Bioaccumulation of water-born heavy metal lead in freshwater mussel, Anodonta cygnea (Bivalvia; Unionidae)

Heavy metals are considered as a hazardous group of water pollutants that have high potential of toxicity in aquatic organisms. The present study was conducted to investigate the absorption and accumulation of lead (Pb) in foot, mantle and gills of freshwater mussel, Anodonta cygnea. Bivalves were exposed to the sub-lethal concentration of 125 μg/L of Pb for 9 days and the basal Pb content in unexposed mussels, accumulation content and values of bioaccumulation factor (BAF) of the those  exposed were measured in days of 3, 6 and 9. There was no significant difference in basal levels of Pb in the studied organs. Pb contents in the exposed mussels were significantly (P<0.05) increased during exposure period in all organs. Accumulation levels on day 9 in foot (10.82±4.5 μg/g DW) and gills (10.02±1.69 μg/g DW) were significantly (P<0.05) higher than mantle (5.15±2.8 μg/g DW). BAF showed a significant increase (P<0.05) during the exposure period in all organs and BAF values for the mantle were significantly (P<0.05) lower than other organs. Based on the results, absorption and bioaccumulation of Pb as a non-essential element in A. cygnea has different trends in different organs.