Determination of Some Heavy Metals in the Soils of Schools Playground in Riyadh City, Saudi Arabia PDF

Keywords

Heavy Metals. Soil Contamination, ICP-MS, Schools Playgrounds, Riyadh, Saudi Arabia

Abstract

The determination of the total content of fifteen elements in soil samples collected from 29 different schools playgrounds in Riyadh metropolitan environment was carried out by inductively coupled plasma mass spectrometry (ICP-MS) combined with microwave digestion technique. According to the results of the concentration at 29 schools' playgrounds in the selected districts, the average of the metals were determined at 25.91, 29.36, 147.73, 8.02, 17.45, 9.92, 43.72, 2.83, 0.64, 0.5, 0.12, 0.92, 0.45, 27.95, and 1.04 mg/kg (dry soil) for V, Cr, Mn, Co, Ni, Cu, Zn, As, Mo, Ag, Cd, Sn, Sb, Pb, and U, respectively. Most school playgrounds with elevated heavy metals concentrations were found in Manfuhah, Al Shifa, Al Yamamah, Sultanah, An Namuthajiyah, Al Wurud and Al Shamaisi residential districts due to their proximity to main traffic roads, industrial areas, and high density residential areas. On the other hand, schools playgrounds with lower heavy metals levels were found in An Nuzhah, Al Aqiq and Al Jazirah residential districts, which may be attributed to less traffic emissions, low residential density, and their distant location from the industrial areas. The measured concentrations levels of the heavy metals in the soil, except for Pb, were below the allowable concentration limits. The Pb concentration exceeded these limits in Manufuhah school playground, The enrichment coefficient values (Mobs /Mcrust) for V, Cr, Mn, Co, Ni, and Cu were less than unity at 0.32,0.47, 0.25, 0.51,0.44, and 0.36, respectively, suggesting that the origin of these elements is mostly the local soil. The enrichment coefficient values for Zn and Pb were more than unity at 1.66 and 8.47, respectively. suggesting that these elements are anthropogenic in origin, for example, from the traffic emissions.