The environmental impacts of heavy metals in soil, certain plants and wastewater near industrial area of Brahmanbaria, Bangladesh

At various locations around the world, environments are now becoming greatly polluted by heavy metals, while damage is being done to soil and aquatic life with serious implications for humanity as well. Once heavy metals enter the ecosystem, they persist for a long time, and they are very difficult to eliminate. Discharging of industrial wastes enriched with heavy metals substantially pollutes the soil, water, and air. This study investigated the levels of heavy metals around the industrial area of Brahmanbaria, which is located in Chittagong Division, Bangladesh. Samples of soil, wastewater, vegetable, and grass were collected from the industrial area. The heavy metals were quantified using atomic absorption spectroscopy. The heavy metals found in soil were chromium (Cr) 8.2–18.8, lead (Pb) 3.5–18.3, copper (Cu) 4.6–10.8, zinc (Zn) 48.5–273.4, nickel (Ni) 10.06–26.9, and cadmium (Cd) 0.2 mg/kg, respectively. The metal contents in the wastewater were Cr 0.03–0.5, Pb 0.01–0.05, Cu 0.01–0.02, Zn 0.6–11.2, Ni 0.03–0.14, and Cd 0.003 mg/L, respectively. The metal contents in vegetable and grass were Cr 81.5–247.8, Pb 10.3–34.1, Cu 5.5–6.3, Zn 419.8–435.3, and Ni 8.7–15.5 mg/kg, respectively. The amount of metal in the soil, wastewater, and vegetables and grass followed the sequences: Zn > Cr > Ni > Pb > Cu > Cd, Zn > Cr > Ni > Pb > Cu > Cd, and Zn > Cr > Pb > Ni > Cu, respectively. Compared to the WHO guidelines, the soil in the study area was not polluted with Pb, Cu, and Cd but was moderately polluted with Cr, Zn, and Ni. Continual accumulation of metals in the soil, vegetables and grass could pose a serious risk to the environment as well as many life forms.