Bioaccumulation of the estrogenic compound 4-nonylphenol in the clam Tapes philippinarum.

Despite the widespread use of nonylphenol ethoxylates (NPEs) in many household and industrial detergents and their accumulation in aquatic environments, mostly as nonylphenol (NP), very few data are available about bioaccumulation of NP in bivalves. Considering that NP can exert estrogenic effects in marine organisms, it is of great concern to improve the knowledge on their capability of bioaccumulating the contaminant. In the present study, bioaccumulation of 4-NP was evaluated in the clam Tapes philippinarum after exposure for 7 and 14 days to 0, 0.025, 0.05, 0.1, and 0.2 mg NP/L. NP concentrations were also determined before and after water renewal in the experimental tanks. NP concentrations measured after water renewal ranged from 52% to 96% of the nominal concentrations, whereas the values fell to 20–59 % after 24 h. NP was not detected (DL = 0.05 mg/kg FW) in control clams. The highest NP concentration (180.12 mg/kg FW) was measured in the clams exposed for 7 days to 0.2 mg NP/L. In the clams exposed to the lowest NP concentrations in water (0.025 and 0.05 mg/L), accumulation of NP was not completed in 7 days, whereas NP tissue concentrations observed in 0.1 and 0.2 mg NP/L-exposed clams after 7 days of exposure were maintained after 14 days. The bioconcentration factor (BCF), calculated using the mean NP water concentration, ranged from 1098, for the clams exposed for 7 days to 0.025 mg NP/L, to 1918, for the clams exposed for 14 days to 0.05 mg NP/L.