Cookstoves, Candles, and Phthalates – Real Time Physicochemical Characterization and Human Exposure to Indoor Aerosols
(2021)- Abstract
- Exposure to air pollution is associated with adverse health effects in humans, with special concern for exposure to fine particulate matter (PM2.5). The physicochemical properties of aerosols impact the health effects. Considering that we spend approximately 90% of our time indoors, it is important to gain increased understanding of indoor aerosol concentrations and properties. The overall aim of the research presented in this thesis was to characterize the physicochemical properties of indoor aerosols from cookstoves, candles, and phthalate sources, and to assess their contribution to human exposure. Aerosol mass spectrometry (AMS) was applied for real time measurements of the aerosol chemical composition and concentration throughout the... (More)
- Exposure to air pollution is associated with adverse health effects in humans, with special concern for exposure to fine particulate matter (PM2.5). The physicochemical properties of aerosols impact the health effects. Considering that we spend approximately 90% of our time indoors, it is important to gain increased understanding of indoor aerosol concentrations and properties. The overall aim of the research presented in this thesis was to characterize the physicochemical properties of indoor aerosols from cookstoves, candles, and phthalate sources, and to assess their contribution to human exposure. Aerosol mass spectrometry (AMS) was applied for real time measurements of the aerosol chemical composition and concentration throughout the measurements included in the thesis.
Emissions from four different cookstoves commonly used in sub Saharan Africa were measured with AMS and interpreted on the basis of a simplified framework describing the thermochemical conversion of biomass. The framework was validated by a correlation analysis of the included emission classes. Moreover, the results showed reduced PM1 emissions for more advanced stoves. However, pollutants which are of specific health concern, were not reduced in proportion to PM1. Even when PM1 emissions were reduced, high emissions of pollutants that have a strong impact on health and climate may be emitted, for example polycyclic aromatic compounds (PAHs) and refractory black carbon (rBC). The framework may be applied to estimate emissions of classes that were not measured in the experiments.
Aerosol emissions from stressed burning of five types of candles of different wax and wick compositions were studied. We found strong variations between the candle types in emissions of PM2.5, BC, and PAHs, as well as strong variations over time, depending on the wax and wick composition. Candle emissions from stressed burning were dominated by BC emissions, with minor contributions from inorganic and organic aerosol emissions. The candles that emitted the lowest BC concentrations showed high emissions of ultrafine particles. NOx, formaldehyde, and gas-phase PAHs showed less variation between candle types and proved difficult to reduce by altering the wax and wick composition. The emissions of particle phase PAHs, BC, and organic aerosol showed strong correlations at the stressed burning of candles, and may be used as proxies for each other.
The sorption of di-(2-ethyhexyl) phthalate (DEHP) on laboratory generated ammonium sulfate particles and indoor air particles was investigated by passing the particles through a 1.2 L chamber equipped with polyvinyl chloride (PVC) flooring. A higher sorption of DEHP to indoor particles, with a higher organic mass fraction, was measured compared to laboratory generated ammonium sulfate particles. In presence of airborne particles the emission of DEHP from PVC flooring increased. Thus, when particles are present in indoor air, the airborne concentration of DEHP available for respiratory deposition may increase. The sorption of DEHP on particles depends on the particle chemical composition. Organic particle concentrations are often high indoors, which promotes the sorption of DEHP and other SVOCs, which in turn may contribute to increased human exposure to DEHP and other SVOCs. This highlights the need to reduce health detrimental chemicals in consumer products and building materials, and to reduce particle concentrations in indoor environments.
A human exposure study was conducted to elucidate the dermal and inhalation uptake in 16 volunteers from exposure to airborne gas- and particle phase phthalates, with participants wearing clean clothing. The uptake was measured, via combined inhalation and dermal air-to-skin transfer and via air-to-skin transfer only for the gas-phase diethyl phthalate (DEP) and for particle phase DEHP. Dermal uptake via air-to-skin transfer only with clean clothing acting as a barrier was ten times lower than the uptake via inhalation for DEP. Only uptake via inhalation was measurable for the particle phase DEHP. DEHP uptake via the skin was below the detection limit. The uptake of the gas-phase DEP via inhalation was four times higher compared to the particle phase DEHP, which reflects the differences in the lung deposition of gases and particles. The physicochemical properties of SVOCs influence their gas-particle partitioning and the likelihood of uptake via both inhalation and the skin, which should be considered in risk assessments of SVOCs.
The results presented in this thesis highlight the importance of detailed physicochemical characterization of indoor aerosols, and the need for a more complete evaluation of their impact on human health.
(Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/9bee882f-7b71-44d0-931a-8583b6a58df8
- author
- Andersen, Christina LU
- supervisor
-
- Joakim Pagels LU
- Aneta Wierzbicka LU
- Axel Eriksson LU
- Annette Krais LU
- opponent
-
- Ass. Prof. Farmer, Delphine, Colorado State University, USA.
- organization
- publishing date
- 2021-04-16
- type
- Thesis
- publication status
- published
- subject
- keywords
- Aerosol particles, OA, BC, cookstoves, candle emissions, phthalates, human exposure, PAHs
- pages
- 84 pages
- publisher
- Division of Ergonomics and Aerosol Technology, Department of Design Sciences Lund University
- defense location
- Lecture hall Stora hörsalen, Ingvar Kamprad Designcentrum IKDC, Sölvegatan 26, Faculty of Engineering LTH, Lund University, Lund.
- defense date
- 2021-05-12 14:15:00
- ISBN
- 978-91-7895-809-2
- 978-91-7895-810-8
- language
- English
- LU publication?
- yes
- id
- 9bee882f-7b71-44d0-931a-8583b6a58df8
- date added to LUP
- 2021-04-15 19:45:40
- date last changed
- 2023-05-04 15:35:51
@phdthesis{9bee882f-7b71-44d0-931a-8583b6a58df8,
abstract = {{Exposure to air pollution is associated with adverse health effects in humans, with special concern for exposure to fine particulate matter (PM2.5). The physicochemical properties of aerosols impact the health effects. Considering that we spend approximately 90% of our time indoors, it is important to gain increased understanding of indoor aerosol concentrations and properties. The overall aim of the research presented in this thesis was to characterize the physicochemical properties of indoor aerosols from cookstoves, candles, and phthalate sources, and to assess their contribution to human exposure. Aerosol mass spectrometry (AMS) was applied for real time measurements of the aerosol chemical composition and concentration throughout the measurements included in the thesis.<br/>Emissions from four different cookstoves commonly used in sub Saharan Africa were measured with AMS and interpreted on the basis of a simplified framework describing the thermochemical conversion of biomass. The framework was validated by a correlation analysis of the included emission classes. Moreover, the results showed reduced PM1 emissions for more advanced stoves. However, pollutants which are of specific health concern, were not reduced in proportion to PM1. Even when PM1 emissions were reduced, high emissions of pollutants that have a strong impact on health and climate may be emitted, for example polycyclic aromatic compounds (PAHs) and refractory black carbon (rBC). The framework may be applied to estimate emissions of classes that were not measured in the experiments.<br/>Aerosol emissions from stressed burning of five types of candles of different wax and wick compositions were studied. We found strong variations between the candle types in emissions of PM2.5, BC, and PAHs, as well as strong variations over time, depending on the wax and wick composition. Candle emissions from stressed burning were dominated by BC emissions, with minor contributions from inorganic and organic aerosol emissions. The candles that emitted the lowest BC concentrations showed high emissions of ultrafine particles. NOx, formaldehyde, and gas-phase PAHs showed less variation between candle types and proved difficult to reduce by altering the wax and wick composition. The emissions of particle phase PAHs, BC, and organic aerosol showed strong correlations at the stressed burning of candles, and may be used as proxies for each other.<br/>The sorption of di-(2-ethyhexyl) phthalate (DEHP) on laboratory generated ammonium sulfate particles and indoor air particles was investigated by passing the particles through a 1.2 L chamber equipped with polyvinyl chloride (PVC) flooring. A higher sorption of DEHP to indoor particles, with a higher organic mass fraction, was measured compared to laboratory generated ammonium sulfate particles. In presence of airborne particles the emission of DEHP from PVC flooring increased. Thus, when particles are present in indoor air, the airborne concentration of DEHP available for respiratory deposition may increase. The sorption of DEHP on particles depends on the particle chemical composition. Organic particle concentrations are often high indoors, which promotes the sorption of DEHP and other SVOCs, which in turn may contribute to increased human exposure to DEHP and other SVOCs. This highlights the need to reduce health detrimental chemicals in consumer products and building materials, and to reduce particle concentrations in indoor environments.<br/>A human exposure study was conducted to elucidate the dermal and inhalation uptake in 16 volunteers from exposure to airborne gas- and particle phase phthalates, with participants wearing clean clothing. The uptake was measured, via combined inhalation and dermal air-to-skin transfer and via air-to-skin transfer only for the gas-phase diethyl phthalate (DEP) and for particle phase DEHP. Dermal uptake via air-to-skin transfer only with clean clothing acting as a barrier was ten times lower than the uptake via inhalation for DEP. Only uptake via inhalation was measurable for the particle phase DEHP. DEHP uptake via the skin was below the detection limit. The uptake of the gas-phase DEP via inhalation was four times higher compared to the particle phase DEHP, which reflects the differences in the lung deposition of gases and particles. The physicochemical properties of SVOCs influence their gas-particle partitioning and the likelihood of uptake via both inhalation and the skin, which should be considered in risk assessments of SVOCs.<br/>The results presented in this thesis highlight the importance of detailed physicochemical characterization of indoor aerosols, and the need for a more complete evaluation of their impact on human health.<br/>}},
author = {{Andersen, Christina}},
isbn = {{978-91-7895-809-2}},
keywords = {{Aerosol particles; OA; BC; cookstoves; candle emissions; phthalates; human exposure; PAHs}},
language = {{eng}},
month = {{04}},
publisher = {{Division of Ergonomics and Aerosol Technology, Department of Design Sciences Lund University}},
school = {{Lund University}},
title = {{Cookstoves, Candles, and Phthalates – Real Time Physicochemical Characterization and Human Exposure to Indoor Aerosols}},
url = {{https://lup.lub.lu.se/search/files/96722229/e_spik_ex_Christina.pdf}},
year = {{2021}},
}