Evaluation of African Dust Events and Effect on PM₁₀ Concentration in Tunisia

In this study, we applied a current method following the European guidelines for the demonstration and subtraction of PM₁₀ excess attributable to natural sources under the Directive 2008/50/EC. The calculation of the Saharan dust contribution to the daily PM₁₀ concentration in the considered stations has been obtained in several steps. First, we have determined the daily PM₁₀ concentration measured in each station during the events as well as the regional background represented by 50 percentiles of the PM₁₀ series measured 15 days before and 15 days after the Saharan dust event recommended by the European guidance of the natural source contribution. Then, we have quantified the contribution of Saharan dust to PM₁₀ concentration in the considered sites by the subtraction of these two terms. The anthropogenic daily PM₁₀ concentration in each considered station has been determined by subtracting the Saharan dust contribution from the daily concentration registered during the intrusion