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The Toxicity of Organotin Compounds on Acetes Intermedious in Kaohsiung Harbor AreaHsu, Tien-Chi 27 August 2003 (has links)
Kaohsiung harbor is the biggest one in Taiwan. Many previous researches revealed that the pollution of organotin was usually serious in harbors. TBT contained in the antifouling paint of vessels would release into the seawater and contaminate the harbor area. In this study, shrimps (Acetes intermedius) and water samples were collected from Xinbin wharf and the second port entrance in Kaohsiung harbor. After pretreatment, ethylated with sodium tetraethylborate and extracted by hexanes, contents of organotin compounds were analyzed by GC-FPD.
The results showed that TBT and DBT were the predominant
organotin species in Kaohsiung harbor. In seawater, the concentration of DBT ( 98-257 ng/L ) was higher than TBT ( 17-133 ng/L). In shrimps, the concentration of TBT ( 228-480 ng/g ) was higher than DBT ( 98-257 ng/g). The concentration of TBT in shrimps decreased with the increased wet weight. There was no significant variation for the organotin concentrations in the shrimp samples collected from the second port entrance during the period from September 2002 to May 2003.
The bioconcentration factor (BCF) of TBT ranged between 6700-17900. The organotin concentrations in shrimps collected from Xinbin wharf also showed no significant variation from August 2002 to May 2003. The BCF values of TBT were between 2200-8300. The ability of shrimps to concentrate organotin compounds was between that of fishes and neogastropods. There were significant differences for the organotin concentrations in shrimps sampled from different sampling area. The shrimps sampled from Kaohsiung harbor were significantly higher in organotin concentration than Tungkang. According to the risk assessment, shrimps from Tungkang were much lower than the tolerable daily intake, however, the shrimps from Kaohsiung harbor were well beyond the dangerous level .
In order to understand the toxicity of organotin compounds to the shrimps, experiments on acute toxicity test were conducted. The 72-h LC50 of TBT was 47£gg/L. After toxicity test, live shrimps which were exposed to organotin for 72 hours were assayed. The concentration of TBT in shrimps increased with the exposure concentrations. DBT which was the degradation product of TBT also showed the same trend. The 72-h LC50 of DBT was 225£gg/L. After toxicity test period, the concentration of DBT and its metabolite MBT in shrimps also increased with the increased exposure concentrations.
The accumulation rate of the shrimps at 30£gg/L TBT was 17ng/g-h and the elimination rate was 8.8 ng/g-h. The accumulation rate of the shrimps at 100£gg/L DBT was 12 ng/g-h and the elimination rate was 4.2 ng/g-h.
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