Evaluation of heavy metals contamination in soils at Peenya Industrial Area, Bengarulu, India

Abstract

Concentrations of heavy metals were analyzed in the soils to know the metal contamination due to anthropogenic activities in Peenya Industrial Area, Bengarulu, India. Samples were collected from the soil horizon from an industrial area at twelve locations at different depths viz., 0–30 cm, 30–90 cm, and 90–150 cm to understand the soil pollution level due to industrial activities. Heavy metals in the soil were analyzed using ICP-MS X Series-II from M/s. Thermo Fisher Scientific, C-MET, Hyderabad. Analyzed data show that the soil in the industrial area is significantly contaminated with heavy metals than its normal values. Concentration values at 0–30-cm depth for Al ranged from (21647–41,682 mg/kg), As (0–3.90 mg/kg), B (43.88–144.97 mg/kg), Ba (27.06–459.53 mg/kg), Cd (0.22–1.01 mg/kg), Co (7.36–185.71 mg/kg), Cr (14.97–718.13 mg/kg), Cu (1.32–397.60 mg/kg), Fe (11919–72,064 mg/kg), Mn (162.10–1665.82 mg/kg), Mo (0–9.21 mg/kg), Pb (12.62–139.94 mg/kg), Sb (0.48–25.48 mg/kg), Se (0–206.88 mg/kg), Sr (6.19–113.98 mg/kg), Ti (0–0.29 mg/kg), V (16.63–182.62 mg/kg), and Zn (38.81–327.13 mg/kg). Similarly, higher concentration was observed in soil samples collected at 30–90 cm and 90–150 cm depth. Soil contamination was assessed based on index of geoaccumulation (Igeo), enrichment factor (EF), contamination factor (CF), degree of contamination (Cdeg), modified degree of contamination (mCdeg), pollution load index (PLI), ecological risk factor (ER), potential ecological risk index (RI), toxic units (TU), and principal component analysis (PCA). The high values of these indices/factors obtained for soil samples revealed considerable heavy metal pollution due to improper waste management practices within the industrial area. A contaminated site possesses a significant impact on human, terrestrial, and aquatic ecosystems. The comparison was made with the other soil areas from India, Asia, and worldwide. Mobility of heavy metals in groundwater and soil has been discussed in the article.