| 31. |
- Eriksson, Axel Christian, et al.
(författare)
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Influence of airborne particles' chemical composition on SVOC uptake from PVC flooring - time resolved analysis with aerosol mass spectrometry
- 2020
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Ingår i: Environmental Science & Technology. - : American Chemical Society (ACS). - 1520-5851 .- 0013-936X. ; , s. 85-91
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Tidskriftsartikel (refereegranskat)abstract
- We sampled ammonium sulfate particles and indoor particles of outdoor origin through a small chamber covered with polyvinyl chloride (PVC) flooring. We measured the uptake of semi-volatile organic compounds (SVOC) by the airborne particles in real time. The particles acquired SVOC mass fractions up to 10%. The phthalate ester DEHP (di(2-ethylhexyl)phthalate), a known endocrine disruptor, contributed by approximately half of the sorbed SVOC mass. The indoor particles acquired higher DEHP fraction than laboratory generated ammonium sulfate aerosol. We attribute this increased uptake to absorption by organic matter present in the indoor particles. Using a thermodenuder to remove volatile components, predominantly organics, reduced SVOC uptake. Positive matrix factorization applied to the organic mass spectra suggests that hydrocarbon-like organic aerosol (typically fresh traffic exhaust) sorbs DEHP more efficiently than aged organic aerosol. SVOC uptake is one of the processes that modifies outdoor pollution particles after they penetrate buildings, where the majority of exposure occurs. Particles from indoor sources, typically dominated by organic matter, will undergo such processes as well. Aerosol mass spectrometry improves the time resolution of experimental investigations into these processes, and enables experiments with lower, relevant particle concentrations. Additionally, particle size resolved results are readily obtained.
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| 32. |
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| 33. |
- Eriksson, Axel C., et al.
(författare)
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The role of organic fraction of aerosol particles in uptake of indoor SVOC investigated with real time aerosol mass spectrometry
- 2018
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Ingår i: 15th Conference of the International Society of Indoor Air Quality and Climate, INDOOR AIR 2018. - 9781713826514
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Konferensbidrag (refereegranskat)abstract
- We investigate the uptake of the Di(2-ethylhexyl) phthalate (DEHP) by laboratory generated and ambient aerosol particles passing through a 1.2 liter chamber covered with vinyl flooring on its internal surfaces. We found approximately five times more efficient DEHP uptake on a mass basis by organic particles (ambient particles) compared to laboratory generated salt particles. The increased uptake is likely due to increased adsorption by pre-existing organic aerosol, which is abundant in the ambient aerosol particles. This implies that compounds with adverse health outcomes are added to particles in indoor air after infiltration into buildings via gas-to-particle conversion of indoor generated SVOCs. We show that aerosol mass spectrometry is a suitable tool for highly time-resolved investigations of this process.
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| 34. |
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| 35. |
- Eriksson, Axel, et al.
(författare)
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Diesel soot aging in urban plumes within hours under cold dark and humid conditions
- 2017
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322.
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Tidskriftsartikel (refereegranskat)abstract
- Fresh and aged diesel soot particles have different impacts on climate and human health. While fresh diesel soot particles are highly aspherical and non-hygroscopic, aged particles are spherical and hygroscopic. Aging and its effect on water uptake also controls the dispersion of diesel soot in the atmosphere. Understanding the timescales on which diesel soot ages in the atmosphere is thus important, yet knowledge thereof is lacking. We show that under cold, dark and humid conditions the atmospheric transformation from fresh to aged soot occurs on a timescale of less than five hours. Under dry conditions in the laboratory, diesel soot transformation is much less efficient. While photochemistry drives soot aging, our data show it is not always a limiting factor. Field observations together with aerosol process model simulations show that the rapid ambient diesel soot aging in urban plumes is caused by coupled ammonium nitrate formation and water uptake.
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| 36. |
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| 37. |
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| 38. |
- Eriksson, Axel, et al.
(författare)
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Particulate PAH Emissions from Residential Biomass Combustion : Time-Resolved Analysis with Aerosol Mass Spectrometry
- 2014
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 48:12, s. 7143-7150
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Tidskriftsartikel (refereegranskat)abstract
- Time-resolved emissions of particulate polycyclic aromatic hydrocarbons (PAHs) and total organic particulate matter (OA) from a wood log stove and an adjusted pellet stove were investigated with high-resolution time-of-flight aerosol mass spectrometry (AMS). The highest OA emissions were found during the addition of log wood on glowing embers, that is, slow burning pyrolysis conditions. These emissions contained about 1% PAHs (of OA). The highest PAH emissions were found during fast burning under hot air starved combustion conditions, in both stoves. In the latter case, PAHs contributed up to 40% of OA, likely due to thermal degradation of other condensable species. The distribution of PAHs was also shifted toward larger molecules in these emissions. AMS signals attributed to PAHs were found at molecular weights up to 600 Da. The vacuum aerodynamic size distribution was found to be bimodal with a smaller mode (Dva ~ 200 nm) dominating under hot air starved combustion and a larger sized mode dominating under slow burning pyrolysis (Dva ~ 600 nm). Simultaneous reduction of PAHs, OA and total particulate matter from residential biomass combustion may prove to be a challenge for environmental legislation efforts as these classes of emissions are elevated at different combustion conditions.
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| 39. |
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| 40. |
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