| 1. |
- Laursen, K. R., et al.
(författare)
-
Airway and systemic biomarkers of health effects after short-term exposure to indoor ultrafine particles from cooking and candles - A randomized controlled double-blind crossover study among mild asthmatic subjects
- 2023
-
Ingår i: Particle and Fibre Toxicology. - 1743-8977. ; 20:1
-
Tidskriftsartikel (refereegranskat)abstract
- BackgroundThere is insufficient knowledge about the systemic health effects of exposure to fine (PM2.5) and ultrafine particles emitted from typical indoor sources, including cooking and candlelight burning. We examined whether short-term exposure to emissions from cooking and burning candles cause inflammatory changes in young individuals with mild asthma. Thirty-six non-smoking asthmatics participated in a randomized controlled double-blind crossover study attending three exposure sessions (mean PM2.5 & mu;g/m(;)(3) polycyclic aromatic hydrocarbons ng/m(3)): (a) air mixed with emissions from cooking (96.1; 1.1), (b) air mixed with emissions from candles (89.8; 10), and (c) clean filtered air (5.8; 1.0). Emissions were generated in an adjacent chamber and let into a full-scale exposure chamber where participants were exposed for five hours. Several biomarkers were assessed in relation to airway and systemic inflammatory changes; the primary outcomes of interest were surfactant Protein-A (SP-A) and albumin in droplets in exhaled air - novel biomarkers for changes in the surfactant composition of small airways. Secondary outcomes included cytokines in nasal lavage, cytokines, C-reactive protein (CRP), epithelial progenitor cells (EPCs), genotoxicity, gene expression related to DNA-repair, oxidative stress, and inflammation, as well as metabolites in blood. Samples were collected before exposure start, right after exposure and the next morning.ResultsSP-A in droplets in exhaled air showed stable concentrations following candle exposure, while concentrations decreased following cooking and clean air exposure. Albumin in droplets in exhaled air increased following exposure to cooking and candles compared to clean air exposure, although not significant. Oxidatively damaged DNA and concentrations of some lipids and lipoproteins in the blood increased significantly following exposure to cooking. We found no or weak associations between cooking and candle exposure and systemic inflammation biomarkers including cytokines, CRP, and EPCs.ConclusionsCooking and candle emissions induced effects on some of the examined health-related biomarkers, while no effect was observed in others; Oxidatively damaged DNA and concentrations of lipids and lipoproteins were increased in blood after exposure to cooking, while both cooking and candle emissions slightly affected the small airways including the primary outcomes SP-A and albumin. We found only weak associations between the exposures and systemic inflammatory biomarkers. Together, the results show the existence of mild inflammation following cooking and candle exposure.
|
|
| 2. |
- Laursen, K. R., et al.
(författare)
-
An RCT of acute health effects in COPD-patients after passive vape exposure from e-cigarettes
- 2021
-
Ingår i: European Clinical Respiratory Journal. - : Informa UK Limited. - 2001-8525. ; 8:1
-
Tidskriftsartikel (refereegranskat)abstract
- Background: E-cigarette use has been shown to have short-term acute effects among active users but less is known of the acute passive effects, particularly among individuals with existing respiratory diseases. Objective: To investigate local and systemic effects of short-term passive vape exposure among patients with mild or moderate chronic obstructive pulmonary disease (COPD). Methods: In a double-blinded crossover study 16 non-smoking COPD-patients (mean age 68) were randomly exposed for 4 h to passive vape (median PM2.5: 18 mu g/m(3) (range: 8-333)) and clean air (PM2.5 < 6 mu g/m(3)) separated by 14 days. Particles were measured using an ultrafine particle counter (P-TRAK) and a scanning mobility particle sizer (SMPS). Health effects including Surfactant Protein-A (SP-A) and albumin in exhaled air, spirometry, FeNO, and plasma proteins were evaluated before, right after, and 24 hours after exposure. Participants reported symptoms throughout exposure sessions. Data were analyzed using mixed models. Results: SP-A in exhaled air was negatively affected by exposure to vape and several plasma proteins increased significantly. Throat irritation was more pronounced during passive vape exposure, while FVC and FEV1 decreased, however, not significantly. Conclusions: SP-A in exhaled air and some plasma proteins were affected by passive vape in patients with COPD indicating inflammation, showing that passive vape exposure is potentially harmful.
|
|
| 3. |
- Detlef, Henrieka, et al.
(författare)
-
Seasonal sea-ice in the Arctic's last ice area during the Early Holocene
- 2023
-
Ingår i: Communications Earth & Environment. - : Springer Science and Business Media LLC. - 2662-4435. ; 4:1
-
Tidskriftsartikel (refereegranskat)abstract
- According to climate models, the Lincoln Sea, bordering northern Greenland and Canada, will be the final stronghold of perennial Arctic sea-ice in a warming climate. However, recent observations of prolonged periods of open water raise concerns regarding its long-term stability. Modelling studies suggest a transition from perennial to seasonal sea-ice during the Early Holocene, a period of elevated global temperatures around 10,000 years ago. Here we show marine proxy evidence for the disappearance of perennial sea-ice in the southern Lincoln Sea during the Early Holocene, which suggests a widespread transition to seasonal sea-ice in the Arctic Ocean. Seasonal sea-ice conditions were tightly coupled to regional atmospheric temperatures. In light of anthropogenic warming and Arctic amplification our results suggest an imminent transition to seasonal sea-ice in the southern Lincoln Sea, even if the global temperature rise is kept below a threshold of 2 °C compared to pre-industrial (1850–1900).
|
|
| 4. |
- Graham, Emelie Linnéa, 1989-
(författare)
-
Insights into key processes governing atmospheric aerosol loadings and their interactions with clouds
- 2022
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Aerosol particles are ubiquitous in the atmosphere and an essential part of the atmospheric radiation balance regulating the Earth’s temperature. Aerosol-cloud interaction still remains the largest single uncertainty in future climate projections. In addition, aerosols are also responsible for air pollution, causing severe health effects. With various origins and short atmospheric lifetimes, aerosols are unevenly distributed in the atmosphere, making simulations of air pollution and future climate scenarios challenging. This thesis aims to improve the understanding of the physical and chemical processes that govern aerosol concentration in the atmosphere, using both field as well as laboratory experiments.Field measurements were performed at a remote station at Mt Åreskutan, central Sweden. Located at 1250 m a.s.l. the station is frequently covered by clouds, allowing for in-cloud measurements. Aerosol particle size distribution measurements revealed a shift towards smaller diameters in the ambient aerosol size distribution after the station had been within a cloud. This is a result of the larger (> 60 nm) particles being more effectively scavenged by clouds as compared with the smaller end of the size distribution. Chemical analysis revealed a similar composition of the cloud water as the particulate matter, suggesting that cloud droplet activation at Mt Åreskutan is primarily dependent on particle size, and the aerosol population to have been internally mixed. Similarly, measurement of hygroscopicity and volatility revealed similar water-solubility and evaporation behaviour for the ambient aerosols and cloud residuals, with the organic fraction representative of aged boreal secondary organic aerosol (SOA) and showing no signs of significant aqueous phase processing.The NArVE laboratory campaign took place in an atmospheric simulation chamber at Paul Scherrer Institute, Switzerland. The experiments traced nitrate-induced SOA formation and ageing of three biogenic precursors, namely α-pinene, isoprene, and β-caryophyllene, using mass spectrometric techniques and evaporation measurements. The volatility of α-pinene SOA from nitrate oxidation was found to be higher than the corresponding ozonolysis products. The nitrate oxidation of isoprene resulted in species with similar volatility to α-pinene, while the β-caryophyllene system produced lower volatility compounds then the other two precursors. Quantitative comparison of the volatility measurements to commonly-used theoretical parameterizations revealed the need for further studies of the impact of the nitrate functional group on molecular volatility. Dark ageing of α-pinene was found to mainly occur through particle phase oxidation forming less volatile species. During the photolysis related to sunrise the molecular composition changed towards more volatile species, while no significant evaporation could be observed for the α-pinene and isoprene systems.A common theme in all these studies was investigating the level of detail needed to theoretically describe the observations. We found that while simple approximations (such as internal mixing and size-independent chemical composition of the particles) are often sufficient to capture trends in atmospheric aerosol properties, more research on (1) the processes taking place on shorter time- and smaller size scales than investigated here and (2) the effects of nitrate group on molecular volatility are warranted.
|
|
