Heavy metal concentrations in water from Bakkhali River estuary, Cox’s Bazar, Bangladesh

Abstract

Heavy metals contamination of water is considered as severe global issues for developing countries like Bangladesh. Because heavy metal pollution ruined aquatic ecosystem especially fish diversity which contribute important share on economy of a country. The present study designed to investigate the contamination level of lead (Pb), chromium (Cr), cadmium (Cd), copper (Cu) and zinc (Zn) in surface water of Bakkhali river estuary in Bangladesh. The decreasing order of metals concentration was Cu>Zn >Cr>Pb>Cd with the mean value of 2.6> 0.825 > 0.355 > 0.056 >0.003 mg/L, respectively. The results showed a significant seasonal variation of heavy metals concentration in water. Higher contamination occurred during post monsoon, while lower during the monsoon season. Among the all studied heavy metals Cu concentration was higher (2.6 mg/L) and lower (0.003 mg/L) concentration was Cd. Metal concentrations in water samples exceeded the safe limits of drinking water which indicated that the water from this estuarine river is not fully safe for using/drinking. The study area was not entirely polluted in terms of all metal concentrations. But level of metal concentration in polluted sites supposed risk to ecological health. The findings of present study recommended that continuous monitoring of water should be aimed to evaluate the risk which could help to maintain healthy coastal ecosystem and improve management strategy of this estuarine river.