Saharan dust contributions to atmospheric aerosols in Malta

Abstract

Particulate matter has a significant association to critical human health risks. European countries are well known to experience several episodes originating from Saharan dust episodes throughout the year that pose a risk to human health as well as lead to natural exceedances for the PM10 Daily Limit Value (DLV) of 50 µg/m3. As a result of this, Member States have been given the possibility to deduct contribution of natural sources from the measured PM10 values. This European Commission (2011) has established guidelines that Member States are expected to comply with for the deduction to be possible. By consulting the data compiled by the Maltese entity, the Environment and Resources Authority (ERA), it was possible to analyse the Saharan dust contribution from 2016 to 2020. The three stations that measure PM10 which were used for this study were Għarb, Gozo (rural background site), Msida, Malta (traffic site) and Żejtun, Malta (urban background site). Quantification of Saharan dust contribution from these three stations helped in analysing the spatial consistency across the Maltese islands. A combination of methods was put together for this research to be possible including the use of regimes, backward trajectories using HYSPLIT, and dust forecast models to help identify the dates that experienced Saharan dust episodes across the Maltese islands. Apart from the pairwise comparison between Għarb and Msida in 2019, overall, the Saharan dust contribution can be considered as very close to being identical with no statistical difference between the three stations across Malta. The results help address the limited information about this phenomenon and the importance of more awareness about the Saharan dust implications to human health.