Contribution of natural sources to PM emissions over the metropolitan areas of Athens and Thessaloniki

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

Summarization: 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.Παρουσιάστηκε στο: Air Quality Atmosphere and Healt

Trends in population exposure to particulate matter in urban areas of Greece during the last decade

Summarization: Assessment of population exposure is very important for the evaluation of the adverse health effects of particulate matter (PM) ambient levels. In this work population exposure to PM10 and PM2.5 has been evaluated in outdoor environments in the Athens (AMA) and Thessaloniki (TMA) metropolitan areas during the period 2001–2010. The methodology used is based on combining spatiotemporally allocated PM10 and PM2.5 concentration fields with the geographical distribution of population. The results showed that the number of people living in the AMA exposed to PM10 and PM2.5 concentrations above the annual air quality standards (AQS), has dropped 18% since 2001 and 98% since 2008, respectively. Likewise, in 2010 8% less, compared to 2001, of the AMA population lived in areas where the daily AQS for PM10 was exceeded > 35 times a year. The results as regards TMA indicated a decrease in the number of people exposed to PM10 concentrations over the annual AQS value (78% decrease). However, the number of people living in areas with PM10 concentrations over the daily AQS for > 35 times in a year doubled since 2001. Finally, the spatial distribution of the normalised population load which reflects populated areas with concentrations above the daily AQS was evaluated. The hot spots for both AMA and TMA areas correspond to urban areas and areas with significant primary PM10 emissions.Presented on: Science of the Total Environmen

Particulate matter exposure and dose relationships derived from realistic exposure scenarios

Summarization: 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.Παρουσιάστηκε στο: Indoor Built Environmen