Assessing the depth-wise distribution of heavy metals in soil can provide valuable insights into the extent of enrichment, contamination, and the possible sources of pollutants. A study was conducted in parts of Patancheru Industrial areas of Hyderabad, India to assess the vertical distribution of heavy metal content in soil, focusing on enrichment, contamination, and pollutant sources. Sixty soil samples from 15 sites, spanning four depths (0–15 cm, 15–30 cm, 30–50 cm, 50–100 cm) were analyzed for total Fe, Mn, Zn, Cu, Pb, Cr, Co and Ni concentrations. The concentrations of Fe, Mn, Zn, Cu, Pb, Cr, Co, and Ni, regardless of the study depths and sites, range from 2570–10,667, 22.5–439, 11.6–47.2, 3.47–14.2, 5.53–31.7, 36.0–63.1, 2.99–17.5 to 10.5–47.3 mg kg−1respectively. The mean concentrations of all the measured heavy metals showed minor variation across depths, except for Zn and Pb. Moreover, the mean concentration of all the measured heavy metals at various soil depths was within the threshold or target limits except for total Ni. At certain sampling depths and locations, Ni content exceeded the permissible threshold of 35 mg kg−1 in the soil. Surface soils (0–15 cm) exhibited moderate to significant enrichment of Pb, Zn, Cr, and Co. The enrichment factor for the overall Pb concentration varies from 3.02 to 24.73, indicating a range of moderate to very high enrichment throughout the soil depths. Following Pb, Cr exhibits enrichment levels ranging from 2.31 to 9.35, while Co ranges from 1.07 to 5.58.The sites within the study area varied in contamination levels, spanning from moderate contamination to a slight degree of pollution, as assessed by the contamination/pollution index of each element. Principle component analysis and enrichment factor values show that Cu originated primarily from natural sources; while Pb and Cr were likely to be anthropogenic to purely anthropogenic and Zn, Mn, Ni, and Co had both crustal and like to be anthropogenic origins. The maximum and minimum ecological risk index (ERI) values were recorded for Pb and Zn content, respectively. The maximum PERI value of 15.8 was recorded in the study area, indicating a low ecological risk level. However regular monitoring of the heavy metal concentration in soils is recommended over the study area to maintain a low level of ecological risk via reclamation interventions.
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