Anthropogenic particle dispersions in topsoils of the Middle Nile Delta: a preliminary study on the contamination around industrial and commercial areas in Egypt

摘要

Increased industrialization has adversely affected various components of the environment including soil, which is the ultimate site of settling and accumulation of fly ash. Fine respirable size particles in the atmosphere are detrimental to human health and their ultimate accumulation in the soil leads to soil pollution. In this study, these particles were identified, quantified and subjected to intensive analysis by SEM/EDX. Accordingly, the physical and chemical characteristics, the origin and the pathway of such particulates are documented for the Middle Nile Delta using the magnetic susceptibility as proxy for the industrial emissions. The average bulk density of magnetic spherules varies between 4.4 +/- 0.7, 4.8 +/- 0.9 and 5.4 +/- 0.6 g/cm(3) for the >125, 63-125 and 36-63 mu m fractions, respectively, and consists predominantly of iron oxides with variable amounts of Ti, Si, Mn, Mg, Al, Ca, Cr and Cu. Their attached grains and adhesive materials are commonly composed of various contents of Si, Al, Fe, Ca, P, Zn, Ba and S depending on their origin. The results indicated that most surface soil samples are enhanced magnetically than the natural local background magnetic signal due to atmospherically deposited urban dust. The industrial sites are characterized by highest average magnetic susceptibility value (47 x 10(-5) m(3)g(-1)) combined with highest concentration of magnetic spherules (66 sph.g(-1)). Moreover, the residential area surrounding industrial zones-particularly those located in the windblown (SE) direction-is seriously affected by industrial dust. This study provides a database to evolve strategies for remedial measures to minimize environmental degradation.