Persistence of heavy metals and human health risk assessment in the South Indian industrial area

The present study provided a comprehensive evaluation of heavy metal contamination from soil to groundwater and the associated risk to human health in an industrial area situated in Telangana state, South India. Soils at three depth levels (0, 20, and 80 cm) and groundwater samples at 32 locations have been collected in the area. The samples have been analyzed for trace metals (Mn, B, Zn, Cr, Pb, Ni, Hg, Cd, and As) to understand the heavy metal contamination. Furthermore, geo-accumulation (I-geo) of heavy metals, contamination factor, pollution index, and human health risks due to prolonged exposure to contaminated water are estimated. The results indicated that soils are moderately contaminated at 18.5, 25.9, 7.4, 14.8, and 7.1% of locations by B, Zn, Cr, Pb, Ni, and Cd, respectively, as per I-geo at 80-cm depth. However, the contamination factor indicated that 14.8% of the locations were contaminated by Mn and Zn and 7.4, 70.3, 66.6, 74, and 3.7% by B, Cr, Pb, Ni, and Cd, respectively. However, groundwater is only contaminated when groundwater levels are less than 3 m below ground level. The results also indicated higher carcinogenetic health risks if groundwater is used for a longer time.