HEAVY METAL CONTAMINATION OF SOIL AND VEGETATION FROM TANNING INDUSTRIES IN BANGLADESH
Kamrun Nahar* and Qafeal Ahsan
Leather industry plays an important role in the economy of Bangladeshi due to its large potential for employment, growth and export. At the same time, it poses serious environmental threats, as in the last few decades the dumping of solid wastes directly into surrounding areas without proper treatment lowered regional environmental quality. The study was conducted at the vicinity of pre-industrial area at Hazaribagh and relocated area at Savar Tannery Estate. Due to improper waste management at Hazaribagh and Savar Tannery Estate (STE), the wastes from the tannery industries and heavy metal contaminated with the solid waste directly on the surrounding land causing potential health hazards in the long term. In dry season soil and plant samples were collected from the industrial sites at different selective sampling points and analyzed to determine the concentration of heavy metals in soil and plant relation occurring by the tanneries. The concentration of Lead (Pb), Chromium (Cr), Iron (Fe) and Cadmium (Cd) were determined by Atomic Absorption Spectrophotometer (AAS). It was found that the concentration of Pb, Cr and Cd at Hazaribagh soils were 40.5 mg/kg, 1.9 mg/kg and 0.45 mg/kg whereas the concentration of Pb and Cr at STE soils were 3.63 mg/kg and 21.28mg/l respectively. Both the sample sites were below the permissible Limit. Fe was not detected in any of the sites and Cd was within permissible limit at Hazaribagh, although the metal was not detected at STE. But in case of plants grown in the mentioned sites exhibit variations and above the permissible limit due to bioaccumulation of metals. The content of Pb and Cr in Spinacia oleracea at Hazaribagh are 3.78 mg/kg and 73.05 mg/kg respectively compare to Amaranthus spinosus at STE were 5.16 mg/kg and 24.82 mg/kg. Being above the permissible limit of FAO & WHO, 2011 the content of Pb was higher at STE and Cr was found remarkably higher and toxic, if consumed by human at Hazaribagh compare to STE.
Keywords: Heavy Metals, Tannery Industry, Industrial Waste, Bioaccumulation, Spectrophotometer.
[Full Text Article]