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WHAT ARE THE CHARACTERISTICS OF AIRBORNE PARTICLES THAT WE ARE EXPOSED TO? Focus on Indoor Environments and Emissions from Biomass Fired District Heating

Wierzbicka, Aneta LU (2008)
Abstract
Ambient fine particulate matter PM2.5 (particles with a diameter smaller than 2.5 μm) has been associated with cardiovascular and respiratory morbidity and mortality. It has been shown that biomass burning for heat production purposes can generate large amounts of fine particles. Thus characteristics of particle emissions from biofuel combustion may be important in the assessment of health effects. This is especially significant as the use of biofuels is increasing. There is a growing concern about exposure to airborne particles in indoor environments, as it has become apparent that indoor sources periodically can generate particles that in mass and number concentrations frequently exceed ambient levels. Considering also that we spend... (More)
Ambient fine particulate matter PM2.5 (particles with a diameter smaller than 2.5 μm) has been associated with cardiovascular and respiratory morbidity and mortality. It has been shown that biomass burning for heat production purposes can generate large amounts of fine particles. Thus characteristics of particle emissions from biofuel combustion may be important in the assessment of health effects. This is especially significant as the use of biofuels is increasing. There is a growing concern about exposure to airborne particles in indoor environments, as it has become apparent that indoor sources periodically can generate particles that in mass and number concentrations frequently exceed ambient levels. Considering also that we spend about 90% of our time in indoor environments, information on particle characteristics found in indoors is of great importance. Detailed characterisation of particles found both indoors and outdoors is of interest for epidemiological and toxicological studies and in guiding the development of control strategies.



This research characterises airborne particles found in various Swedish indoor environments: two schools, a supermarket, a restaurant, an apartment and a house. It presents the detailed physical and chemical properties of candle smoke particles as an example of a typical indoor source. Research results also provide insight into the characteristics of particles emitted from district heating units operating on solid biofuels.



Continuous particle measurements in conjunction with log books of the occupants’ activities enabled identification of indoor sources of particles, which mainly comprise different types of cooking, burning candles, burning incense, air fresheners and cleaning products (possibly due to terpenes-ozone reactions). This study confirms that indoor sources can greatly elevate indoor particle levels especially in residences with low air exchange rates (AER). Indoor sources periodically increased photometer readings by a factor of up to 20 compared with outdoor levels, while increased particle number concentrations were up to 26 times higher than outdoor concentrations. Source strengths attained in this study could be used for general modelling of indoor particle concentrations. Indoor particle characteristics may be useful for the assessment of possible health effects.



The importance of an adequate ventilation system that is capable of diluting/removing and not allowing the accumulation of particles generated by indoor sources becomes apparent. This needs to be emphasised especially in the light of efforts to make residential houses energy efficient, which is frequently done at the expense of reduced AER. It is not possible to regulate activities in private homes. Thus in order to reduce exposure to indoor particles, efforts should be made to enclose spaces and enhance ventilation in locations where strong indoor sources of particles occur, namely in the kitchen. Raising general public awareness should be one of the priorities.



It was shown that in all the studied boilers combusting biofuels, large amounts of fine particles containing heavy metals (e.g. Zn, Cd, Cr, Pb) were being emitted to the atmosphere even though these district heating units meet current mass concentration emission limit requirements. The results obtained are best suited for air pollution modelling, which in turn allows the assessment of possible health and environmental impacts. The obtained particle emission characteristics, together with the results on collection efficiencies of the abatement techniques used may prove useful for the optimisation of combustion technologies and the development of efficient emission control measures. (Less)
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author
supervisor
opponent
  • Prof. Marijnissen, Jan, Delft University of Technology, The Netherlands
organization
publishing date
type
Thesis
publication status
published
subject
keywords
particles, indoor environments, biomass combustion
pages
169 pages
defense location
Stora hörsalen, Ingvar Kamprad Designcentrum, Sölvegatan 26, Lund
defense date
2008-04-25 10:15
ISBN
978-91-628-7443-8
language
English
LU publication?
yes
id
5d713a6e-1432-4ca4-a59a-8a892785c39b (old id 1051101)
date added to LUP
2008-03-31 13:03:26
date last changed
2016-09-19 08:45:16
@phdthesis{5d713a6e-1432-4ca4-a59a-8a892785c39b,
  abstract     = {Ambient fine particulate matter PM2.5 (particles with a diameter smaller than 2.5 μm) has been associated with cardiovascular and respiratory morbidity and mortality. It has been shown that biomass burning for heat production purposes can generate large amounts of fine particles. Thus characteristics of particle emissions from biofuel combustion may be important in the assessment of health effects. This is especially significant as the use of biofuels is increasing. There is a growing concern about exposure to airborne particles in indoor environments, as it has become apparent that indoor sources periodically can generate particles that in mass and number concentrations frequently exceed ambient levels. Considering also that we spend about 90% of our time in indoor environments, information on particle characteristics found in indoors is of great importance. Detailed characterisation of particles found both indoors and outdoors is of interest for epidemiological and toxicological studies and in guiding the development of control strategies.<br/><br>
<br/><br>
This research characterises airborne particles found in various Swedish indoor environments: two schools, a supermarket, a restaurant, an apartment and a house. It presents the detailed physical and chemical properties of candle smoke particles as an example of a typical indoor source. Research results also provide insight into the characteristics of particles emitted from district heating units operating on solid biofuels.<br/><br>
<br/><br>
Continuous particle measurements in conjunction with log books of the occupants’ activities enabled identification of indoor sources of particles, which mainly comprise different types of cooking, burning candles, burning incense, air fresheners and cleaning products (possibly due to terpenes-ozone reactions). This study confirms that indoor sources can greatly elevate indoor particle levels especially in residences with low air exchange rates (AER). Indoor sources periodically increased photometer readings by a factor of up to 20 compared with outdoor levels, while increased particle number concentrations were up to 26 times higher than outdoor concentrations. Source strengths attained in this study could be used for general modelling of indoor particle concentrations. Indoor particle characteristics may be useful for the assessment of possible health effects. <br/><br>
<br/><br>
The importance of an adequate ventilation system that is capable of diluting/removing and not allowing the accumulation of particles generated by indoor sources becomes apparent. This needs to be emphasised especially in the light of efforts to make residential houses energy efficient, which is frequently done at the expense of reduced AER. It is not possible to regulate activities in private homes. Thus in order to reduce exposure to indoor particles, efforts should be made to enclose spaces and enhance ventilation in locations where strong indoor sources of particles occur, namely in the kitchen. Raising general public awareness should be one of the priorities. <br/><br>
<br/><br>
It was shown that in all the studied boilers combusting biofuels, large amounts of fine particles containing heavy metals (e.g. Zn, Cd, Cr, Pb) were being emitted to the atmosphere even though these district heating units meet current mass concentration emission limit requirements. The results obtained are best suited for air pollution modelling, which in turn allows the assessment of possible health and environmental impacts. The obtained particle emission characteristics, together with the results on collection efficiencies of the abatement techniques used may prove useful for the optimisation of combustion technologies and the development of efficient emission control measures.},
  author       = {Wierzbicka, Aneta},
  isbn         = {978-91-628-7443-8},
  keyword      = {particles,indoor environments,biomass combustion},
  language     = {eng},
  pages        = {169},
  school       = {Lund University},
  title        = {WHAT ARE THE CHARACTERISTICS OF AIRBORNE PARTICLES THAT WE ARE EXPOSED TO? Focus on Indoor Environments and Emissions from Biomass Fired District Heating},
  year         = {2008},
}