Efficiency of tributyltin extraction from rhine river sediment

A Rhine river sediment sample was spiked with tributyltin (TBT), equilibrated for ten days and the tributyltin extraction efficiency was optimised using a simplex algorithm. Analysis was effected using hydride generation gas chromatography-atomic absorption spectroscopy (GC-AAS) apparatus. The results show that, in this sediment sample, different molarities of HCl in methanol extract different species with varying extraction efficiencies. The least polar extraction solution extracted TBT more efficiently, whilst DBT and MBT require molar solution of HCl in methanol for efficient extraction.     

Organotin concentrations in the Rivers Bure and Yare,Norfolk Broads,England

Butyltin concentrations have been measured at eight freshwater sites (rivers and lakes) in the Norfolk Broads, UK, during 1986 and 1987. Tributyltin (TBT) was found in water samples from seven of the sites. Wherever TBT was present, dibutyltin and (usually) monobutyltin occurred. Levels of TBT exceeded 100 ng dm^?3 in open stretches of both the Rivers Bure and Yare in 1986 and 1987. The highest concentration of TBT recorded for Wroxham Broad (a shallow lake) was 898 ng dm^?3. Values of up to 3.26 μg dm^?3 were measured in water samples taken from a marina. A depth profile for Wroxham Broad showed TBT to be uniformly distributed throughout the shallow water column. The results are discussed in relation to toxicity of TBT to freshwater organisms. Laboratory measurements of the degradation of TBT in freshwater from a marina gave a half-life of six days at 20°C in the light.     

Interference of tributyltin(IV)chloride on the vascular plant cells

In the recent past years, interest in the environmental impact of organotin(IV) compounds has risen markedly. Considering that most data in the scientific literature refers to the animal kingdom and not to higher plants cells, we tested the effects of organotin compounds on vascular plant cells, by studying the interaction of tributyltin chloride (TBTCl) with Allium cepa, Solanun tuberosum and Solanum melongena, vascular plants that are directly involved in the human food chain. The TBTCl effects on mitotic metaphase plates, on pollen grains and on both microtubers and adult tuber parenchymatic cells were investigated and the concentrations of TBTCl inside the treated parenchymatic cells were determined through ICP‐mass spectrometry. Oxygen and chlorophyll productions were also determined. The obtained results showed that TBTCl influenced not only morphology, but also the physiology of the vegetable cells since, despite the low concentrations used, the stress the cells were submitted to was experimentally confirmed. Moreover, the increase in the tin concentration in the cells, with increasing incubation time, showed that TBTCl possesses a very high capacity to be bioaccumulated and, as a consequence, it is able to enter the food chain. Copyright © 2006 John Wiley & Sons, Ltd.     

Imposex and organotin body burden in the dog‐whelk (Nucella lapillus L.) along the Portuguese coast

Nucella lapillus imposex—superimposition of male characters onto prosobranch (a subclass of gastropod molluscs) females—and organotin female body burden were surveyed on the Portuguese coast, from Vila Praia de Âncora (northern limit) to Praia da Luz (southern limit), at 17 sampling stations, between May and August 2003. The vas deferens sequence index (VDSI), the relative penis size index (RPSI), the percentage of females affected with imposex (%I) and the percentage of sterile females (%S) were used to assess the level of imposex at each site. VDSI, RPSI and %I were 0.20–4.04, 0.0–42.2% and 16.7–100.0%, respectively. Sterile females were found at stations 2 (6.2%), 5 (4.0%) and 7 (5.0%). Tributyltin (TBT) and dibutyltin (DBT) female body burdens were 23–138 and <10–62 ng Sn/g dry weight, respectively. TBT female body burden was significantly correlated with RPSI and VDSI [Spearman rank order linear correlation: RPSI vs TBT body burden (b.b.) r = 0.71, p < 0.01; VDSI vs logTBT body burden r = 0.71, p < 0.01]. Imposex and TBT b.b. were highest at sites located in the proximity of harbours, where TBT leaching from antifouling paints is more intense owing to the high concentration of ships and dockyard activities. Copyright © 2005 John Wiley & Sons, Ltd.     

Hepatic butyltin concentrations in beluga whales (Delphinapterus leucas) from the St Lawrence Estuary and northern Quebec,Canada

Butyltin (tributyltin TBT; dibutyltin DBT and monobutyltin MBT) speciation was measured in the liver of beluga whales from the St Lawrence Estuary and Hudson Strait (northern Quebec). Using GC–MS, liver samples were analysed from 21 beluga whales found dead, stranded along the shores of the St Lawrence during the period 1995–1998. In all cases, including a neonate specimen, the liver was contaminated with butyltin compounds with concentrations in the range 0.04–2.1 mg Sn kg⁻¹ on a dry weight basis. Liver samples of five beluga whales from Hudson Strait obtained in the summer of 1998 were also analysed. For these animals, hepatic butyltin concentrations were consistently below the detection limit (<0.5 ng Sn g⁻¹ for MBT and <0.2 ng Sn g⁻¹ for DBT and TBT). Compared with published data on the contamination by TBT of the marine mammals of the St Lawrence in 1988, these contemporary results clearly indicate that the level of contamination of the beluga whales in this coastal marine ecosystem has not decreased ten years after regulating the use of TBT‐based antifoulants on small craft. Copyright © 2000 John Wiley & Sons, Ltd.     

Studies of a mathematical model for temperature-modulated bioluminescence tomography

We introduce and study a mathematical model for temperature-modulated bioluminescence tomography (TBT). The model is capable of self-adjusting values of experimental parameters that are used in the formulation. Major theoretical results of this article include: Solution existence of the model, convergence of numerical solutions, an iterative scheme based on linearization, studies of the solution limiting behaviours when normalized total energy function and/or some or all the energy percentages in individual spectral bands are known exactly. Several numerical examples are included to illustrate the improvement of the accuracy of the reconstructed bioluminescent source distribution due to the employment of measurements from multiple temperature distributions.     

Biological activity studies on organotin(IV) complexes and parent compounds

This review summarized the literature and own data on the parent organotin(IV) compounds and complexes formed with biologically active ligands.     

Immunotoxicity of butyltins in tunicates

This study was designed to investigate the effects of butyltins on yeast phagocytosis in vitro by haemocytes of the colonial ascidian Botryllus schlosseri. This species has been reported to be very sensitive to organotins. Results show that, in analogy to reports on mammalian leukocyte re-activity, butyltins exert inhibitory effects on phagocytosis in a concentration-dependent manner, mainly by influencing cellular calcium homeostasis by interacting with the calcium pump. As the immunosuppressant activity of organotins described in mammals and teleosteans also occurs in an invertebrate marine species, the latter may assume a role as a sensitive biosensor of butyltins as immunotoxins in aqueous ecosystems.     

Spatial and seasonal behaviour of organotin compounds in protected subtropical estuarine ecosystems in Okinawa,Japan

The spatial and temporal behaviours of the organotin compounds (OTCs) (butyl- and phenyltin) were investigated in the Manko and Okukubi protected estuarine ecosystems on Okinawa Island, Japan from February to October 2006. Butyltin compounds (BTCs) were frequently detected in all seasons, while phenyltin (PhTs) were found in winter and early spring. In Manko estuary, the total mean concentrations of BTCs and PhTs were 22.78?±?30.85, (mean?±?SD, n?=?53) and 0.08?±?0.27?ng(Sn)?L^?1, respectively. In Okukubi estuary, BTCs and PhTs were 12.58?±?23.96 and 0.47?±?1.67 (n?=?55) ng(Sn)?L^?1, respectively. The Manko sediments can be classified as lightly contaminated, while the Okukubi sediments were uncontaminated with tributyltin (TBT). The mean levels of TBT shown in Manko estuary exceeded the threshold level and represent an ecotoxicological risk to sensitive aquatic life. Generally, the present study reports the occurrence and continuous input of OTCs in the protected estuaries, even 16 years after legal restriction of TBT usage in coastal waters was implemented by the Japanese Environmental Authorities.