UPTAKE AND DEPURATION OF POLYCYCLIC AROMATIC-HYDROCARBONS FROM SEDIMENT BY THE ZEBRAFISH (BRACHYDANIO-RERIO)

Zebrafish (Brachydanio rerio) were exposed for 30 d to individual C-14 -labeled polycyclic aromatic hydrocarbons (PAHs) (anthracene, phenanth rene, pyrene, or benzo[a]pyrene) adsorbed on sediment. The uptake and depuration rate constants were measured. Rate of radioactivity release was measured under both contaminated (experiment 1) and clean (experi ment 2) conditions. The results confirm that uptake and depuration rat e constants were strongly related to physicochemical properties. Howev er, the uptake from the water compartment was rapidly decreased in our microcosm system (-83% for anthracene and phenanthrene, -71% for pyre ne, and -59% for benzo[a]pyrene within the first 2 d). For depuration in clean water, the half-lives of radioactivity loss from whole body w ere 63, 97, 115, and 138 h for anthracene, phenanthrene, pyrene, and b enzo[a]pyrene, respectively, and were positively correlated with log K -ow. In experiment 1 after 10 d, the remaining PAH concentrations were only about 16% of the maximum concentrations measured at time 24 h fo r anthracene, 12% for phenanthrene, 30% for pyrene, and 46% for benzo[ a]pyrene. K-ow appears to be a determining factor for partitioning con stants for sorption to sediment, uptake, and release in aquatic organi sms.