STM Article Repository

Aims: The purpose of this study was to evaluate whether there are any significant toxic effects of the widely exposed metals on different organs (gill, liver, kidney, and muscle) of some commercially important marine fish species (Herpodon nehereus, Pampus chinensis and Hilsa ilisha).

Study Design: The collection of the samples was done from January to March 2018 from Bay of Bengal near Chattogram city of Bangladesh. The study is based on randomly collected samples from the intended sampling sites (Randomized Block Design) to ensure the evenness and unbiases of the collected samples.

Methodology: Analyses were performed for metals such as arsenic (As), lead (Pb) and chromium (Cr) using Atomic Absorption Spectrophotometer (AAS). During each month, five individuals each with three replications from the three targeted species were collected, with a total of 135 (45*3) fishes in the study period.

Results: The concentrations of the metals found in the fishes varied in the following ranges: As: 0.029-0.071 ppm, Pb: 0.008-0.083 ppm and Cr: 0.0001-0.03 ppm. The obtained result revealed the highest concentrations of all three metals were recorded in H.nehereus fish. The organ wise lead concentration was recorded highest in kidneys and gills of examined fishes with significant variation in muscles and liver. The scenario depicted quite differently in case of chromium where concentration in gills was found to be the highest with insignificant variation in accumulation in other three organs. In case of Arsenic, kidneys and livers were the most exposed two organs in comparison to significant exposure to muscles and gills. The obtained values of arsenic accumulation were considered critical for human consumption as it was higher than the recommended values stated by WHO and FAO; but the concentration of lead and chromium were found to be safe for human consumption. The values recorded for lead were increasingly approached to the safety values.

Conclusion: So, crucial steps should be taken regarding safety and environmentally friendly discharge of arsenic and lead; high levels of pollution will not only affect aquatic life but will also invite socio-economic disasters.