PM10 temporal variation and multi-scale contributions of sources and meteorology in Sfax, Tunisia

Abstract

The study of PM10 temporal variation for two successive years (2009 and 2010), carried out at the proximity of a crossroad (≈ 41,390 vehicles per day) located in an urban centre in Sfax, Tunisia, showed comparable annual average concentrations (≈ 80 μg/m3). However, monthly and daily average concentration levels have been significantly variable. Moreover, the monthly average concentration levels have revealed almost similar tendencies to those observed in other Mediterranean regions, signalling the highest ones between winter and spring periods. High PM10 concentration levels, including the winter-spring peak, have been more significant due to the Saharan wind circulation. Complementary statistical approaches, concerning the simple linear regression, the factorial analysis of correspondences, the quality of representation, and the hierarchical cluster analysis, have revealed the simultaneous impact of local sources and extreme meteorological conditions on highly registered PM10 concentrations, particularly in the presence of an obstacle such as buildings. The investigation of Air Quality Health Index (AQHI) has exhibited that more than 60% of the period in focus has been characterized by good-to-fair air quality for the ordinary people. The remainder has been characterized by poor to very poor air quality for the same kind of people. Furthermore, more than 70% of the whole period has been found unhealthy for sensitive groups, hindering them from any outdoor activities.