行政院國家科學委員會專題研究計畫期中進度報告:台灣烏腳病地區養殖魚類砷累積之生態毒物模擬(2/3)

The objective of our work in the second year is to
determine the organ-specific toxicokinetics and
dose-responses of arsenic (As) burdens in tilapia. We
linked kinetically an AUC-based acute toxicity model and
a pharmacodynamic model to derive dose-response
relationships between equilibrium organ-specific As
concentrations and mortality effects. The 7-d exposure
test revealed that the highest bioconcentration factor
(BCF) is found in the stomach and the lowest one is in
the muscle, and the values are 9.56 and 1.04, respectively.
The order of BCF was stomach > intestine > liver > gill >
muscle. The 7-d acute toxicity bioassay showed that 24
and 96-h LC50 for tilapia exposed to As are 69.06 and
28.68 mg L-1, respectively. Dose-response relationships
followed the refined Hill equation indicated that that the
muscle, gill and liver have a relative steep sigmoid
dose-response profile in that IEC50 are 26.6, 62.5 and
78.5 µg g-1 dry wt, respectively. We suggested that the
gill could be used as a surrogate in site-specific risk
assessment.