physiologically realistic exposure systems for evaluating airborne ENM toxicity. © 2021 The Author(s).
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| 2. |
- Abrahamsson, Camilla, et al.
(author)
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Aerosolized particulate matter from fragmentation of carbon nanotube-enhanced concrete
- 2023
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In: Abstracts from the 2022 Airmon-10 conference and the 2023 Inhaled Particles and NanOEH conference. - 2398-7316 .- 2398-7308. ; 67:Supplement_1, s. i94-i95
-
Conference paper (peer-reviewed)abstract
- Construction and demolition workers are exposed to high levels of particulate matter (PM) from building materials throughout their working life. Although nano-enabled building materials (NEBMs) may improve the performance and functionality of buildings, concerns are being raised regarding health risks from occupational exposure to PM from NEBMs. In this work, an experimental set-up for integrated resuspension and characterization of PM from NEBMs was developed and tested using three types of concrete (low density, normal, high strength), each enhanced with Carbon Nanotubes (CNTs) at different concentrations (0, low, high). The performance of portable devices used in occupational exposure assessments (DustTrak and NanoTracer) was compared with stationary instruments and gravimetric filter techniques. 40-70% of the mass and 90-98% of the number of particles were within the respirable fraction, with primary modes at 150 nm and 2-3 µm. Addition of CNTs significantly decreased mean particle number concentrations (PNCs) across the entire characterized size range (7 nm - 20 µm) for low density concrete, whereas the opposite was the case for normal strength and high strength concrete. It was hypothesised that the concrete matrix primarily governs the PM formation, which is in turn modulated by CNT-matrix interactions either suppressing or supporting fragmentation during crushing. SEM imaging could display partially submerged CNTs protruding from concrete fragments. Fundamental interactions at the interface of the nanomaterial and the surrounding matrix needs to be investigated to determine how the PM generated from NEBMs differ from their non-nano counterparts and how to prevent future exposure during demolition.
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| 3. |
- Abrahamsson, Camilla, et al.
(author)
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Characterization of airborne dust emissions from three types of crushed multi-walled carbon nanotube-enhanced concretes
- 2024
-
In: NanoImpact. - : Elsevier B.V.. - 2452-0748. ; 34
-
Journal article (peer-reviewed)abstract
- Dispersing Multi-Walled Carbon Nanotubes (MWCNTs) into concrete at low (<1 wt% in cement) concentrations may improve concrete performance and properties and provide enhanced functionalities. When MWCNT-enhanced concrete is fragmented during remodelling or demolition, the stiff, fibrous and carcinogenic MWCNTs will, however, also be part of the respirable particulate matter released in the process. Consequently, systematic aerosolizing of crushed MWCNT-enhanced concretes in a controlled environment and measuring the properties of this aerosol can give valuable insights into the characteristics of the emissions such as concentrations, size range and morphology. These properties impact to which extent the emissions can be inhaled as well as where they are expected to deposit in the lung, which is critical to assess whether these materials might constitute a future health risk for construction and demolition workers. In this work, the impact from MWCNTs on aerosol characteristics was assessed for samples of three concrete types with various amounts of MWCNT, using a novel methodology based on the continuous drop method. MWCNT-enhanced concretes were crushed, aerosolized and the emitted particles were characterized with online and offline techniques. For light-weight porous concrete, the addition of MWCNT significantly reduced the respirable mass fraction (RESP) and particle number concentrations (PNC) across all size ranges (7 nm – 20 μm), indicating that MWCNTs dampened the fragmentation process by possibly reinforcing the microstructure of brittle concrete. For normal concrete, the opposite could be seen, where MWCNTs resulted in drastic increases in RESP and PNC, suggesting that the MWCNTs may be acting as defects in the concrete matrix, thus enhancing the fragmentation process. For the high strength concrete, the fragmentation decreased at the lowest MWCNT concentration, but increased again for the highest MWCNT concentration. All tested concrete types emitted <100 nm particles, regardless of CNT content. SEM imaging displayed CNTs protruding from concrete fragments, but no free fibres were detected.
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| 4. |
- Al-Rekabi, Zeinab, et al.
(author)
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Uncovering the cytotoxic effects of air pollution with multi-modal imaging of in vitro respiratory models
- 2023
-
In: Royal Society Open Science. - : Royal Society Publishing. - 2054-5703. ; 10:4
-
Journal article (peer-reviewed)abstract
- Annually, an estimated seven million deaths are linked to exposure to airborne pollutants. Despite extensive epidemiological evidence supporting clear associations between poor air quality and a range of short- and long-term health effects, there are considerable gaps in our understanding of the specific mechanisms by which pollutant exposure induces adverse biological responses at the cellular and tissue levels. The development of more complex, predictive, in vitro respiratory models, including two- and three-dimensional cell cultures, spheroids, organoids and tissue cultures, along with more realistic aerosol exposure systems, offers new opportunities to investigate the cytotoxic effects of airborne particulates under controlled laboratory conditions. Parallel advances in high-resolution microscopy have resulted in a range of in vitro imaging tools capable of visualizing and analysing biological systems across unprecedented scales of length, time and complexity. This article considers state-of-the-art in vitro respiratory models and aerosol exposure systems and how they can be interrogated using high-resolution microscopy techniques to investigate cell-pollutant interactions, from the uptake and trafficking of particles to structural and functional modification of subcellular organelles and cells. These data can provide a mechanistic basis from which to advance our understanding of the health effects of airborne particulate pollution and develop improved mitigation measures.
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| 5. |
- Bergman, Fanny, et al.
(author)
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Physicochemical metamorphosis of re-aerosolized urban PM2.5
- 2024
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In: Journal of Aerosol Science. - : Elsevier Ltd. - 0021-8502 .- 1879-1964. ; 181
-
Journal article (peer-reviewed)abstract
- The toxicity of particulate matter (PM) is dependent on particle physical and chemical properties and is commonly studied using in vivo and in vitro approaches. PM to be used for in vivo and in vitro studies is often collected on filters and then extracted from the filter surface using a solvent. During extraction and further PM sample handling, particle properties change, but this is often neglected in toxicology studies, with possible implications for health effect assessment. To address the current lack of knowledge and investigate changes in particle properties further, ambient PM with diameter less than 2.5 μm (PM2.5) was collected on filters at an urban site and extracted using a standard methanol protocol. After extraction, the PM was dried, dispersed in water and subsequently nebulized. The resulting aerosol properties were then compared to those of the ambient PM2.5. The number size distribution for the nebulized aerosol resembled the ambient in terms of the main mode diameter, and >90 % of particle mass in the nebulized size distribution was still in the PM2.5 range. Black carbon made up a similar fraction of PM mass in nebulized as in ambient aerosol. The sulfate content in the nebulized aerosol seemed depleted and the chemical composition of the organic fraction was altered, but it remains unclear to what extent other non-refractory components were affected by the extraction process. Trace elements were not distributed equally across size fractions, neither in ambient nor nebulized PM. Change in chemical form was studied for zinc, copper and iron. The form did not appear to be different between the ambient and nebulized PM for iron and copper, but seemed altered for zinc. Although many of the studied properties were reasonably well preserved, it is clear that the PM2.5 collection and re-aerosolization process affects particles, and thus potentially also their health effects. Because of this, the effect of the particle collection and extraction process must be considered when evaluating cellular and physiological outcomes upon PM2.5 exposure.
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| 6. |
- Dahl, Jonas, et al.
(author)
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Avancerad spektroskopisk speciering av metaller i askan från avfallsförbränning
- 2020
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Reports (other academic/artistic)abstract
- Användning av sekundära råvaror har på senare tid fått ett ökat fokus med den drivkraft som finns kring cirkulär omställning. Möjligheten att nyttja askor ifrån avfallsförbränning är starkt beroende av deras innehåll av toxiska men också värdefulla komponenter, bland annat metaller.Föreliggande projekt har undersökt möjligheterna med att använda röntgenabsorptionsspektroskopi (XAS) för att påvisa de dominerande förekomstformerna av metallerna zink, bly, koppar och antimon i askor från förbränning av avfall. En ökad kunskap om dessa förekomstformer kan ge nya möjligheter till klassificering av bottenaskor (slaggrus) samt ge viktig information för optimering av behandlingsmetoder för att endera stabilisera flygaskor för säker deponi eller för utvinning av värdefulla metaller. I projektet ingick därför analyser av ett mindre antal askor representerande både färska och lagrade bottenaskor samt behandlade och icke behandlade flygaskor. Dessutom representerades olika förbränningsteknologier, såsom rosterpanna, roterugn och cirkulerande fluidiserad bädd (CFB).I projektet har röntgen-absorptionsspektroskopimätningar (XAS) genomförts vid BALDER som är ett av strålrören på MAX IV laboratoriet, Lund. XAS kan delas in i två delar, EXAFS och XANES, där XANES utnyttjar den första delen av spektrumet (energier närmast absorptionskanten) och kräver betydligt kortare analystid än en full EXAFS analys (högre energier). Fokus har därför legat på XANES i detta projekt då det är den teknik som har störst potential att fungera som en tidseffektiv standardanalys på MAX IV, speciellt för heterogena prov som genererar hög brusnivå vilket är typiskt för askor.Metoden är väldigt beroende av relevanta referensspektrum för att kunna identifiera de olika förekomstformerna. En stor del av arbetet har därför varit att identifiera, framskaffa, kontrollera renhetsgrad för och slutligen mäta på de totalt 43 referensmaterial som använts i analyserna (14 zinkföreningar, 14 kopparföreningar, 10 blyföreningar och 3 antimonföreningar). Dessa spektrum ligger kvar i en databas på MAX IV och kan därför utökas och kompletteras med nya relevanta referensmaterial för att ytterligare förbättra metoden framöver. Dessa är också tillgängliga för andra användare av MAX IV.Resultaten visade inte oväntat på att bottenaskor är mer heterogena än flygaskor vilket gav mer brus i analyserna av dessa askor, men med god reproducerbarhet. Övriga trender är beroende på vilket grundämne som undersöks.Den klart vanligaste förekomstformer av zink är silikatet hemimorfit (Zn4Si2O7(OH)2·H2O) både i flyg- och bottenaskor. Analyserna föreslår att ca. 20-40 % av zink återfinns i denna form i de flesta askorna. Övriga dominerande förekomstformer sett till andelen zink är Zn5(CO3)2(OH)6 (Hydrozinkit) och ett annat silkat som heter Willemite och har formeln Zn2SiO3 men med en större skillnad mellan de olika analyserade askorna. En viss andel zinkklorid, ZnCl2, återfinns också i de flesta askorna.Den vanligaste förekomstformen av koppar i flygaskor är Cu(OH)2 (30–55%) men resultaten för bottenaskorna visar på en mer komplex sammansättning med olika oxidformer (CuO, Cu2O, CuFe2O4, Cu2SiO3) men också på förekomst av karbonat (CuCO3*Cu(OH)2) i ett av de lagrade proven.Den vanligaste förekomstformen av bly är associerad med någon form av silikat (PbSiO3 eller bundet till amorft SiO2 – liknande strukturen i Pb-glas), men även PbCl2 är vanligt förekommande, speciellt i flygaskor.Antimon var bara delvis inkluderad i studien och begränsat till tre referenser. Analysen fokuserade därför på att detektera skillnader före och efter behandling av flygaska. Ingen sådan skillnad kunde detekteras. Värt att notera är att Sb-spektrumet för den bottenaska som analyserades är identisk med det för referensen Sb2O5 och att oxidationstalet för Sb i alla askor ligger nära den för samma referens.En slutsats av analyserna var att vissa av referensmaterialens spektrum är mycket lika vilket resulterar i att några referenser som t.ex. ZnS aktivt behövdes selekteras bort vid analyserna baserat på kunskap om hur trolig deras förekomst i askorna är. Det finns också starka indikationer på att fler referensmaterial behövs för att beskriva några av askorna. En kombination av andra mätmetoder som t.ex. μ-XRF föreslås därför som en möjlighet i framtida arbete för att identifiera viktiga saknade referensmaterial. Dessutom skulle en jämförelse med lakanalyser vara kunskapsbyggande.Sammanfattningsvis har det i projektet utvecklats en fungerande analysmetod som har potential att kunna bli industriellt gångbar. De resultat som tagits fram kring möjliga förekomstformer är, sett till vad som finns publicerat i litteraturen, betydande. Men för att dra riktiga slutsatser kring olika påverkansfaktorer krävs betydligt fler riktade analyser.
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| 7. |
- Dobric, Julia, et al.
(author)
-
Physical activity changes the deposited fractions of particles in the respiratory tract of adults and children
- 2022
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In: ; , s. 45-45
-
Conference paper (peer-reviewed)abstract
- Exposure to ambient air pollution can cause a numberof health problems and may be particularly dangerous to susceptible population groups such as children. Health effects caused by air pollution are criticallydependent on both the deposited fraction (DF) of the inhaled particles and in what region of the respiratory tract the deposition takes place. With increasing physical activity, the breathing pattern is altered and the airflow in the respiratory tract increase, this affects the DF and deposition site. In this study we investigated changes in DF at increasing physical activity for three population groups: ~5 and 10 year-old children, and adults.Our results indicate that the variation in total DF with physical activity is minor, but that the DF for the UFPs increase in the AI region at higher activity levels. This is important since the removal of particles in the AI region is not effective and UFPs are believed to pose a specific health risk. Therefore, activity patterns and DF of different population groups need to be considered when estimating particle dose and evaluating health risks.
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| 8. |
- Dobric, Julia, et al.
(author)
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Preschool Children’s Inhalation Rates Estimated from Accelerometers—A Tool to Estimate Children’s Exposure to Air Pollution
- 2022
-
In: Aerosol and Air Quality Research. - : AAGR Aerosol and Air Quality Research. - 1680-8584 .- 2071-1409. ; 22:8
-
Journal article (peer-reviewed)abstract
- Children are particularly sensitive to air pollution exposure, and their personal exposures may differ significantly from those of adults. One key factor for understanding the personal inhaled dose of air pollutants is the respiratory minute ventilation (Ve). To estimate the amount of particles circulated through the lungs, 24 h averages of Ve are often used. These averages poorly capture variations in Ve during the day, and between individuals. We here develop and implement a concept to assess individual Ve of children, with minimal impact on their natural activity and movement pattern by using ActiGraph GT3X+ accelerometers. Activity of 136 preschool children in the ages 3 to 5 years was logged using accelerometers while the children attended their preschools during a week. A linear regression equation is developed and used for estimating Ve from the accelerometer data retrieved for each individual child. The results show large variations in weekly average Ve between individuals, ranging from 0.33 to 0.48 L min–1 kg–1. Over the days the averages of the individuals’ 1st and 3rd quartiles were 0.28 and 0.48 L min–1 kg–1, respectively. Outdoor activities resulted in a 17% higher Ve than indoor activities, which may be important to consider when estimating the inhaled dose of air pollutants since pollution levels and particle toxicities can be different indoors and outdoors. The observations motivate the use of individual values of Ve in exposure assessments and suggest that accelerometers are a suitable tool for estimating children’s individual Ve in their natural environment. Combined with time resolved local air pollution monitoring, these measurements can provide the basis of a more precise estimate of children’s inhaled dose of air pollutants. © The Author(s).
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| 9. |
- Gericke, Sabrina Maria, et al.
(author)
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In Situ H2 Reduction of Al2O3-Supported Ni- and Mo-Based Catalysts
- 2022
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In: Catalysts. - : MDPI. - 2073-4344. ; 12:7
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Journal article (peer-reviewed)abstract
- Nickel (Ni)-promoted Molybdenum (Mo)-based catalysts are used for hydrotreatment processes in the chemical industry where the catalysts are exposed to high-pressure H2 at elevated temperature. In this environment, the catalyst transforms into the active phase, which involves the reduction of the oxide. Here, we report on the first in situ study on the reduction of alumina supported Ni- and Mo-based catalysts in 1 mbar H2 using ambient-pressure X-ray photoelectron spectroscopy (APXPS). The study confirms that mixing Ni and Mo lowers the reduction temperature of both Ni- and Mo-oxide as compared to the monometallic catalysts and shows that the MoO3 reduction starts at a lower temperature than the reduction of NiO in NiMo/Al2O3 catalysts. Additionally, the reduction of Ni and Mo foil was directly compared to the reduction of the Al2O3-supported catalysts and it was observed that the reduction of the supported catalysts is more gradual than the reduction of the foils, indicating a strong interaction between the Ni/Mo and the alumina support. © 2022 by the authors.
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| 10. |
- Janhäll, Sara, et al.
(author)
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A new method and first results for comparing emissions of fumes during construction of asphalt surfaces
- 2024
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In: Construction and Building Materials. - : Elsevier Ltd. - 0950-0618 .- 1879-0526. ; 422
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Journal article (peer-reviewed)abstract
- A novel laboratory methodology for analysing hot asphalt fumes from various paving materials is presented and evaluated. This method facilitates comparative assessments, aiming to enhance occupational safety for asphalt workers and ensure safe implementation of new paving materials. Comparative analyses of emissions to air were conducted on standard asphalt and rubber-modified asphalt at different temperatures. The temperature significantly influences PAH emissions. Rubber-modified asphalt demonstrated higher PAH emissions at equivalent temperatures compared to standard asphalt, predominantly naphthalene. Even heavier PAHs as benzo(a)pyrene were occasionally high. Notably, at recommended working temperatures the standard asphalt resulted in higher emissions, comprising heavier PAHs compared to rubber asphalt.
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| 11. |
- Janhäll, Sara, 1965-, et al.
(author)
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Release of carbon nanotubes during combustion of polymer nanocomposites in a pilot-scale facility for waste incineration
- 2021
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In: NanoImpact. - : Elsevier BV. - 2452-0748. ; 24
-
Journal article (peer-reviewed)abstract
- Nanocomposites, formed by incorporating nanoparticles into a matrix of standard materials, are increasing on the market. Little focus has been directed towards safe disposal and recycling of these new materials even though the disposal has been identified as a phase of the products' life cycle with a high risk of uncontrolled emissions of nanomaterials. In this study, we investigate if the carbon nanotubes (CNTs), when used as a filler in two types of polymers, are fully destructed in a pilot-scale combustion unit designed to mimic the combustion under waste incineration. The two polymer nanocomposites studied, polycarbonate (PC) with CNT and high-density polyethylene (HDPE) with CNT, were incinerated at two temperatures where the lower temperature just about fulfilled the European waste incineration directive while the upper was chosen to be on the safe side of fulfilling the directive. Particles in the flue gas were sampled and analysed with online and offline instrumentation along with samples of the bottom ash. CNTs could be identified in the flue gas in all experiments, although present to a greater extent when the CNTs were introduced in PC as compared to in HDPE. In the case of using PC as polymer matrix, CNTs were identified in 3–10% of the analysed SEM images while for HDPE in only ~0.5% of the images. In the case of PC, the presence of CNTs decreased with increasing bed temperature (from 10% to 3% of the images). The CNTs identified were always in bundles, often coated with remnants of the polymer, forming particles of ~1–4 μm in diameter. No CNTs were identified in the bottom ash, likely explained by the difference in time when the bottom ash and fly ash are exposed to high temperatures (~hours compared to seconds) in the pilot facility. The results suggest that the residence time of the fly ash in the combustion zone is not long enough to allow full oxidation of the CNTs. Thus, the current regulation on waste incineration (requiring a residence time of the flue gas >850 °C during at least 2 s) may not be enough to obtain complete destruction of CNTs in polymer composites. Since several types of CNTs are known to be toxic, we stress the need for further investigation of the fate and toxicity of CNTs in waste treatment processes.
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| 12. |
- Kjellberg Jensen, Johan, et al.
(author)
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Quantifying the influence of urban biotic and abiotic environmental factors on great tit nestling physiology
- 2023
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In: Science of the Total Environment. - : Elsevier B.V.. - 0048-9697 .- 1879-1026. ; 859
-
Journal article (peer-reviewed)abstract
- There is a long history of avian studies investigating the impacts of urbanization. While differences in several life-history traits have been documented, either between urban and rural populations or across generalized urbanization gradients, a detailed understanding of which specific environmental variables cause these phenotypic differences is still lacking. Here, we quantified several local environmental variables coupled to urbanization (air pollution, tree composition, ambient temperature, and artificial light at night [ALAN]) within territories of breeding great tits (Parus major). We linked the environmental variables to physiological measures of the nestlings (circulating fatty acid composition [FA], antioxidant capacity and an oxidative damage marker [malondialdehyde; MDA]), to garner a mechanistic understanding of the impact of urbanization. We found that the antioxidant capacity of nestlings decreased with higher numbers of oak trees and levels of PM2.5 (airborne particulate matter with a diameter < 2.5 μm). Furthermore, the ratio of ω6:ω3 polyunsaturated FAs, important for immune function, was positively correlated with PM2.5 concentration, while being negatively associated with ambient temperature and number of non-native trees in the territory. Body mass and wing length both increased with the number of local oak trees. We also show, through a principal component analysis, that while the environmental variables fall into an urbanization gradient, this gradient is insufficient to explain the observed physiological responses. Therefore, accounting for individual environmental variables in parallel, and thus allowing for interactions between these, is crucial to fully understand of the urban ecosystem. © 2022 The Authors
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| 13. |
- Linell, Julia, et al.
(author)
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Alterations of particle deposition in the respiratory tract at increasing activity
- 2023
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Conference paper (other academic/artistic)abstract
- The deposited dose of particles in the respiratory tract is an important factor for understanding health effects of aerosol particles. It is a combination of the exposure, volume of inhaled air and particle deposition. At increasing activity the minute ventilation ( volume of breath x number of breaths ) increase . Little is known about if and how this affects the regional particle deposition.
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| 14. |
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| 15. |
- Linell, Julia, et al.
(author)
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Effects of breathing variables on modelled particle lung deposition at physical activity for children and adults
- 2024
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In: Air Quality, Atmosphere and Health. - : Springer Science and Business Media B.V.. - 1873-9318 .- 1873-9326. ; 17:4, s. 843-856
-
Journal article (peer-reviewed)abstract
- The respiratory tract deposited fraction (DF) is the link between exposure and health effects of airborne particles. Here, we investigate how breathing pattern alterations at increasing physical activity affect DF in different regions of the respiratory tract and compare DF between adults and children (5 and 10 years old). We performed a literature review on the alteration of tidal volume with minute ventilation at increasing physical activity and used the results to model the size resolved (0.001–10 µm) DF, primarily using the deposition models from NCRP and Yeh and Schum (1980), but also MPPD. We found a shift in the deposited size distribution with increasing physical activity—DF of ultrafine particles increased in the alveolar region and decreased in the other regions, while DF of coarser particles decreased in the alveolar region and increased in the extra-thoracic region. Children had a 10–20% higher DF of ultrafine particles in the alveolar region compared to adults. We also present parametrizations of the daily average size resolved (0.005–5 µm) DF, accounting for varying physical activity throughout the day and oral/nasal breathing. These can be applied to any size distribution to estimate deposited doses. We found that deposited mass and number doses were more than twice as high for 5-year-olds compared to adults when normalized for body weight, primarily caused by their higher weight normalized minute ventilation. This demonstrates the importance of studying children’s exposure to air pollution and not only rely on data from adults.
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| 16. |
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| 17. |
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| 18. |
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| 19. |
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| 20. |
- Lovén, Karin, et al.
(author)
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Size-resolved characterization of particles >10 nm emitted to air during metal recycling
- 2023
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In: Environment International. - : Elsevier Ltd. - 0160-4120 .- 1873-6750. ; 174
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Journal article (peer-reviewed)abstract
- Background: In the strive towards a circular economy, metal waste recycling is a growing industry. During the recycling process, particulate matter containing toxic and allergenic metals will be emitted to the air causing unintentional exposure to humans and environment. Objective: In this study detailed characterization of particle emissions and workplace exposures were performed, covering the full size range from 10 nm to 10 µm, during recycling of three different material flows: Waste of electrical and electronic equipment (WEEE), metal scrap, and cables. Methods: Both direct-reading instruments (minute resolution), and time-integrated filter measurements for gravimetric and chemical analysis were used. Additionally, optical sensors were applied and evaluated for long-term online monitoring of air quality in industrial settings. Results: The highest concentrations, in all particle sizes, and with respect both to particle mass and number, were measured in the WEEE flow, followed by the metal scrap flow. The number fraction of nanoparticles was high for all material flows (0.66–0.86). The most abundant metals were Fe, Al, Zn, Pb and Cu. Other elements of toxicological interest were Mn, Ba and Co. Significance: The large fraction of nanoparticles, and the fact that their chemical composition deviate from that of the coarse particles, raises questions that needs to be further addressed including toxicological implications, both for humans and for the environment. © 2023 The Authors
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| 21. |
- Nielsen, Maria, et al.
(author)
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Nanomaterials in the European chemicals legislation-methodological challenges for registration and environmental safety assessment
- 2021
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In: Environmental Science: Nano. - : Royal Society of Chemistry. - 2051-8153 .- 2051-8161. ; 8:3, s. 731-747
-
Journal article (peer-reviewed)abstract
- In the European Union the Annexes of its chemical legislation (REACH) were revised and now clarify the technical data requirements for nanomaterials (NMs). These new provisions, effective from January 1, 2020, introduce requirements for manufacturers, importers and downstream users regarding registration and safety assessment of NMs. This study aims to assess the availability and suitability of methods needed to comply with the new regulatory provisions on NMs for physico-chemical characterisation and environmental fate and effects. The scientific literature and relevant test guideline frameworks were reviewed to identify applicable methods. These were subsequently evaluated and categorised as either: 'internationally accepted test guideline or standard (TGS)', 'internationally accepted test guideline or standard under development (TGSUD)', 'established as standard methods in scientific literature (SCI)', 'other methods and/or more research needed (O)' or 'no method (N)'. We find that 80% of the information requirements and a bit more than 40% of the waiving criteria in the new REACH Annexes are supported by methods that are available as TGS, TGSUD or SCI. Most of the relevant methods in the scientific literature are included in recent OECD guidance documents or ECHA guidance. We recommend that a targeted effort is made to develop protocols and guidelines for methods to determine NM adsorption/desorption, degradation, exposure scenarios and ability to cross biological membranes. Here methods to fulfil the information requirements and waiving criteria are currently lacking. Furthermore, we recommend that increasing attention is directed towards regulatory reliability and relevance of the information that is submitted by the registrants.
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| 22. |
- Odnevall, Inger, 1965-, et al.
(author)
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Characterization and Toxic Potency of Airborne Particles Formed upon Waste from Electrical and Electronic Equipment Waste Recycling : A Case Study
- 2023
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In: ACS ENVIRONMENTAL AU. - : American Chemical Society (ACS). - 2694-2518. ; 3:6, s. 370-382
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Journal article (peer-reviewed)abstract
- Manual dismantling, shredding, and mechanical grinding of waste from electrical and electronic equipment (WEEE) at recycling facilities inevitably lead to the accidental formation and release of both coarse and fine particle aerosols, primarily into the ambient air. Since diffuse emissions to air of such WEEE particles are not regulated, their dispersion from the recycling plants into the adjacent environment is possible. The aim of this interdisciplinary project was to collect and characterize airborne WEEE particles smaller than 1 mu m generated at a Nordic open waste recycling facility from a particle concentration, shape, and bulk and surface composition perspective. Since dispersed airborne particles eventually may reach rivers, lakes, and possibly oceans, the aim was also to assess whether such particles may pose any adverse effects on aquatic organisms. The results show that WEEE particles only exerted a weak tendency toward cytotoxic effects on fish gill cell lines, although the exposure resulted in ROS formation that may induce adverse effects. On the contrary, the WEEE particles were toxic toward the crustacean zooplankter Daphnia magna, showing strong effects on survival of the animals in a concentration-dependent way.
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| 23. |
- Oggiano, Florian, et al.
(author)
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Overlapping morphological, immunohistochemical and genetic features of superficial CD34-positive fibroblastic tumor and PRDM10-rearranged soft tissue tumor.
- 2022
-
In: Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc. - : Elsevier BV. - 1530-0285. ; 35:6, s. 767-776
-
Journal article (peer-reviewed)abstract
- Superficial CD34-positive fibroblastic tumor (SCD34FT) is a recently recognized soft tissue tumor that is considered to be of borderline malignancy. The pathogenesis of this tumor remains incompletely understood, but it has been suggested that SCD34FT overlaps with tumors showing fusions involving the PRDM10 gene. Previous analyses of PRDM10-rearranged tumors have demonstrated that they have a distinct gene expression profile, resulting in high expression of CADM3 (also known as SynCam3), which can be detected immunohistochemically. Here, we investigated a series (n=43) of SCD34FT or PRDM10-rearranged tumors and potential mimics (n=226) with regard to morphological, genetic, and immunohistochemical features. The results show that SCD34FT and PRDM10-rearranged tumor are morphologically indistinguishable; 41 of 43 tumors of both entities are CADM3-positive. Hence, we suggest that they constitute a single entity, preferably referred to as SCD34FT. Expression of CADM3 was only rarely seen in other soft tissue tumors, except in tumors with Schwann cell differentiation. Thus, IHC for CADM3, in combination with the characteristic morphological features, is a valuable adjunct in the diagnosis of SCD34FT.
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| 24. |
- Petersson-Sjögren, Madeleine, et al.
(author)
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Airspace Dimension Assessment with Nanoparticles (AiDA) in Comparison to Established Pulmonary Function Tests
- 2022
-
In: International Journal of Nanomedicine. - : Dove Medical Press Ltd. - 1176-9114 .- 1178-2013. ; 17, s. 2777-2790
-
Journal article (peer-reviewed)abstract
- Background: Airspace Dimensions Assessment with nanoparticles (AiDA) is a new method for non-invasive measurement of pulmonary distal airspaces. The aim of this study was to compare AiDA measurements with other pulmonary function variables to better understand the potential of AiDA in a clinical context. Methods: AiDA measurements and pulmonary function tests were performed in 695 subjects as part of the Swedish CArdioPulmonary bioImage Study. The measurement protocol included spirometry, measurement of diffusing capacity of carbon monoxide, oscillometry and pulmonary computed tomography. AiDA indices were compared to all other pulmonary examination measurements using multivariate statistical analysis. Results: Our results show that AiDA measurements were significantly correlated with other pulmonary function examination indices, although covariance was low. We found that AiDA variables explained variance in the data that other lung function variables only influenced to a minor extent. Conclusion: We conclude that the AiDA method provides information about the lung that is inaccessible with more conventional lung function techniques. © 2022 Petersson-Sjögren et al.
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| 25. |
- Petersson Sjögren, Madeleine, et al.
(author)
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Sensitive methods for assessment of lung health in welders and controls
- 2023
-
In: Respiratory Medicine. - : W.B. Saunders Ltd. - 0954-6111 .- 1532-3064. ; 212
-
Journal article (peer-reviewed)abstract
- Background: Welders are exposed to gas and particle emissions that can cause severe lung disease, such as chronic obstructive pulmonary disease (COPD), a leading cause of mortality and morbidity worldwide. It is difficult to detect COPD early and therefore mitigating measures may be delayed. The aim of this study was to investigate lung health in welders and evaluate new sensitive methods with potential to assess early onset pulmonary changes in occupational settings. Methods: This study assessed the lung health and symptoms in active welders (n = 28) and controls (n = 17). Lung measurements were performed with standard spirometry and new methods: airspace dimension assessment (AiDA), oscillometry, blood serum biomarkers (club cell secretory protein 16, surfactant protein D, matrix metalloproteinases, fibroblast, hepatocyte growth factor, interleukins), and one urine biomarker (desmosine). Results: According to spirometry measurements, all participants had normal lung function. However, prevalence of cough was significantly higher among welders compared with controls and lung changes were found in welders with the novel methods. Welders had significantly higher respiratory system resistance assessed with oscillometry, serum levels of metalloproteinases 9 and hepatocyte growth factor, compared with controls. Airspace dimensions were on average higher among welders compared with controls, but the difference was not significant. The number of welding years correlated with decreased respiratory system reactance and increased serum levels of matrix metalloproteinases 9, interleukin 6, and hepatocyte growth factor. Airspace dimension assessment indices were correlated with increasing levels of inflammatory markers and matrix metalloproteinases. Conclusions: This study indicated the potential to use new and more sensitive methods for identification of changes in lungs when standard spirometry failed to do so. © 2023 The Authors
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| 26. |
- Rissler, Jenny, et al.
(author)
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An experimental study on lung deposition of inhaled 2 μm particles in relation to lung characteristics and deposition models
- 2023
-
In: Particle and Fibre Toxicology. - : BioMed Central Ltd. - 1743-8977. ; 20
-
Journal article (peer-reviewed)abstract
- Background: The understanding of inhaled particle respiratory tract deposition is a key link to understand the health effects of particles or the efficiency for medical drug delivery via the lung. However, there are few experimental data on particle respiratory tract deposition, and the existing data deviates considerably when comparing results for particles > 1 μm. Methods: We designed an experimental set-up to measure deposition in the respiratory tract for particles > 1 μm, more specifically 2.3 μm, with careful consideration to minimise foreseen errors. We measured the deposition in seventeen healthy adults (21–68 years). The measurements were performed at tidal breathing, during three consecutive 5-minute periods while logging breathing patterns. Pulmonary function tests were performed, including the new airspace dimension assessment (AiDA) method measuring distal lung airspace radius (r AiDA). The lung characteristics and breathing variables were used in statistical models to investigate to what extent they can explain individual variations in measured deposited particle fraction. The measured particle deposition was compared to values predicted with whole lung models. Model calculations were made for each subject using measured variables as input (e.g., breathing pattern and functional residual capacity). Results: The measured fractional deposition for 2.3 μm particles was 0.60 ± 0.14, which is significantly higher than predicted by any of the models tested, ranging from 0.37 ± 0.08 to 0.53 ± 0.09. The multiple-path particle dosimetry (MPPD) model most closely predicted the measured deposition when using the new PNNL lung model. The individual variability in measured particle deposition was best explained by breathing pattern and distal airspace radius (r AiDA) at half inflation from AiDA. All models underestimated inter-subject variability even though the individual breathing pattern and functional residual capacity for each participant was used in the model. Conclusions: Whole lung models need to be tuned and improved to predict the respiratory tract particle deposition of micron-sized particles, and to capture individual variations – a variation that is known to be higher for aged and diseased lungs. Further, the results support the hypothesis that the AiDA method measures dimensions in the peripheral lung and that r AiDA, as measured by the AiDA, can be used to better understand the individual variation in the dose to healthy and diseased lungs.
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| 27. |
- Rissler, Jenny, et al.
(author)
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Identification and Quantification of Chemical Forms of Cu and Zn in MSWI Ashes Using XANES
- 2020
-
In: Energy & Fuels. - : American Chemical Society. - 0887-0624 .- 1520-5029. ; 34:11, s. 14505-14514
-
Journal article (peer-reviewed)abstract
- Incineration is in many countries a common treatment method for municipal solid waste, and utilization of the ash residues has attracted significant interest. The bottom ash is best suited as a secondary construction material, whereas the fly ash is being investigated as a secondary raw material for recovery of, for example, Zn, Cu, and salts. For both types of application, knowledge about the chemical speciation of Zn and Cu in the ashes is valuable. The present work focuses on identifying and quantifying the chemical species of Zn and Cu in 12 samples of fly ash and bottom ash from three waste-to-energy plants using X-ray absorption near edge structure (XANES). The XANES spectra of the ash samples showed similar distinctive features, and both in the bottom and fly ash samples, the same chemical forms were identified but in various ratios. Cu and Zn occurred in several chemical forms, with typically 5-7 forms present in the same sample. For Cu, the XANES spectra of the fly ash samples were nearly identical, indicating very similar chemical speciation (same chemical forms and similar ratios). Cu was found to exist in various oxide, hydroxide, chloride, silicate, and metallic forms. The most commonly occurring Zn compounds were the aluminate, ferrite, silicate, and oxide along with chloride, basic carbonate (hydrozincite), and occasionally metallic forms, probably alloyed with Cu in brass. Cu occurred in different oxidation states from zero to +II, with a higher prevalence of the lower oxidation states in bottom ash than in fly ash. Zn occurred mainly in oxidation state +II in all ashes analyzed. Finally, we showed that during outdoor storage of bottom ash, levels of Cu and Zn hydroxycarbonates were increased compared to fresh bottom ash. This carbonate formation aims to make Cu and Zn less leachable.
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| 28. |
- Rissler, Jenny, et al.
(author)
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Missed Evaporation from Atmospherically Relevant Inorganic Mixtures Confounds Experimental Aerosol Studies
- 2023
-
In: Environmental Science and Technology. - : American Chemical Society. - 0013-936X .- 1520-5851. ; 57:7, s. 2706-2714
-
Journal article (peer-reviewed)abstract
- Sea salt aerosol particles are highly abundant in the atmosphere and play important roles in the global radiative balance. After influence from continental air, they are typically composed of Na+, Cl-, NH4+, and SO42- and organics. Analogous particle systems are often studied in laboratory settings by atomizing and drying particles from a solution. Here, we present evidence that such laboratory studies may be consistently biased in that they neglect losses of solutes to the gas phase. We present experimental evidence from a hygroscopic tandem differential mobility analyzer and an aerosol mass spectrometer, further supported by thermodynamic modeling. We show that, at normally prevailing laboratory aerosol mass concentrations, for mixtures of NaCl and (NH4)2SO4, a significant portion of the Cl- and NH4+ ions are lost to the gas phase, in some cases, leaving mainly Na2SO4 in the dry particles. Not considering losses of solutes to the gas phase during experimental studies will likely result in misinterpretation of the data. One example of such data is that from particle water uptake experiments. This may bias the explanatory models constructed from the data and introduce errors inte predictions made by air quality or climate models. © 2023 The Authors.
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| 29. |
- Rissler, Jenny, et al.
(author)
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Zinc speciation in fly ash from MSWI using XAS - novel insights and implications
- 2024
-
In: Journal of Hazardous Materials. - : Elsevier B.V.. - 1873-3336 .- 0304-3894. ; 477
-
Journal article (peer-reviewed)abstract
- The chemical forms of zinc in fly ash from municipal solid waste incineration (MSWI) crucially affect ash management, influencing both material recovery options and the risk of unwanted leaching into ecosystems. The zinc speciation was investigated in fly ash samples sourced from full-scale MSWI plants, including four grate fired boilers (GB) and one fluidized bed boiler (FB). We applied X-ray Absorption Spectroscopy (XAS), and the spectra were analyzed against a unique library of over 30 relevant compounds, tailored to the nuances of zinc chemistry of fly ash. Nano-XANES and sequential leaching were employed as complementary analytical methods. Multiple chemical forms of zinc were found in the ash, whereof potassium zinc chloride salts (K2ZnCl4) emerged as the predominant form in GB fly ash representing 41–64 % of the zinc content, while less for FB fly ash (19 %). The mere exposure to humidity in the air during storage resulted in hydroxylation of the alkali zinc chlorides into Zn5(OH)8Cl2·H2O. Other forms of zinc in the ash were Zn4Si2O7(OH)2·H2O, ZnFe2O4, ZnAl2O4, surface adsorbed zinc, and Zn5(CO3)2(OH)6. Notably, the proportion of zinc in spinel forms (ZnFe2O4 and ZnAl2O4) increased threefold in FB ash compared to GB ash, representing ∼60 % and ∼10–20 % of the zinc, respectively.
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| 30. |
- Sjödin, Veronica, et al.
(author)
-
Transition metal valence in commercial glasses analysed using X-ray Absorption Spectroscopy at Balder beamline, MAX IV
- 2022
-
Reports (other academic/artistic)abstract
- The stone wool manufacturer Paroc (a part of Owens Corning) considers blending in additional waste materials into the production to obtain a more sustainable product. By using waste material that otherwise would go to the landfill also less virgin raw material (volcanic rock) would be used. The waste material contains manganese (Mn) which may potentially affect the iron (Fe) redox equilibria that greatly affects the melt and product properties. Paroc therefor wish to understand and simulate the effect of blending in additional waste material in their product.
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| 31. |
- Stockfelt, Leo, 1981, et al.
(author)
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A controlled chamber study of effects of exposure to diesel exhaust particles and noise on heart rate variability and endothelial function
- 2022
-
In: Inhalation Toxicology. - : Taylor and Francis Ltd.. - 0895-8378 .- 1091-7691. ; 34:5-6, s. 159-170
-
Journal article (peer-reviewed)abstract
- Background: Adverse cardiovascular effects are associated with both diesel exhaust and road traffic noise, but these exposures are hard to disentangle epidemiologically. We used an experimental setup to evaluate the impact of diesel exhaust particles and traffic noise, alone and combined, on intermediary outcomes related to the autonomic nervous system and increased cardiovascular risk. Methods: In a controlled chamber 18 healthy adults were exposed to four scenarios in a randomized cross-over fashion. Each exposure scenario consisted of either filtered (clean) air or diesel engine exhaust (particle mass concentrations around 300 µg/m3), and either low (46 dB(A)) or high (75 dB(A)) levels of traffic noise for 3 h at rest. ECG was recorded for 10-min periods before and during each exposure type, and frequency-domain heart rate variability (HRV) computed. Endothelial dysfunction and arterial stiffness were assessed after each exposure using EndoPAT 2000. Results: Compared to control exposure, HRV in the high frequency band decreased during exposure to diesel exhaust, both alone and combined with noise, but not during noise exposure only. These differences were more pronounced in women. We observed no synergistic effects of combined exposure, and no significant differences between exposure scenarios for other HRV indices, endothelial function or arterial stiffness. Conclusion: Three-hour exposure to diesel exhaust, but not noise, was associated with decreased HRV in the high frequency band. This indicates activation of irritant receptor-mediated autonomic reflexes, a possible mechanism for the cardiovascular risks of diesel exposure. There was no effect on endothelial dysfunction or arterial stiffness after exposure. © 2022 The Author(s).
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| 32. |
- Stroh, Emilie, et al.
(author)
-
Stadsluftens hälsobelastning på barn
- 2022. - 5
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Reports (other academic/artistic)abstract
- Resultaten från denna studie tyder på påtagliga skillnader för de barn som växer upp i större städer jämfört med barn som växer upp ruralt eller i medelstora/mindre orter när det kommer till exponering för luftföroreningar samt den faktiska inandade dosen av dessa. Barn vid förskolor i Malmö exponeras för nästan dubbelt så höga nivåer partikulära luftföroreningar (PM2,5) jämfört med barn vid förskolorna utanför Malmö. Denna skillnad i exponering är även tydlig för den dos av partiklar som barnen bedöms andas in, där barnen i Malmö i genomsnitt, andas in en dubbelt så hög dos varje minut som barnen på förskolorna utanför Malmö. Motsvarande exponeringstrend går även att se för sot och kvävedioxider där barnens exponering för sot i Malmö oftast är dubbelt så hög och deras exponering för kvävedioxid kunde vara upp till tre gånger så hög som för förskolebarnen utanför Malmö. Det är dock viktigt att här poängtera att ingen av förskolorna i studien överskred rådande miljökvalitetsnormer eller miljömålet ”Frisk Lufts” gränsvärden. Sett till WHO:s skärpta riktlinjer för luftföroreningar överskrider däremot tre av fem förskolor i Malmö samt förskolan i Staffanstorp gränsvärdet avseende PM2,5 och tre av fem förskolor i Malmö överskrider också gränsvärdet avseende kvävedioxider. Resultaten från studien tyder även på att exponeringen på några av förskolorna, främst i Malmö, skulle kunna minskas genom att schemalägga barnens vistelsetid utomhus till tidpunkter då emissioner och trafikintensitet kring förskolorna och deras gårdar är lägre. Dock riskerar detta att ytterligare begränsa Malmöbarnens möjligheter till att vistas utomhus vilken redan ligger 20% lägre i genomsnitt jämfört med barnen på förskolorna utanför Malmö. Studien visar också att urbana mätstationer och gaturumsmätningar kan både över- och underskatta uppmätta halter på barnens förskolegårdar vilket är viktigt att ha i åtanke vid planering av barns utemiljöer i större städer samt belyser behovet av att inte enbart förlita sig på generella mätningar och modelleringar.
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| 33. |
- Stroh, Emelie, et al.
(author)
-
Stadsluftens hälsobelastning på barn
- 2022
-
Reports (other academic/artistic)abstract
- På uppdrag av Naturvårdsverket har avdelningen för Arbets- och miljömedicin vid Lunds universitettillsammans med Institutionen för Ergonomi och Aerosolteknologi vid Lunds tekniska högskola utfört enstudie i Skåne vilken som syftar till att ta reda på skillnaden, när det kommer till faktisk inandad dos avluftföroreningar, mellan barn som växer upp i större städer (Malmö) och barn som växer upp imedelstora/mindre och landsbygdsnära orter.Resultaten tyder på att det finns påtagliga skillnader för de barn som växer upp i stora städer jämförtmed barn som växer upp i medelstora/mindre orter när det kommer till tid spenderad utomhus påförskolans gård samt deras exponering för luftföroreningar och den inandade dosen av dessa.Barnen på de trafikexponerade förskolorna i Malmö var ute betydligt kortare tid men andades in endubbelt så hög dos av partiklar/minut jämfört med barnen på förskolorna i de mindre ochlandsbygdsnära orterna. Tre av förskolorna i Malmö överskrider också WHO:s gränsvärden förkvävedioxid (årsmedel) under sina respektive mätveckor.Studien visar också att urbana mätstationer och gaturumsmätningar kan både över- och underskattauppmätta halter på barnens förskolegårdar vilket är viktigt att ha i åtanke vid planering av barnsutemiljöer i större städer samt belyser behovet av att inte enbart förlita sig på generella mätningar ochmodelleringar.
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| 34. |
- Vasilatou, K., et al.
(author)
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Extending traceability in airborne particle size distribution measurements beyond 10 µm : Counting efficiency and unit-to-unit variability of four aerodynamic particle size spectrometers
- 2023
-
In: Aerosol Science and Technology. - : Taylor and Francis Ltd.. - 0278-6826 .- 1521-7388. ; 57:1, s. 24-34
-
Journal article (peer-reviewed)abstract
- The aim of this study was to establish traceable number concentration measurements of airborne particles beyond 10 μm in particle size. To this end, the primary standards for particle number concentration at the National Metrology Institutes of Switzerland and Japan were further developed to extend their measurement capabilities. Details on the upgraded setup are provided. An inter-comparison of the two primary standards using an optical particle counter as transfer standard showed that these agree well within the stated uncertainties at polystyrene (PS) equivalent optical diameter of 15 µm. Subsequently, four Model 3321 (TSI Inc., USA) aerodynamic particle size spectrometers (APS) were calibrated against the primary standard of Switzerland using size-certified PS spheres with optical/aerodynamic diameter up to 20 µm as test aerosols. The counting efficiency profile and unit-to-unit variability of the APS units were determined. The results presented here can be useful for the analysis and interpretation of data collected by the different atmospheric aerosol networks worldwide. The outlined methodology can also be applied in the calibration of automated bio-aerosol monitors. © 2022 The Author(s).
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| 35. |
- Ziegler, Ann Kathrin, et al.
(author)
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Dietary fatty acids modulate oxidative stress response to air pollution but not to infection
- 2024
-
In: Frontiers in Physiology. - : Frontiers Media SA. - 1664-042X. ; 15
-
Journal article (peer-reviewed)abstract
- Anthropogenic changes to the environment expose wildlife to many pollutants. Among these, tropospheric ozone is of global concern and a highly potent pro-oxidant. In addition, human activities include several other implications for wildlife, e.g., changed food availability and changed distribution of pathogens in cities. These co-occurring habitat changes may interact, thereby modulating the physiological responses and costs related to anthropogenic change. For instance, many food items associated with humans (e.g., food waste and feeders for wild birds) contain relatively more ω6-than ω3-polyunsaturated fatty acids (PUFAs). Metabolites derived from ω6-PUFAs can enhance inflammation and oxidative stress towards a stimulus, whereas the opposite response is linked to ω3-derived metabolites. Hence, we hypothesized that differential intake of ω6-and ω3-PUFAs modulates the oxidative stress state of birds and thereby affects the responses towards pro-oxidants. To test this, we manipulated dietary ω6:ω3 ratios and ozone levels in a full-factorial experiment using captive zebra finches (Taeniopygia guttata). Additionally, we simulated an infection, thereby also triggering the immune system’s adaptive pro-oxidant release (i.e., oxidative burst), by injecting lipopolysaccharide. Under normal air conditions, the ω3-diet birds had a lower antioxidant ratio (GSH/GSSG ratio) compared to the ω6-diet birds. When exposed to ozone, however, the diet effect disappeared. Instead, ozone exposure overall reduced the total concentration of the key antioxidant glutathione (tGSH). Moreover, the birds on the ω6-rich diet had an overall higher antioxidant capacity (OXY) compared to birds fed a ω3-rich diet. Interestingly, only the immune challenge increased oxidative damage, suggesting the oxidative burst of the immune system overrides the other pro-oxidative processes, including diet. Taken together, our results show that ozone, dietary PUFAs, and infection all affect the redox-system, but in different ways, suggesting that the underlying responses are decoupled despite that they all increase pro-oxidant exposure or generation. Despite lack of apparent cumulative effect in the independent biomarkers, the combined single effects could together reduce overall cellular functioning and efficiency over time in wild birds exposed to pathogens, ozone, and anthropogenic food sources.
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