Saharan dust levels in Greece and received inhalation doses

Abstract

Abstract. The desert of Sahara is one of the major sources of mineral dust on Earth, producing around 2×108 tons/yr. Under certain weather conditions, dust particles from Saharan desert get transported over the Mediterranean Sea and most of Europe. The limiting values set by the directive EC/30/1999 of European Union can easily be exceeded by the transport of desert dust particles in all south European areas and especially urban. In this study, the effects of dust transport on air quality in several Greek urban areas are quantified. PM10 concentration values from stationary monitoring stations are compared to dust concentrations for the 4-year period 2003–2006. The dust concentration values in the Greek areas were estimated by the SKIRON modelling system coupled with embedded algorithms describing the dust cycle. The mean annual dust contribution to daily-averaged PM10 concentration values was found to be around or even greater than 10% in the urban areas throughout the years examined. Natural dust transport may contribute by much more than 20% to the annual number of exceedances – PM10 values greater than EU limits – depending on the specific monitoring location. In a second stage of the study, the inhaled lung dose received by the residents in various Greek locations is calculated. The particle deposition efficiency of mineral dust at the different parts of the human respiratory tract is determined by applying a lung dosimetry numerical model, which incorporates inhalation dynamics and aerosol physical processes. The inhalation dose from mineral dust particles was greater in the upper respiratory system (extrathoracic region) and less significant in the lungs, especially in the sensitive alveolar region. However, in cases of dust episodes, the amounts of mineral dust deposited along the human lung are comparable to those received during exposure in heavily polluted urban or smoking areas.

The representation of dust transport and missing urban sources as major issues for the simulation of PM episodes in a Mediterranean area

“…We showed that it originated in the long-range transport of African dust, confirming that outbreak phenomena can influence particle levels in southern France even under the form of moderate episodes. This result is in agreement with the observations reported for other Mediterranean countries (Rodriguez et al, 2001(Rodriguez et al, , 2002Querol et al, 2009;Mitsakou, 2008). Although the CHIMERE model was able to reproduce the nature and the timing of this episode, we show that the use of climatological values to determine the amount of dust transferred to the domain from the larger scale are insufficient to reproduce the amplitude of the event.…”

Variability in regional background aerosols within the Mediterranean

“…The main distinctive feature of PM at the three sites of this study is the relatively high levels of the crustal component (4 and 1 µg/m 3 for PM 10 and PM 2.5 at MSY; 14 and 2 (0.8 if the major 6 dust events are removed) µg/m 3 for PM 10 and PM 1 at FKL; and 9, and 1 µg/m 3 for PM 10 and PM 2.5 at ERL, respectively) when compared with the selected central and northern European sites (2 and <0.5 µg/m 3 for PM 10 and PM 2.5 in most cases). The accessional year round con- tribution of dust at FKL is estimated to be 8±5 µgPM 10 /m 3 , in agreement with the range given by Mitsakou et al (2008) (5-9 µg/m 3 ) for Heraklion, the nearest large city to FKL station. Of course, at the remote site of FKL the percentage contribution of dust is much higher than at Heraklion reaching 40-50% in spring (frequent dust outbreaks) and winter (some of which are among the most intense events).…”

Saharan dust impact in central Italy: An overview on three years elemental data records

“…However, these tools alone are in general not sufficient as the transit of air masses coming from Sahara does not necessarily imply high PM concentrations at ground level. A modelbased method has been proposed by Mitsakou et al (2008) to estimate the contribution of desert dust to PM10 in Greece, while other approaches focused on the analysis of PM10 concentration time sequences (Ganor et al, 2009). During the last decade several papers appeared in the literature concerning the desert dust contribution to PM in Spain (see for example Rodriguez et al, 2001;Escudero et al, 2005Escudero et al, , 2007Querol et al, 2009).…”