Impact of industrial and traffic changes on atmospheric dust and trace element deposition in Didouche Mourad, Algeria

Given the critical environmental and health implications of atmospheric deposition, this study examined the long-term variations in atmospheric dust and trace element deposition in Didouche Mourad, Algeria, from 21/6/2002–20/6/2003 (P1) to 21/12/2017–20/12/2018 (P2), a period marked by significant industrial and infrastructural changes. Using a network of 10 sampling sites, we conducted two-year-long measurement campaigns to quantify the deposition rates of dust and seven trace elements (Pb, Mn, Cr, Ni, Cu, Co, and Cd). We used a combination of techniques, including spatiotemporal analysis and enrichment factor calculations, to understand how local changes affect air quality. The results showed a substantial reduction in the average cross-site deposition rates between the two periods: dust (61 %), Co (98 %), Cd (97 %), Pb (90 %), Mn (76 %), Cu (62 %), Ni (51 %), and Cr (50 %). This improvement was attributed to specific interventions, including new road construction and upgraded industrial filtration systems. Shifts in seasonal deposition patterns were observed, with elevated levels in summer and autumn during 2002–2003, changing to peaks in summer and winter in 2017–2018. Four main pollution sources were identified through PCA for each period: agricultural activity (P1), soil dust (P2), Saharan dust (P1, P2), vehicular emissions (P1), cement plant (P2), and industrial processes (P1, P2). This study provides crucial insights into the long-term effectiveness of air quality management strategies in industrial areas and offers a model for assessing and mitigating atmospheric pollution in similar global settings. The comprehensive approach and extended timeframe of this study significantly contribute to our understanding of the complex dynamics of atmospheric deposition in evolving urban-industrial environments.