Victoria Aleksandropoulou

Inorganic and Carbonaceous Components in Indoor/Outdoor Particulate Matter in Two Residential Houses in Oslo, Norway

Abstract A detailed analysis of indoor/outdoor physicochemical aerosol properties has been performed. Aerosol measurements were taken at two dwellings, one in the city center and the other in the suburbs of the Oslo metropolitan area, during summer/fall and winter/spring periods of 2002–2003. In this paper, emphasis is placed on the chemical characteristics (water-soluble ions and carbonaceous components) of fine (PM2.5) and coarse (PM2.5–10) particles and their indoor/outdoor relationship. Results demonstrate that the carbonaceous species were dominant in all fractions of the PM10 particles (cut off size: 0.09–11.31 μm) during all measurement periods, except winter 2003, when increased concentrations of water-soluble inorganic ions were predominant because of sea salt transport. The concentration of organic carbon was higher in the fine and coarse PM10 fractions indoors, whereas elemental carbon was higher indoors only in the coarse fraction. In regards to the carbonaceous species, local traffic and secondary organic aerosol formation were, probably, the main sources outdoors, whereas indoors combustion activities such as preparation of food, burning of candles, and cigarette smoking were the main sources. In contrast, the concentrations of water-soluble inorganic ions were higher outdoors than indoors. The variability of water-soluble inorganic ion concentrations outdoors was related to changes in emissions from local anthropogenic sources, long-range transport of particles, sea salt emissions, and resuspension of roadside and soil dusts. In the indoor environment the infiltration of the outdoor air indoors was the major source of inorganic ions.

SPATIAL DISTRIBUTION OF GASEOUS AND PARTICULATE MATTER EMISSIONS IN GREECE

The quantification of air pollutant emissions to theatmosphere, from anthropogenic and natural sources, in Greece is the main focus of the current work. Emissions are spatially and temporally disaggregated in a high resolution grid based on a methodology given in Atmospheric Emissions Inventory Guidebook, CORINAIR. The anthropogenic emissions are equal to those given by UNECE through the EMEP program and an estimation of their spatial distribution in a 5 × 5 km2 grid is performed. Furthermore, natural emissions are calculated using the bottom-up approach and are distributed to the 5 × 5 km2 grid. The methodology used for the estimation of the spatial and temporal distribution of the emissions is presented as well as the contribution of each individual source in the distribution of gaseous and particulate matter emissions in Greece. Energy production, agriculture and road transport have been recognized as the activities in Greece mainly contributing to the anthropogenic emissions. Other important sources include biogenic VOC and resuspended dust.

The effect of dust emissions from open storage piles to particle ambient concentration and human exposure

The current study focus on the determination of dust emissions from piles in open storage yards of a municipal solid waste (MSW) composting site and the subsequent atmospheric dust dispersion. The ISC3-ST (Industrial Source Complex Version 3 - Short Term) model was used for the evaluation of the PM(10) ambient concentrations associated with the dispersion of MSW compost dust emissions in air. Dust emission rates were calculated using the United States Environmental Protection Agency proposed dust resuspension formulation from open storage piles using local meteorological data. The dispersion modelling results on the spatial distribution of PM(10) source depletion showed that the maximum concentrations were observed at a distance 25-75 m downwind of the piles in the prevailing wind direction. Sensitivity calculations were performed also to reveal the effect of the compost pile height, the friction velocity and the receptor height on the ambient PM(10) concentration. It was observed that PM(10) concentrations (downwind in the prevailing wind direction) increased with increasing the friction velocity, increasing the pile height (for distances greater than 125 m from the source) and decreasing the receptor height (for distances greater than 125 m from the source). Furthermore, the results of ISC3-ST were analysed with the ExDoM (Exposure Dose Model) human exposure model. The ExDoM is a model for calculating the human exposure and the deposition dose, clearance, and finally retention of aerosol particles in the human respiratory tract (RT). PM(10) concentration at the composting site was calculated as the sum of the concentration from compost pile dust resuspension and the background concentration. It was found that the exposure to PM(10) and deposited lung dose for an adult Caucasian male who is not working at the composting site is less by 20-74% and 29-84%, respectively, compared to those for a worker exposed to PM concentrations at the composting site.

Development and application of a model (ExDoM) for calculating the respiratory tract dose and retention of particles under variable exposure conditions

The ExDoM is a model for calculating the human exposure and the deposition, dose, clearance, and finally retention of aerosol particles in the respiratory tract at specific times during and after exposure, under variable exposure conditions. Specifically, the model incorporates an exposure module which allows the user to set variable or static exposure conditions (exposure concentration, physical exertion levels, and different environments) or in the case of the physical exertion levels and exposure environment to choose from a list of typical exposure scenarios (activity pattern, exposure environment, and physical exertion level). The exposure concentration can refer to total particulate matter (PM) concentration or chemically resolved particles of variant size distributions. The aerosol size parameters can be introduced to the model either directly as median aerodynamic diameter and geometric standard deviation or are estimated by the model from measurement data. The model treats monodisperse or polydisperse aerosol size distributions. The human respiratory tract (RT) model of the International Commission on Radiological protection (ICRP Publication 66) is utilized for the respiratory tract deposition calculations. The above together with the dose and clearance/retention modules can be used to study together exposure and dose of chemically resolved particles of variant size distributions. The ExDoM model implementation in order to study the exposure and dose of particles in the human RT is demonstrated at two locations. In particular, the dose and retention of particles to RT and the mass transferred to the gastrointestinal tract and blood capillaries are estimated for an adult Caucasian male exposed to PM10 at a coastal remote site in the eastern Mediterranean. In addition, the regional lung doses of specific chemical components of PM10 (inorganic ions and carbonaceous compounds) during realistic exposure conditions outdoors at a residential background area in Oslo, Norway, were assessed. The results from the two studies showed that the dose was enhanced for the carbonaceous fine fraction of particles in the alveolar region of the lung whereas the dose of crustal material dominated in the extrathoracic region.

Particulate Matter Exposure and Dose Relationships Derived from Realistic Exposure Scenarios

Day-averaged outdoor aerosol concentrations from fixed ambient air monitoring stations are associated with the daily lung dose of an individual and the consequent health effects in most studies. The applicability of such measurements for dose assessment is evaluated in this study by comparing the estimated total and regional lung doses using the above concentrations, continuous (hourly) or day-averaged, to the dose derived from actual exposure. Dosimetric calculations are performed using experimentally determined indoor and outdoor concentrations during realistic exposure under variant physical exertion in both environments. The results show that the daily dose can be closely estimated by day-averaged data.