Heavy metal contamination of soil and vegetation in the vicinity of industries in Bangladesh

A study was conducted to investigate the heavy metal contamination of soil and vegetation in the vicinity of industries around Dhaka city in Banglades h. Categorically soils, grass (Cynoden doctylon L), water hyacinth (Eichhor nia crassipes L), rice (Oryza sative L), and arum (Alocasia esculenta L) we re collected from tannery, ceramic, textile dying and sulphuric acid produc ing industrial sites. The concentrations of total Cd, Cu, Mn, Ni, Pb and Zn ranged from 0.1-1.8, 28-217, 106-577, 25-112, 17-99 and 53-477 mg kg(-)1 s oil, respectively among the industrial sites. The concentrations of some he avy metals ranged from background levels to levels in excess of tolerable l imits in agricultural soils. The concentrations of total Cu, Mn, Ni, Pb and Zn decreased with increasing distance from the disposal points of the tann ery and the textile dying industries. Cadmium, Cu, Mn, Ni, Pb and Zn showed highly significant (p < 0.01) positive correlations with their total and D TPA-extractable contents in soils. The concentrations of most heavy metals were also higher in the vegetation samples of tannery area and the content of Pb (13-45 mg kg(-1)) in grass samples exceeded the toxic limit. In corre lation matrix, plant concentrations of Cu, Mn, Pb and Zn were significantly correlated with their total and extractable contents in soils.