Spatial Distribution of the Levels of Trace Metals in Topsoil of Dammam Area, Eastern Province of Saudi Arabia

Abstract

The soil ability to retain toxic trace metals from various sources has proven to be a threat 0to human health and ecological systems, and this necessitates the assessment of the health condition of the soil. The main objective of this study is to produce geochemical maps of trace metals concentration and identify areas of high metal concentration ‘hot spots’ in the topsoil of Dammam area, the Eastern Province of Saudi Arabia. A total of 132 representative topsoil samples were collected from selected Dammam’s residential, industrial, agricultural, and background (reference site) areas and analyzed for their structure and concentration levels of trace metals. The results showed that the mean concentration levels of the trace metals were as follows: Arsenic (As) (1.21±0.69 mg/kg), Barium (Ba) (110.62±262 mg/kg), Cadmium (Cd) (1.18±4.33 mg/kg), Chromium (Cr) (31.79±37.9 mg/kg), Cupper (Cu) (6.76±12.54 mg/kg), Mercury (Hg) (0.08±0.18 mg/kg), Nickel (Ni) (8.95±5.66 mg/kg), Lead (Pb) (6.34±14.55 mg/kg), Titanium (Ti) (119.27±85.74 mg/kg), Vanadium (V) (9.98±6.08 mg/kg), and Zinc (Zn) (23.44±84.43mg/kg). The levels of As, Ba, Hg, Pb, Ni, and V were within the international allowable limits usually found in topsoil, while Cd, Cr, Cu, and Zn exceeded the allowable limits with industrial and residential areas having the highest concentrations. The elevated levels of trace metals in some locations may be attributed to atmospheric deposition and related to activities capable of discharging such pollutants.