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Tributyltin (TBT)

Tributyltin (TBT). Navdeep Brar Bio 564 Aquatic Tox. Usage and Production History. Organotins- itself highly toxic but when broken down to it’s derivatives, not as toxic. TBT is a Biocide Found in a variety of products:

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Tributyltin (TBT)

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  1. Tributyltin (TBT) Navdeep Brar Bio 564 Aquatic Tox

  2. Usage and Production History • Organotins- itself highly toxic but when broken down to it’s derivatives, not as toxic. • TBT is a Biocide • Found in a variety of products: • disinfectants, pesticides, fungicidal wood preservatives, textile disinfectants, and stabilizers in PVC resin. Paper and pulp mills, cooling towers, breweries, textile mills and leather-processing facilities • Primary use of TBT in antifouling boat paint –dating back to 1960s, in addition it was used in wood preservatives starting in 1958. • Banned in US but not worldwide

  3. Physical and Chemical Properties • TBT is insoluble in water and due it’s instable structure it binds to other compounds • eight compounds have been registered for use as marine antifoulants. • One of the most common TBT compounds is TBTO. This form is the most commonly present in TBT contaminate testing. • Remember the 3 butyl grps makes the TBTO very polar and hydrophobic Tributyltin TBTF Bis(tributyltin) oxide TBT MW:148.25 C12H28Sn

  4. Toxicity • Rats: oral LD50 of TBT is 1,500 mg/kg • Rabbits: oral LD50 of TBT 2,000 mg/kg • Mice: oral LD50 of TBT 900 mg/kg • Rats and Rabbits: dermal LD50 of TBTO is 11,700 mg/kg and 900 mg/kg http://pmep.cce.cornell.edu/profiles/extoxnet/pyrethrins-ziram/tributyltin-ext.html http://www.epa.gov/waterscience/cs/biotesting/Chem-6.pdf • Gastropods (Ostrea edulis): 96LC50 of TBTO is 3000µg/L • Mummichogs (Fundulus heteroclitus) and sheepshead minnow(Cyprinodon variegatus): 96LC50 TBT= 23.8 and 25.9 µg/L Bushong, S.J., et al. (1988)

  5. Mode of Entry Into The Aquatic Environment • Waste waster • Urban runoff • Antifouling paint www.greenpeace.org

  6. Mode of Entry in Aquatic Organisms • Readily absorbed through gills of organisms in the sediment and water column. • In small mammals dermal absorption or through ingestion.

  7. Endocrine Disruption Capabilities in Gastropods • Physiological changes: Balling or deformations of the shell • Reproductive alterations: Imposex • Female penis-like formation and spermatogensis • Sterility in females • Hormonal imbalance • 1,25,(OH)2→ Vitamin D3 • P450 Aromatase inhibitor→ Excess DHT (potent androgen)

  8. Endocrine Disruption Cont.. • There is more to the imposex story…Recent studies on (Hexaplex trunculus) show interactive effects of other contaminates to TBT. In addition potential alterations in the stress axis, leading to high rates of imposex in gastropods

  9. TBT effects on fish • Few studies conducted on TBT effects on fish • Masculinizingeffects on undifferentiated embryos • Interference in female reproductive development • Recent study conducted on (Sebastiscus marmoratus), when exposed to 0,1,10,100 ng/L of TBT • Suppression of ovarian development at all concentrations • Decrease in mature follicles • High rates of atresia (cell death) • Dose-dependent reduction of estradiol • Elevated ratios of T/E2

  10. Mode of Cellular Action • TBT is a persistent endocrine disruptor • Primary effects of TBT are masculization of females. • P450 Aromatase enzyme inhibitor: build up of Androstenedione and Testosterone. • Recently it has been suggested that TBT inactivates CYP expression genes leading to the loss of catalytic function and destruction of native enzyme. • In addition, CYP1A1 and GST mRNA expression showed a TBT concentration-dependent decrease • Little is known about potential TBT effects on CYP enzymatic expression and other possible genetic and development effects.

  11. O.edulis where are they now? • In some parts of the UK O.edulis are making a comeback since the 1987 ban. • Young adults of native O. edulis have showed an increasing trend in number since 1992.

  12. It’s not over yet… • In a 2008 study, waste water from two Norwegian cities was tested for contamination • Found significant TBT in runoff particles indicating urban runoff such as long-lasting house paints and PVC stabilizer. • Replenishment of TBT: top layer of harbor sediment TBT levels did not decrease whereas PAHs and PCBs have shown decreased concentrations • TBT was higher than the Norwegian Tolerable Risk (NTR) in sediment samples, settling and runoff particles.

  13. Bibliography Bushong, SJ., Lenwood WH., Hall SW., Johnson EW., & Herman, RL. (1998) Acute Toxicity of Tributyltin to Selected Chesapeake Bay Fish and Invertebrates. Water Research 22 (8) 1027-1032. Choi, M., Choi, H-G., Moon H-B., & Kim G-Y. (2008). Spatial and Temporal Distribution of Tributyltin (TBT) in Seawater, Sediments and Bivalves from Coastal Areas in Korea. Environ Monit Assess 8-27. Cornelissen, G., Pettersen, A., Nesse, E., Eek, E., Helland, A., & Breedveld, GD. (2008). The contribution of Urban runoff to Organic Contaminant Levels in Harbour Sediment Near Two Norwegian Cities. Marine Pollution Bulletin56 565-573. Dahllof, I., Agrenius, S., Blanck, H., Hall, P., Magnusson, K., & Molander, S. (2001). The Effect of TBT on the Structure of a Marine Sediment Community-A Boxcosm Study. Marine Pollution Bulletin42 (8). 689-695. Devier, M-H., Augagneru, S., Budzinski, H., Menach, KL., Mora, P., Narbonne, J-F., & Garrigues, P. (2004) One-year monitoring survey of organic compounds (PAHs, PCBs, TBT) heavy metals and biomarkers in blue mussels from the Aracachon Bay, France. The Royal Society of Chemistry7 224-240. Dimitriou, P., Castritsi-Catharios, J., & Miliou, H. (2003). Acute Toxicity Effects of Tributyltin Chloride and Triphenyltin Chloride on Gilthead Seabream, (Sparus aurata) embryos.Ecotoxicology and Environmental Safety 54 (1) 30-35. Garaventa, F., Centanni, E., Fiorini, S., Noventa, S., Terlizzi, A., Faimali, M., & Pavoni, B. (2008). New Implications in the use of Imposex as a Suitable Tool for Tributyltin contamination: Experimental Induction in Hexaplex trunculus (Gastropoda, Muricidae) with Different Stressor. Cell Biol Toxicol. Mortensen, AS., & Arukwe, A. (2007). Modulation of Xenobiotic Biotransformation System and Hormonal Responses in Atlantic Salmon (Salmo salar) After Exposure to Tributyltin (TBT). Comparative Biochemistry and Physiology145 431-441. Rees, HL., Waldock, R., Matthiessen, P., & Pendle, MA. (2000). Improvements in the Epifauna of the Crouch Estuary (United Kingdom) Following a Decline in TBT Concentrations. Marine Pollution Bulletin42(2) 137-144. Vogt, C., Nowak, C., Diogo, JB., Oetken, M., Schwenk, k., & Oehlmann, J. (2007). Multi-generation Studies with Chironomus riparius-Effects of Low Tributyltin Concentrations on Life History Parameters and Genetic Diversity. Chemosphere67 2192-2200. WEBSITES https://www.epa.gov/waterscience/criteria/tributyltin/fs-final.htm http://pmep.cce.cornell.edu/profiles/extoxnet/pyrethrins-ziram/tributyltin-ext.html http://www.epa.gov/waterscience/cs/biotesting/Chem-6.pdf

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