1 research outputs found
Zebrafish (<i>Danio rerio</i>) Eleutheroembryo-Based Procedure for Assessing Bioaccumulation
This
paper reports on the development and preliminary evaluation
of a new bioaccumulation test based on the use of zebrafish <i>(Danio renio)</i> eleutheroembryos (72 h after hatching, corresponding
to 144 h post fertilization, hpf) as an alternative to adult fish-based
procedures for regulatory purposes regarding REACH application. The
proposed test accomplished the OECD 305 guideline and consists of
a 48 h uptake period followed by a 24 h depuration step. Bioaccumulation
experiments were performed for a selected of hyper hydrophobic chemicals
(log <i>K</i><sub>ow</sub>> 7.6), that is, PCB 136 and
PBDE
154 at two concentration levels corresponding roughly to 1% and 0.1%
the chemicaĺs LC<sub>50</sub>(nominal concentrations of 4.0
and 12.0 μg/L for PCB 136, and 1.0 and 5.0 μg/L PBDE 154,
respectively). Toxicokinetic models were used to calculate the bioconcentration
factors (BCFs) based on of the chemical concentrations found in the
contaminated eleutheroembryos and their surrounding media. The experimentally
determined accumulation profiles show bioaccumulation by zebrafish
eleutheroembryos of both chemicals, and that the process is more complex
than simple water–lipid partition. Calculated log BCFs using
a first-order accumulation model(3.97 and 3.73 for PCB 136, and 3.95
and 4.29 for PBDE 154) were in the range of those previously reported
in the literature. The suitability of this new nonprotected life stage
bioaccumulation protocol for BCF estimation was evaluated by application
to widely divergent micropollutants with different accumulation mechanisms.
The results were compared with those in the MITE-NITE database for
adult rice fish (<i>Oryzias latipes</i>)