Saharan dust levels in Greece and received inhalation doses

[摘要] 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, dustparticles from Saharan desert get transported over the Mediterranean Sea andmost of Europe. The limiting values set by the directive EC/30/1999 ofEuropean Union can easily be exceeded by the transport of desert dustparticles in the south European Region and especially in urban areas, wherethere is also significant contribution from anthropogenic sources. In thisstudy, the effects of dust transport on air quality in several Greek urbanareas are quantified. PM₁₀ concentration values from stationarymonitoring stations are compared to dust concentrations for the 4-yearperiod 2003–2006. The dust concentration values in the Greek areas wereestimated by the SKIRON modelling system coupled with embedded algorithmsdescribing the dust cycle. The mean annual dust contribution todaily-averaged PM₁₀ concentration values was found to be around or evengreater than 10% in the urban areas throughout the years examined.Natural dust transport may contribute by more than 20% to the annualnumber of exceedances – PM₁₀ values greater than EU limits – dependingon the specific monitoring location. In a second stage of the study, theinhaled lung dose received by the residents in various Greek locations iscalculated. The particle deposition efficiency of mineral dust at thedifferent parts of the human respiratory tract is determined by applying alung dosimetry numerical model, which incorporates inhalation dynamics andaerosol physical processes. The inhalation dose from mineral dust particleswas greater in the upper respiratory system (extrathoracic region) and lesssignificant in the lungs, especially in the sensitive alveolar region.However, in cases of dust episodes, the amounts of mineral dust depositedalong the human lung are comparable to those received during exposure inheavily polluted urban or smoking areas.

[学科分类] 大气科学