Ecological risk assessment of heavy metals contamination in agricultural soil from Al Majma'ah, central Saudi Arabia

Abstract

Soil acts as a tank for heavy metals through surface complexation, ion exchange and surface precipitation. The purpose of this study was to assess the contamination and ecological risk of heavy metals (HMs) in agricultural soil in the Al Majma'ah area of central Saudi Arabia. Soil samples from 34 farms were collected, and HMs were evaluated using inductively coupled plasma-atomic emission spectrometry (ICP-AES). Enrichment factor (EF), contamination factor (CF), pollution load index (PLI), and potential ecological risk index (RI) were applied. The average values of the HMs (dry weight, mg/kg) had the following order: Fe > Al > Mn > Zn > Ni > Cr > V > Cu > Pb > Co > As. Results of contamination indices revealed low contamination, low risk and no enrichment for all HMs, except some minor enrichment for Zn and Ni. The considerable positive correlations between all elemental pairings in the correlation matrix and the one extracted principal component suggested that HMs in Al Majmaah soil were formed from weathering of Jurassic to Quaternary sediments in the research area.

Keywords

• Heavy metals
• Risk assessment
• Multivariate analysis
• Agriculture soil
• Saudi Arabia