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- Andersen, Christina, et al.
(författare)
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Inhalation and dermal uptake of particle and gas phase phthalates - A human chamber exposure study
- 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 have exposed sixteen test subjects to particle and gas phase phthalates in the controlled chamber exposure study. Deuterium labelled phthalates were used to generate particle D4-DEHP (di(2-ethylhexyl) phthalate) and gas phase D4-DEP (diethyl phthalate) for exposures scenarios allowed studying the dermal only and combined inhalational and dermal uptake. Metabolites were measured in urine samples before and after three hours of exposure. The inhalation was the dominant route of uptake for both DEHP and DEP in this study design and exposure settings. Larger uptake of DEP compared to DEHP both via inhalation and dermal uptake was observed. Dermal uptake of DEHP was not observed in this study. Inhalational urinary excretion factors of the metabolites were found to be 0.73 for DEHP and 0.53 for DEP. This study also highlights the importance of taking into consideration the deposited dose of inhaled particles in studies of uptake of particles.
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| 2. |
- Andersen, Christina, et al.
(författare)
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Inhalation and Dermal Uptake of Particle and Gas-phase Phthalates - A Human Exposure Study
- 2018
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Ingår i: Environmental Science & Technology. - : American Chemical Society (ACS). - 1520-5851 .- 0013-936X. ; 52:21, s. 12792-12800
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Tidskriftsartikel (refereegranskat)abstract
- Phthalates are ubiquitous in indoor environments, which raises concern about their endocrine disrupting properties. However, studies of human uptake from airborne exposure are limited. We studied the inhalation uptake and dermal uptake by air-to-skin transfer with clean clothing as a barrier of two deuterium-labelled airborne phthalates: particle-phase D4-DEHP (di-(2-ethylhexyl)phthalate) and gas-phase D4-DEP (diethyl phthalate). Sixteen participants, wearing trousers and long-sleeved shirts, were under controlled conditions exposed to airborne phthalates in four exposure scenarios: dermal uptake alone, and combined inhalation+dermal uptake of both phthalates. The results showed an average uptake of D4-DEHP by inhalation of 0.0014±0.00088 (µg kg-1 bw)/(µg m-3)/h. No dermal uptake of D4-DEHP was observed during the 3 hour exposure with clean clothing. The deposited dose of D4-DEHP accounted for 26% of the total inhaled D4-DEHP mass. For D4-DEP, the average uptake by inhalation+dermal was 0.0067±0.0045 and 0.00073±0.00051 (µg kg-1 bw)/(µg m-3)/h for dermal uptake. Urinary excretion factors of metabolites after inhalation were estimated to 0.69 for D4-DEHP and 0.50 for D4-DEP. Under the described settings, the main uptake of both phthalates was through inhalation. The results demonstrate the differences in uptake of gas and particles, and highlights the importance of considering the deposited dose in particle uptake studies.
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| 5. |
- Dierschke, Katrin, et al.
(författare)
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Acute respiratory effects and biomarkers of inflammation due to welding-derived nanoparticle aggregates
- 2017
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Ingår i: International Archives of Occupational and Environmental Health. - : Springer Science and Business Media LLC. - 0340-0131 .- 1432-1246. ; 90:5, s. 451-463
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Tidskriftsartikel (refereegranskat)abstract
- Welders are exposed to airborne particles from the welding environment and often develop symptoms work-related from the airways. A large fraction of the particles from welding are in the nano-size range. In this study we investigate if the welders' airways are affected by exposure to particles derived from gas metal arc welding in mild steel in levels corresponding to a normal welding day. In an exposure chamber, 11 welders with and 10 welders without work-related symptoms from the lower airways and 11 non-welders without symptoms, were exposed to welding fumes (1 mg/m(3)) and to filtered air, respectively, in a double-blind manner. Symptoms from eyes and upper and lower airways and lung function were registered. Blood and nasal lavage (NL) were sampled before, immediately after and the morning after exposure for analysis of markers of oxidative stress. Exhaled breath condensate (EBC) for analysis of leukotriene B4 (LT-B4) was sampled before, during and immediately after exposure. No adverse effects of welding exposure were found regarding symptoms and lung function. However, EBC LT-B4 decreased significantly in all participants after welding exposure compared to filtered air. NL IL-6 increased immediately after exposure in the two non-symptomatic groups and blood neutrophils tended to increase in the symptomatic welder group. The morning after, neutrophils and serum IL-8 had decreased in all three groups after welding exposure. Remarkably, the symptomatic welder group had a tenfold higher level of EBC LT-B4 compared to the two groups without symptoms. Despite no clinical adverse effects at welding, changes in inflammatory markers may indicate subclinical effects even at exposure below the present Swedish threshold limit (8 h TWA respirable dust).
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| 6. |
- Gren, Louise, et al.
(författare)
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Lung function and self-rated symptoms in healthy volunteers after exposure to hydrotreated vegetable oil (HVO) exhaust with and without particles
- 2022
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Ingår i: Particle and Fibre Toxicology. - : Springer Science and Business Media LLC. - 1743-8977. ; 19:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Diesel engine exhaust causes adverse health effects. Meanwhile, the impact of renewable diesel exhaust, such as hydrotreated vegetable oil (HVO), on human health is less known. Nineteen healthy volunteers were exposed to HVO exhaust for 3 h in a chamber with a double-blind, randomized setup. Exposure scenarios comprised of HVO exhaust from two modern non-road vehicles with 1) no aftertreatment system ('HVOPM+NOx' PM1: 93 mu g-m(-3), EC: 54 mu g-m(-3), NO: 3.4 ppm, -NO2: 0.6 ppm), 2) an aftertreatment system containing a diesel oxidation catalyst and a diesel particulate filter ('HVONOx' PM1: similar to 1 mu g-m(-3), NO: 2.0 ppm, -NO2: 0.7 ppm) and 3) filtered air (FA) as control. The exposure concentrations were in line with current EU occupational exposure limits (OELs) of NO, -NO2, formaldehyde, polycyclic aromatic hydrocarbons (PAHs), and the future OEL (2023) of elemental carbon (EC). The effect on nasal patency, pulmonary function, and self-rated symptoms were assessed. Calculated predicted lung deposition of HVO exhaust particles was compared to data from an earlier diesel exhaust study. Results: The average total respiratory tract deposition of PM1 during -HVO(PM+ NO)x was 27 mu g-h(-1). The estimated deposition fraction of HVO PM1 was 40-50% higher compared to diesel exhaust PM1 from an older vehicle (earlier study), due to smaller particle sizes of the -HVOPM+ NOx exhaust. Compared to FA, exposure to -HVOPM+ NOx and -HVONOx caused higher incidence of self-reported symptoms (78%, 63%, respectively, vs. 28% for FA, p < 0.03). Especially, exposure to -HVOPM+ NOx showed 40-50% higher eye and throat irritation symptoms. Compared to FA, a decrement in nasal patency was found for the -HVONOx exposures (- 18.1, 95% CI: - 27.3 to - 8.8 L-min(-1), p < 0.001), and for the -HVOPM+ NOx (- 7.4 (- 15.6 to 0.8) L -min(-1), p = 0.08). Overall, no clinically significant change was indicated in the pulmonary function tests (spirometry, peak expiratory flow, forced oscillation technique). Conclusion: Short-term exposure to HVO exhaust concentrations corresponding to EU OELs for one workday did not cause adverse pulmonary function changes in healthy subjects. However, an increase in self-rated mild irritation symptoms, and mild decrease in nasal patency after both HVO exposures, may indicate irritative effects from exposure to HVO exhaust from modern non-road vehicles, with and without aftertreatment systems.
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| 7. |
- Isaxon, Christina, et al.
(författare)
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A Novel System for Source Characterization and Controlled Human Exposure to Nanoparticle Aggregates Generated During Gas–Metal Arc Welding
- 2013
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Ingår i: Aerosol Science and Technology. - : Informa UK Limited. - 1521-7388 .- 0278-6826. ; 47:1, s. 52-59
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Tidskriftsartikel (refereegranskat)abstract
- Abstract in Undetermined The aim of this study was to achieve a method to perform detailed characterization and human exposure studies of nanosized and nanostructured aerosol particles. The source chosen was mild steel, active gas, arc welding fume. The setup consisted of a generation chamber, where welding can be performed, connected to an airtight stainless steel 22 m(3) exposure chamber. Instrumentation, consisting of a tapered element oscillating microbalance, a scanning mobility particle sizer, and a sampler for electron microscopy and particle-induced X-ray emission analysis was connected to the stainless steel chamber. The feasibility of the system for human exposure studies was evaluated by exposing 31 human volunteers, in groups of three, to a test aerosol containing 1 mg/m(3) welding fumes and to conditioned, filtered air. The results show that an aerosol that accurately represents dilute welding fume exposures that occur in workplaces can be produced in a controlled manner, and that the experimental setup can be used for 6 h, double-blind, exposures of human subjects. Particle mass concentration levels could be varied from <5 mu g/m(3) to more than 1000 mu g/m(3). Fumes from metal active gas welding showed a unimodal size distribution with a mean mobility diameter of 160 nm, transmission electron microscopy showed aggregates with a clearly nanosized structure.
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| 8. |
- Isaxon, Christina, et al.
(författare)
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Realistic indoor nano-aerosols for a human exposure facility
- 2013
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Ingår i: Journal of Aerosol Science. - : Elsevier BV. - 0021-8502. ; 60, s. 55-66
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to achieve realistic levels of two different types of aerosols commonly abundant in indoor environments in an experimental chamber intended for human exposure studies and aerosol characterization. The aerosols chosen were particles from candle lights (in particle number dominated by inorganic water soluble particles) and from ozone-terpene reactions (organic particles). The aerosol generation and characterization system consisted of a controlled air tight stainless steel 22 m(3) chamber, to which the generation set-ups were connected. No air could enter or leave the chamber except through a conditioning system by which temperature, relative humidity and air exchange rate could be controlled. Candle smoke aerosol was generated from ten candles burning in a 1.33 m(3) glass and stainless steel chamber. The aerosol was diluted by clean air from the conditioning system before entering the chamber. Terpene vapor was generated by passing pure nitrogen through a glass bottle containing limonene oil. Ozone was generated by a spark discharge using pure O-2, and was added to the ventilation air flow downstream the inlet for terpene vapors and upstream the inlet to the chamber. Both aerosols were characterized with respect to number and mass concentrations, size distribution and chemical composition. Particle number concentration in the size range 10-650 nm could be varied from <10 cm(-3) to more than 900,000 cm(-3) (for candle smoke) or to more than 30,000 cm(-3) (for particles formed in a 160 ppb terpene/40 ppb ozone mixture). Furthermore, the set-ups were evaluated by, for each source, repeating the generation at six three-hour long events. For both aerosols repeatable generations at pre-determined concentration levels, that were stable over time, could be achieved. The results show that realistic concentrations of aerosols from real-world environments could be reproduced in a well-controlled manner and that this set-up could be used both for aerosol characterization and for human exposures. (C) 2013 Elsevier Ltd. All rights reserved.
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