Tributyltin biomonitoring using prosobranchs as sentinel organisms

Tributyltin (TBT) compounds, some of the most toxic xenobiotics, produce a variety of pathological reactions in animals. A reliable biomonitoring method to assess the degree of environmental TBT pollution has been described based on investigations of virilization phenomena in prosobranch snails (Mollusca: Gastropoda). Examples are the imposex phenomenon in marine and freshwater species, the intersex reaction in littorinids and the reduction of female sexual glands and offspring numbers in further species resulting mainly in a sterilization of females. The degree of imposex or intersex in populations is determined by different biomonitoring indices which allow to assess the TBT pollution of the environment at low costs with high precision. The effectiveness of TBT legislations is analysed by extensive surveys in France and Ireland indicating that there is still a continuing threat to sensitive marine organisms. TBT disturbs the biosynthesis of steroid hormones on the level of estrogen biosynthesis. The observed virilization phenomena seem due to an inhibition of the cytochrome P-450 dependent aromatase by this organotin compound.     

Imposex in Sea Snails,Caused by Organotin (Tributyltin and Triphenyltin) Pollution in Japan: a Survey

A country-wide survey and laboratory experiments on imposex (a superimposition of male sex organs on female sea snails) in Japanese sea snails were carried out: 38 species were observed to be affected by imposex. For the rock shell, Thais clavigera , the percentage occurrence of imposex was 100% at almost all sites surveyed. The degree of imposex seemed to be positively correlated with the concentrations of tributyltin (TBT) and triphenyltin (TPT) in the species. The results of laboratory experiments showed that imposex in T. clavigera was initiated and promoted by both TBT and TPT. Many oviduct-blocked individuals, which were thought to be sterile, were observed in T. clavigera at sites near marinas and harbours. The effects of organotin pollution on the population of T. clavigera were observed at the sites near marinas. From the results of the additional country-wide survey on imposex in T. clavigera during 1993–1995, serious organotin pollution and imposex symptoms in the species are still continuing in Japan. © 1997 by John Wiley & Sons, Ltd.     

Imposex and organotin contamination in Nassarius reticulatus (L.) along the Portuguese coast

Nassarius reticulatus (whelk) imposex levels and organotin body burden (b.b.) were surveyed along the Portuguese coast, from Vila Praia de Âncora (northern limit) to Lagos (southern limit), between May and August 2003. The percentage of females affected with imposex (%I), the relative penis length index (RPLI), the vas deferens sequence index (VDSI) and the degree of female oviduct convolution index (AOS) were used to assess the level of imposex at each site. These imposex indices were determined for 23 sampling stations throughout the coast and were in the range 0.0–100%, 0.0–90%, 0.0–5.0 and 0.0–1.3 respectively. Sterile females (i.e. females carrying aborted egg capsules inside the capsule gland) were found inside the harbours of Viana do Castelo (8.5%) and Aveiro (3.7%). Organotin compounds were assessed at 10 sampling sites spread along the coast. Tributyltin (TBT) b.b. in females varied between 39 and 1679 ng g^?1 (as tin) dry weight, and dibutyltin (DBT) and monobutyltin (MBT) varied in the ranges 23–1084 ng g^?1 (as tin) d and 18–939 ng g^?1 dry wt respectively. Among the butyltins, the major fraction corresponded to TBT (47.4%), followed by DBT (27.6%) and MBT (25.0%), which indicates recent TBT inputs. Triphenyltin (TPT) levels ranged from <5 to 21 ng g^?1 (as tin), and, when quantifiable, represented on average 10% of that of TBT. TPT was the dominant phenyltin and was detected in 60% of the sampling stations. The imposex was significantly correlated to ln (TBT) (Spearman r = 0.918, p < 0.001 for RPLI; r = 0.864, p < 0.001 for VDSI; r = 0.828, p < 0.01 for AOS). The higher levels of imposex and TBT contamination occurred inside or close to harbours, which we identified as ‘hotspots’ of pollution along the coast. Comparing the results obtained in the current work with those reported in a similar survey in 2000, imposex and TBT b.b. varied locally but did not reveal any global trend in the variation of TBT pollution along the Portuguese coast over the 3 year period. Copyright © 2005 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.     

Adsorption characteristics of tributyltin on municipal solid waste compost

The sorption behaviour of tributyltin (TBT) from reconstituted seawater onto municipal solid waste (MSW) compost was investigated to give first insights into the equilibrium and kinetic behaviour of this process. The rate of adsorption, the influence of pH, and the adsorbate hydrophobicity on the partitioning process were investigated. Adsorption kinetics indicated an initial fast rate of adsorption of TBT followed by a slower rate. The similarity of Freundlich sorption and desorption coefficients for TBT showed that the sorption process is also reversible, similar to that for the adsorption of TBT onto marine sediments. It was found that the adsorption capacity for TBT onto compost was highest at pH 6.7, and for other organotins it increased with increasing adsorbate hydrophobicity, following the trend tripropyltin < TBT < tripentyltin. The use of washed MSW compost as a sorbent for the purification of TBT‐contaminated wash waters as generated in large quantities during hull cleaning in dry docks is suggested as a mitigatory measure against pollution of the marine environment by TBT. Calculations suggest that modest amounts of compost will likely be required to treat the contaminated wastewaters generated from the Malta dry docks if a multiple batch system is adopted. Copyright © 2005 John Wiley & Sons, Ltd.     

Bioaccumulation of Butyltin Compounds in Marine Mammals: The Specific Tissue Distribution and Composition

Although organotins are notorious man-made organometallic species introduced into the aquatic environment, no investigation had been concerned with contamination of higher trophic animals such as marine mammals until the last few years. Our recent work demonstrated the detection of butyltin compounds (BTCs), including mono- (MBT), di-(DBT), and tri-butyltin (TBT) in marine mammals. This paper reviews BTC contamination in higher trophic animals, based on our recent publications. Analysis for BTCs showed significant accumulation in tissues and organs of three finless porpoises ( Neophocaena phocaenoides ) collected from Japanese coastal waters. More than 10 μg of butyltin ions per gram on a wet weight basis were detected in the liver of a porpoise collected in the semi-closed sea. Distribution of BTCs in the tissues and organs of the porpoises showed a similar pattern to several other marine mammal species: higher concentrations in liver and kidney, and lower in muscle and blubber. In addition, tissues and organs from two water birds and one sea turtle species were also analyzed for BTCs, and their concentrations and compositions were compared among the species. The results showed that the distribution of these contaminants extends widely, not only to marine mammals but also to other higher trophic species. On the other hand, the composition of the BTCs exhibited a specific profile in each species. The ratios of hepatic concentrations of DBT or MBT to TBT for marine mammals were relatively lower than those of water birds and the sea turtle, indicating that metabolism and excretion of TBT may be less efficient in the mammalian species. © 1997 by John Wiley & Sons, Ltd.     

Organotin contamination,imposex and androgen/oestrogen ratios in natural populations of Nassarius reticulatus along a ship density gradient

Levels of organotin body burden (expressed as tin), imposex and steroid hormones (testosterone, 17β‐oestradiol, testosterone glucuronide and sulfate conjugates) were investigated in natural populations of Nassarius reticulatus in the Ria de Aveiro (northwest Portugal) between 1997 and 1999. The tributyltin (TBT) whole body burden (b.b.) of females presented increasing gradients from the adjacent open coast (16–26 ng g^?1 dry weight (d.w.)) towards the ports inside the Ria de Aveiro (195–272 ng g^?1 d.w.). Triphenyltin b.b. was only detected at the most polluted port (22 ng g^?1 d.w.). Imposex also presented increasing values from the adjacent coast (vas deferens sequence index (VDSI): 0.0–0.5; relative penis length index (RPLI): 0.0–2.4; penis length index (PLI): 0.0–0.3 mm; percentage of affected females (%I): 0–30) towards the ports (VDSI: 3.8–4.8; RPLI: 51–80; PLI: 6.7–10.8 mm; %I: 100). The testosterone levels in females without imposex were always lower than in females with imposex, and the ratio of testosterone/17β‐oestradiol in females tended to increase with increasing imposex and organotin contamination. In spite of the large difference in the female testosterone and 17β‐oestradiol levels between summer and winter, related to the reproductive cycle, the spatial trend of the testosterone/17β‐oestradiol ratio was remarkably similar in shape and values in the two seasons. Imposex was significantly correlated with the TBT b.b. and the testosterone/17β‐oestradiol ratio in females. The testosterone conjugate levels did not show any clear pattern with the increasing values of imposex and TBT contamination. Copyright © 2005 John Wiley & Sons, Ltd.     

Search for triorganotins along the Mar del Plata (Argentina) marine coast: finding of tributyltin in egg capsules of a snail Adelomelon brasiliana (Lamarck, 1822) population showing imposex effects

Cases of imposex were clearly identified in Adelomelon brasiliana living in the Mar del Plata (Argentina) coastal area; percentages as high as 50.0% were determined among the samples studied. These were the first reported cases of ocurrence of imposex in this type of gastropod. Since this is one of the known tributyltin (TBTs) effects, and no previous reports of determination of TBTs in gastropods eggs were found, methods were developed for the speciation and quantitative determination of organotins in A. brasiliana egg capsules. Determination of organotins in samples collected in the Mar del Plata area showed contents of tributyltin chloride (TBT) as high as 400 ng l^?1 in water and 6.50 µg g^?1 in sediments of areas of intensive boat traffic. The results showed the presence of TBT in the egg capsules of A. brasiliana at three different instars (range 0.264–1.86 µg per egg). As far as we know, this is the first report of the finding of TBT in gastropod egg capsules. Copyright © 2004 John Wiley & Sons, Ltd.     

Isotope dilution analysis mass spectrometry for the routine measurement of butyltin compounds in marine environmental and biological samples

The highly qualified primary method of species-specific isotope dilution analysis has been employed in this work to evaluate for the first time the levels of butyltin compounds in the estuary of the river Eo (Northwest Spain) where there is, since many years, a high oyster farming activity. A spike solution containing mono-, di- and tributyltin enriched in ¹¹⁹Sn allowed the simultaneous determination of the three compounds in different marine environmental and biological samples collected in this area (seawater samples, sediments and biological tissues of four different marine species). The results obtained in this work showed toxic TBT levels for many marine species in 45% of the seawater samples analyzed whereas significant organotin concentrations were found to be obtained only in one of the sediments analyzed. On the other hand, TBT levels ranging from 20 to almost 200 ng g^− 1 (dry weight) were obtained in the different biological tissues analyzed demonstrating the bioaccumulation of organotin compounds in certain marine species.     

Determination of 1-Hydroxy Pyrene in Fish Bile by Synchronous Fluorescence Spectrometry

Environmental pollution with polynuclear aromatic hydrocarbons (PAHs) has being concerned. PAHs are mainly bound to sediment particles in the aquatic environment, but may still be biologically available to marine organisms^[1]. So PAHs could be harmful to human beings by food chain transportation and accumulation. Routine monitoring of PAHs levels in the aquatic environment usually involves the determination of parent PAHs in sediment samples. Additional information on the actual uptake of these compounds by aquatic organisms can be obtained by a biomonitoring approach. However, the biotransformation rates of PAHs in fish are relatively high, and the analysis of parent PAHs in liver and muscle tissue is difficulty. Therefore, the biomonitoring of PAHs uptake should be concerned on the determination of PAHs metabolites in excreta. In this study, a simple, fast and easy operation synchronous fluorimetry has been established for this purpose.     

Tributyltin determination in marine sediments: A comparative study of methods

Two independent speciation methods have been applied to the determination of tributyltin (TBT) in marine sediments: (1) acetic acid leaching/hydride generation/cold trapping/GC/quartz furnace AA; and (2) toluene–tropolone extraction/HPLC/GFAA. TBT determines in a typically moderately polluted sediment (Porto Vecchio Bay, Corsica, France) are in very good agreement, as also are the determination of total recoverable tin by the first method and by a direct one using strong acid leaching followed by GFAA. These cross-verifications lead one to conclude that both speciation methods are convenient and allow for valid determination of TBT in marine sediments, with no loss of TBT. Method-induced modification of tin speciation has not been observed.     

The Application of Active Biomonitoring with the Use of Mosses to Identify Polycyclic Aromatic Hydrocarbons in an Atmospheric Aerosol

The use of biological indicators of environmental quality is an alternative method of monitoring ecosystem pollution. Various groups of contaminants, including organic ones, can be measured in environmental samples. Polycyclic aromatic hydrocarbons (PAHs) have not yet been determined by the moss bag technique. This technique uses several moss species simultaneously in urban areas to select the best biomonitoring of these compounds, which are dangerous to humans and the environment. In this research, a gas chromatography coupled with mass spectrometry was used for the determination of selected PAHs in three species of mosses: Pleurozium schreberi, Sphagnum fallax and Dicranum polysetum (active biomonitoring) and for comparison using an air filter reference method for atmospheric aerosol monitoring. The chlorophyll fluorescence of photosystem II (PSII) was also measured to assess changes in moss viability during the study. As a result of the study, the selective accumulation of selected PAHs by mosses was found, with Pleurozium schreberi being the best bioindicator—9 out of 13 PAHs compounds were determined in this species. The photosynthetic yield of photosystem (II) decreased by 81% during the exposure time. The relationship between PAHs concentrations in mosses and the total suspended particles (TSP) on the filter indicated the possibility of using this bioindicator to trace PAHs in urban areas and to apply the moss bag technique as a method supporting classical instrumental air monitoring.     

Research on tributyltin in Australian estuaries

Tributyltin (TBT) from marine antifouling paints has been shown to have a major impact on the oyster industry in eastern Australia. Current research projects are examining the impact of TBT on Australian estuaries, assessing the response of sensitive biota to recently imposed bans and determining whether a continuing use of TBT on large vessels is an environmental concern.     

Speciation of butyltin compounds in marine sediments with headspace solid phase microextraction and gas chromatography – mass spectrometry

A method for the determination of organotin compounds (monobutyl = MBT, dibutyl = DBT, and tributyltin = TBT) in marine sediments by headspace Solid Phase Microextraction (SPME) has been developed. The analytical procedure involved 1) extraction of TBT, DBT and MBT from sediments with HCl and methanol mixture, 2) in situ derivatization with sodium tetraethylborate and 3) headspace SPME extraction using a fiber coated with poly(dimethylsiloxane). The derivatized organotin compounds were desorbed into the splitless injector and simultaneously analyzed by gas chromatography – mass spectrometry. The analytical method was optimized with respect to derivatization reaction and extraction conditions. The detection limits obtained for MBT, DBT and TBT ranged from 730 to 969 pg/g as Sn dry weight. Linear calibration curves were obtained for all analytes in the range of 30–1000 ng/L as Sn. Analysis of a standard reference sediment (CRM 462) demonstrates the suitability of this method for the determination of butyltin compounds in marine sediments. The application to the determination of TBT, DBT and MBT in a coastal marine sediment is shown.     

同步荧光法检测鱼胆汁中的1-羟基芘

建立了和同步荧光法测定鱼胆汁的1－羟基芘（1－HP）的方法。该方法通过直接测定鱼胆汁的多环芳烃（PAHs)的代谢产物之一1－HP，用于判断PAHs生物有效部分对海岸养殖水环境的污染程度。以真鲷（Pargrosomus major，简称Pm），Mian鱼（Niba miichthys，简称Nm）为实验对象，现场实验结果令人满意。     

Speciation of butyltin compounds in marine sediments with headspace solid phase microextraction and gas chromatography mass spectrometry

A method for the determination of organotin compounds (monobutyl = MBT, dibutyl = DBT, and tributyltin = TBT) in marine sediments by headspace Solid Phase Microextraction (SPME) has been developed. The analytical procedure involved 1) extraction of TBT, DBT and MBT from sediments with HCl and methanol mixture, 2) in situ derivatization with sodium tetraethylborate and 3) headspace SPME extraction using a fiber coated with poly(dimethylsiloxane). The derivatized organotin compounds were desorbed into the splitless injector and simultaneously analyzed by gas chromatography - mass spectrometry. The analytical method was optimized with respect to derivatization reaction and extraction conditions. The detection limits obtained for MBT, DBT and TBT ranged from 730 to 969 pg/g as Sn dry weight. Linear calibration curves were obtained for all analytes in the range of 30-1000 ng/L as Sn. Analysis of a standard reference sediment (CRM 462) demonstrates the suitability of this method for the determination of butyltin compounds in marine sediments. The application to the determination of TBT, DBT and MBT in a coastal marine sediment is shown.     

Effects of γ-sterilization on butyltin homogeneity and content in sediments: a GC–ICP–MS study

A GC-ICP-MS method based on extraction and alkylation of butyltins with sodium tetraethylborate was used to quantitatively assess the fate of these analytes in solutions and sediments following exposure to gamma-irradiation. The effects of a 2.5 Mrad sterilization dose on three butyltin species in both methanolic calibration solutions and in sediment matrices were investigated. Although significant losses of tributyltin (TBT, 90%), dibutyltin (DBT, 100%) and monobutyltin (MBT, 80%) were detected in standard solutions prepared in methanol following gamma-irradiation, no species inter-conversion occurred. Some degradation of TBT (38%) and DBT (32%) but no significant change in MBT content was found using a spiked sediment CRM HISS-1. Conversion DBT to MBT in spiked HISS-1 was deduced. Much smaller degradation of TBT (16% loss) and 10% loss of DBT by conversion to MBT (14% gain) was registered using a sediment blend of PACS-2 and HISS-1 (SOPH). Despite some initial losses of TBT and DBT due to irradiation, better than 2% RSD in both TBT and DBT concentrations measured in twelve different bottles of blended sediment SOPH were obtained, indicating the material may be considered homogeneous for these analytes. Results from a long-term five-year stability study of PACS-2 show that all three butyltins are stable during storage at 4 degrees C followed with 2.5 Mrad minimum dose of gamma-irradiation sterilization treatment.     

Sorption of tributyltin in seawater by municipal solid waste compost

The use of municipal solid waste (MSW) compost as a sorbent for tributyltin (TBT) in seawater was investigated. TBT‐contaminated seawater, both artificially prepared and that collected from Msida Creek yacht marina (Malta), was allowed to percolate through untreated and water‐washed columns of compost and then analysed for organotins using gas chromatography‐flame photometric detection. About 90% of dissolved TBT ranging in concentration from about 800 to 8000 ng_Snl^?1 was sorbed by treating 500 ml solutions with 100 g untreated compost. On the other hand, no detectable breakthrough of TBT was observed from compost that had previously been washed by water to remove soluble organic matter. Breakthrough of TBT from unwashed compost is thought to be due to formation of complexes between the soluble organic matter in compost and aquated TBT, which renders the organotin more hydrophilic. The use of washed MSW compost as sorbent for the purification of TBT‐contaminated waters generated in large quantity during hull‐cleaning activities in drydocks is suggested as a mitigatory measure against the impact of TBT on the coastal marine environment. Copyright © 2001 John Wiley & Sons, Ltd.     

Review: Biodegradation of tributyltins (organotins) by marine bacteria

Many marine bacterial strains have an inherent capability to degrade toxic organotin compounds, especially tributyltins (TBTs), that enter into the environment in the form of insecticides, fungicides and antifouling paints as a result of anthropogenic and industrial activities. Significant degradation of these compounds in the ambient environment may take several years, and it is necessary to consider methods or strategies that can accelerate the degradation process. There have been few demonstrations of biological degradation of these organotin biocides exclusively in laboratory‐scale experiments. Compared with the few bench‐scale degradation processes, there are no reports of field‐scale processes for TBT bioremediation, in spite of its serious environmental threat to non‐target organisms in the aquatic environment. Implementation of field‐scale biodegradation of TBT requires inputs from biology, hydrology, geology, chemistry and civil engineering. A framework is emerging that can be adapted to develop new processes for bioremediation of toxic environmental wastes. In the case of TBT bioremediation, this framework incorporates screening and identification of natural bacterial strains, determination of optimal conditions for growth of isolates and TBT degradation, establishment of new metabolic pathways involved in TBT degradation, identification, localization and cloning of genes involved in degradation and in TBT resistance, development of suitable microbial strains using genetic manipulation techniques for practical applications and optimization of practical engineering processes for bioremediation of organotin‐contaminated sites. The present review mainly addresses the aspect of TBT biodegradation with special reference to environmental sources of TBT, chemical structure and biological activity, resistant and degrading bacterial strains, possible mechanisms of resistance and degradation and the genetic and biochemical basis of TBT degradation and resistance. It also evaluates the feasibility and potential of natural and genetically modified TBT‐degrading bacterial strains in field‐scale experiments to bioremediate TBT‐contaminated marine sites, and makes recommendations for more intensive and focused research in the area of TBT bioremediation mediated by marine bacterial strains. Copyright © 2002 John Wiley & Sons, Ltd.     

Contamination by butyltin compounds in harbour porpoise (Phocoena phocoena) from the Black Sea

Concentrations of butyltin compounds (BTs) were determined in harbour porpoise (Phocoena phocoena) collected from the Turkish coastal waters of the Black Sea. Total butyltin compounds (∑ BTs) in the liver were in the range of 89–219 ng/g on a wet weight basis. The dibutyltin (DBT) residues were higher than those of tributyltin (TBT), suggesting the degradation of TBT to DBT in the liver and the metabolic capacity comparable to other marine mammals. Any sex difference and age-dependent accumulation of BTs residues were not found in harbour porpoises, but residue levels increased until maturity and then remained constant. When compared with other marine mammals, the present results indicate that the Black Sea is also contaminated with butyltin compounds, but to a lesser degree than coastal waters of developed nations. The biomagnification factor in harbour porpoises was 0.8, which was comparable with pinnipeds and lower than cetaceans. Received: 23 December 1996 / Revised: 15 April 1997 / Accepted: 16 April 1997