Potential ecological risk assessment in soils of Yelagiri hill, Tamil Nadu using energy dispersive X-ray fluorescence (EDXRF) technique

Soil contamination by heavy metals is a serious concern due to their toxicity and ability to accumulate in the environment. The present work explains the assessment of heavy metal contamination in soils of Yelagiri hill, Tamilnadu using energy dispersive X-ray flurascence (EDXRF) technique. Among the determined concentration of heavy metals, the concentration of chromium (Cr-181.9 mg kg^-1) for sample YS-6 is more than twice the average crustal value since possibility of anthropogenic activities. The determined metal concentrations were found in the order of Fe > K > Ca > Ti > Mn > V > Zn > Cr > Ni > Co. In order to assess the pollution status of soil, a potential contamination index (Cp), contamination factor (CF), Contamination degree (Cd), modified contamination degree (mCd), single pollution index (P_i) and nemerow pollution index (NPI) and potential ecological risk factor (E_rⁱ) were estimated to prevent the biological effects on the soil. The calculated values of potential contamination index (Cp), contamination factor (CF), Contamination degree (Cd), modified contamination degree (mCd) suggested that, soil samples are moderately contaminated by metals Ti, V, Cr, Mn, Co due to anthropogenic activities. The calculated values of potential ecological risk factor (E_rⁱ) for Cr, Ni, and Zn is less than 40. This indicates that soil samples are low in ecological risk. Similarly the calculated potential contamination index (RI) value is 26.70 for Cr; 59.96 for Ni; 18.73 for Zn which is less than 95 indicating the soil samples show low potential ecological risk index. The potential ecological risk assessment indicates that living organisms are at no risk of heavy metals.