| Summary: | 碩士 === 國立成功大學 === 環境醫學研究所 === 91 === Tritbutyltin and triphenyltin (TBT and TPhT) are used as antifouling paints owing to their strong biocidal activity toward the aquatic organisms such as mollusks. Many studies have showed TBT and TPhT are endocrine disruptors which at very low concentration (1 ng/L in water) will cause “imposex”, the imposition of the male characteristics in females of some gastropods. Organotin compounds can also enter the food chain through bioaccumulation of marine organisms destined for human consumption, such as oyster, farmed salmon, mussels, calms. This study was conducted to determine the concentration of butyltins（BTs）and phenyltins（PhTs）in benthic, offshore and cultured fish in Taiwan in order to understand current contamination levels. Finally, the analytical data and fish uptake data were used to estimate the non-carcinogenic effects expressed as hazard index (HI) for general human population.
Narrow barred Spanish mackerel（Scomberomorus commerson）, red porgy （Pagrus major）, dentex tumifron（Yellowback sea-bream）and milkfish （Chanos chanos）were collected from fishery markets of the northern, southern, eastern and central Taiwan. The organotins in fish were analyzed following the method developed by Iwata et al. with slight modification. The muscle of fish was dried by lyophilization and extract with 0.1% trpolone-acetone, 0.1% trpolone- benzene and hexane saturated acetonitrile. The extract was hexylated with hexylmagnesium bromide as Grignard reagent. The derivative was transferred to 10% benzene-hexane and then passed through Florisil column with 10% benzene-hexane for clean up. A GC/MS was used for organotins determination. The accuracy and precision（CV value）of the method were ranged from 83 to 92% and 2 to 8%, respectively. The extraction efficiency of spiked standard in sample were ranged from 68 to 93 %. Due to the immunotoxicological effect of organotin compounds on human, the analyzed data and uptake data of fish was used to estimate the noncarcinogenic risk of general population with hazard index.
The amount of organotin compounds such as butyltin ﹝ΣBTs：TBT, DBT, MBT﹞and phenyltins﹝ΣPhTs：TPhT, DPhT, MPhT﹞in fish from the northern（Bi-Sa）, central（Wu-chi）, eastern （Cheng-Kang） and southern（Shin-Da） Taiwan fishery markets varied with season and location. High values of ΣBTs（mainly TBT, 409.4±316.7 μg/kg, dry weight）at Shin-Da and low values of ΣPhTs（mainly TPhT, 293.7±115.4 μg/kg, dry weight）were found during winter （January 2002）at Cheng Kang, while high amount of ΣPhTs（mainly TPhT, 396.3±124.9 μg/kg, dry weight） at Bi-Sa and low ΣBTs（mainly TBT, 125.3±66.3 μg/kg, dry weight）were found during summer（August 2002）. The data shows that the concentrations of BTs in fish at summer were lower than at winter due to the higher degradtion of butyltins was happened by microorganism and UV light in summer. At the lower trophic levels, phenyltin concentrations were higher in benthic species（Pagrus major, yellowback sea-bream）, while butyltin concentrations were higher in inshore species（Scombermorous , Caesio caerulaurea）, this is may indicates that TBT is passed on primarily via the water, while TPhT is passed on to a larger extend via the sediment. To compare the offshore species and maricultured species revealed the higher contents of OTCs（ΣBTs＋ΣPhTs）in muscle of fish（offshore species, 1332.5 μg/kg, dry weight）and lower values in cultured fish（740.7 μg/kg, dry weight）might indicated that the organotion pollution problem in Taiwan is more serious in offshore coast compared with mariculture sites, where the fish live. Given these results, on the basis of calculated tolerable daily intake levels of tributyltin and triphenyltin are lower than the tolerable limits（0.1-0.2 μg/kg bw/day） and the hazard index（HI）are lower than 1. We concluded that the levels of organotin compounds in the marine products in fishery market of Taiwan were not sufficiently high to have any immunological toxic effect on human health.
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