Abstract:
To assess the environmental degradation, the concentration of heavy metal such as chromium (Cr) in soil samples at various depths of existing tannery area of Hazaribagh, Dhaka, Bangladesh and the proposed tannery industrial area at Tatuljhora, Savar Dhaka, Bangladesh were analyzed by reactor based Neutron Activation Analysis (NAA) method. Arsenic levels in water, soil and herbal at different locations of Sonargaon Upzilla in Narayanganj district, Bangladesh were determined by the same method. The Cr-content at different depths of Hazaribagh area was found in the range of 38 to 33,500 ppm. Higher accumulations were observed in top soil that is above the US permissible level (20 to 85 ppm) except only one sample. The Cr-concentration in soils of Tatuljhora was in the range of 50.9 to 93.6 ppm, which is within the range of chromium background levels reported in worldwide (7 to 221 ppm). Arsenic detected in soil was in the range of 2.06-11.35 ppm. Few water samples contain arsenic above permissible level (0.05 ppm). Surprisingly, arsenic was also found considerably high in some herbals. The arsenic was not found in some herbal corresponding to the water samples where arsenic was not detected. Therefore, some Ayurvedic herbal medicine may be contaminated when they will be prepared with arsenic rich herbs.