Assessment of heavy metals concentration in water and Tengra fish (Mystus vittatus) of Surma River in Sylhet region of Bangladesh

The study was carried out to assess the concentration of heavy metals in water and Tengra fish (Mystus vittatus) of the Surma River, the largest water basin ecosystem covering the north-eastern parts of Bangladesh. Water and Tengra fish (M. vittatus) samples were collected from a total of six sampling stations in which three sampling stations were in Sylhet district and the rest three were in Sunamganj district. Samples were collected from February 2017 to June 2017 on a monthly basis. Water and Tengra fish (M. vittatus) samples were analyzed for the detection of heavy metals viz., lead (Pb), chromium (Cr) and cadmium (Cd) concentrations. Atomic absorption spectrophotometry was used for the detection of heavy metals after digestion of the samples. Pb and Cr were detected from both water and Tengra fish (M. vittatus) samples collected from all the six sampling stations of Sylhet and Sunamganj district. But, Cd was not found both in water and Tengra fish (M. vittatus) during the study period. This study concluded that the detected concentrations of metals (Pb and Cr) in the studied Tengra fish (M. vittatus) muscles were accepted by the international legislation limits and are safe for human consumption. But in water, Pb is the only metal that potentially poses the ecological risk to the water body as it exceeds the acceptance level recommended by World Health Organization (WHO). Consequently, close monitoring of metals pollution of the Surma River is recommended with a view to minimizing the health risk of the population that depend on the river for their water and fish supply

Screening of organochlorine insecticides (DDT and heptachlor) in dry fish available in Bangladesh

The concentrations of organochlorine insecticides DDT and heptachlorwere investigated to estimate the current status of insecticidesused in dry fish. The most popular dry fish– ribbon fish (Chhuri),shrimp (Chingri) and bombay duck (Loittya) were selected for thisstudy and these dry fishes were collected from different markets ofDhaka and Chittagong. The range of DDT used in all the samples was3.038 ppb to 874.966 ppb. The range of DDT in ribbon fish 131.611 ppb to 149.430 ppb, in shrimp 3.038 ppb to 318.206 ppb and in bombayduck 61.918 ppb to 874.966 ppb was found. The range of heptachlorused in all the samples was 0.682 ppb to 5.464 ppb. The range ofheptachlor in ribbon fish 1.710 ppb to 2.306 ppb, in shrimp 0.682 ppbto 3.806 ppb and in bombay duck 1.762 ppb to 5.464 ppb was found.The heptachlor was not found in ribbon fish (CTG-2), shrimp (DHK-2and CTG-1) and bombay duck (DHK-1). The concentration of heptachlorin dry fish compare to DDT was found too much less

Location estimation in distributed ad-hoc wireless sensor networks

Abstract not available