Dissolved butyltins in marine waters of the netherlands three years after the ban

In 1990 the Dutch government banned the use of tributyltin-containing antifouling paint for ships up to 25m long. Concentrations of dissolved (<0.45 μm) tributyltin and its degradation products di- and mono-butyltin were determined in six selected marinas during three consecutive years with a frequency of five times a year, starting in 1990. The highest butyltin concentrations were found in Scharendijke located in the salt water lake Grevelingen: up to 2500 ng dm^?3. In tidal-water marinas butyltin concentrations were in the order of 50–300 ng dm^?3, depending on the boating and dredging activity. In some marinas higher butyltin concentrations were found during the summer period, probably indicating the illegal use of tributyltin-containing antifouling paints. No clear trend of decrease in dissolved tributyltin concentrations in the different marinas has been found. Due to the equilibrium between the butyltins dissolved in the water and the butyltins adsorbed onto the sediment, water concentrations will remain more or less constant.     

Alternative antifouling biocides

In response to increasing scientific evidence on the toxicity and occurrence of organotin residues from antifouling paints in the aquatic environment, the use of triorganotin antifouling products was banned on boats of less than 25 m length in many countries during 1987. The use of tributyltin (TBT) products on small boats was superseded by products based on copper, containing organic booster biocides to improve the efficacy of the formulation. Available information and evidence on the occurrence, fate and toxicity of these biocides is reviewed. It is concluded that increased copper concentrations in the aquatic environment, due to the increased use of copper‐based antifoulants, do not have significant effects on marine ecosystems. However, lack of validated analytical methods, limited monitoring data, and very little information about the fate and toxicity of the booster biocides in the aquatic environment, make accurate risk assessments in relation to these compounds difficult. Copyright © 1999 John Wiley & Sons, Ltd.     

Occurrence and chemical speciation analysis of organotin compounds in the environment: A review

Environmental concerns regarding organotin compounds have increased remarkably in the past 20 years, due in large part to the use of these compounds as active components in antifouling paints [mainly tributyltin (TBT)] and pesticide formulations [mainly triphenyltin (TPhT)]. Their direct introduction into the environment, their bio-accumulation and the high toxicity of these compounds towards “non-target” organisms (for example: oysters and mussels) causes environmental and economic damage around the world. As a consequence, the presence and absence of organotin compounds is currently monitored in a range of environmental matrices (e.g., water, sediment and shellfish) to examine the utility of controls meant to regulate the level of contamination as required in some EC Directives and the Water Framework Directive 2000/60/EC. To evaluate the environmental distribution and fate of these compounds and to determine the effectives of legal provisions adopted by a number of countries, a variety of analytical methods have been developed for organotin determination in the environment. Most of these methods include different steps such as extraction, derivatisation and clean up. The aim of the present review is to evaluate the environmental distribution, fate and chemical speciation of organotin compounds in the environment.     

Contamination and biomethylation of organotin compounds in pearl/fish culture areas in Japan.

Uwakai of Japan is famous for pearl and yellowtail fish culture. Recently, pearl culture farming in that region has suffered from a low production of pearls. An illegal use of organotin antifouling paints on fishing nets was reported. In the line of pollution studies, thus, the present investigation was carried out to examine the contamination status and fate of organotin compounds. Totally, 23 water, 10 sediment and 8 pearl oyster tissue samples were analyzed for tributyltin (TBT), triphenyltin (TPT), and their breakdown products (di- and mono compounds) by gas chromatography combined with inductively coupled plasma mass spectrometry (GC/ICP-MS). The results show that the TBT concentrations in water, sediment and biota were in the range from 0.11 to 10.6 ng Sn l(-1), 0.35 to 2500 ng Sn g(-1), and 50.4 to 181 ng Sn g(-1), respectively. The values for sediment and biota are expressed on the dry-weight basis. Triphenyltin in water, sediment and biota were in the range from 0.009 to 0.108 ng l(-1), non-detect to 12.7 ng g(-1), and non-detect to 6.83 ng g(-1), respectively. Although the TBT concentration in seawater is below the tentative assessment level of 10 ng l(-1) set by the Japanese Environment Agency in 1992, it may cause endocrine disruption/other effects in aquatic organisms. Octyltin compounds (mono-, di- and trioctyltin) were also quantified in seawater and sediment. The detection of dibutyldimethyltin (DBDMT) and tributylmonomethyltin (TBMMT) in sediment (methylated butyltins comprised 2.8-31% of total butyltins), and TBMMT in seawater suggested that biomethylation of anthropogenic tributyltins is a significant transformation pathway in the coastal environment.     

Analytical methods for the determination of common booster biocides in marine samples

Booster biocides are organic compounds that are added to antifouling copper-based paints to improve their efficacy. Due to their widespread use, they are common pollutants of marine ecosystems. Some of these compounds show acute and chronic toxic effects in non-targeted organisms at concentrations as low as ng L⁻¹. The determination of these compounds is therefore important, and for some, which are prioritized in the EU water framework directive, a necessity.     

Simultaneous butyltin determinations in the microlayer,water column and sediment of a northern Chesapeake Bay marina and receiving system

Butyltins were determined in the microlayer, water column and sediment of a northern Chesapeake Bay marina and its receiving system. Concentrations of the toxicant species tributyltin (TBT) ranged from 60 to 4130 ng dm⁻³ in the microlayer, from 34 to 367 ng dm⁻³ in the water column and from <0.05 to 1.4 m̈g g⁻¹ (dry weight) in sediment. TBT concentrations in all three environmental compartments were higher in the marinas than in the receiving system. Concentrations of TBT in the microlayer and water column of the study area were potentially toxic to sensitive aquatic biota. The microlayer appears to be depleted in dibutyltin relative to tributyltin compared to both water column and sediment.     

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.     

Determination of diuron and the antifouling paint biocide irgarol 1051 in Dutch marinas and coastal waters

A sensitive LC–electrospray MS–MS method using off-line solid-phase extraction for the determination of diuron and Irgarol 1051 has been developed, enabling determination of both compounds at sub-ppt levels. Diuron and Irgarol 1051 are used as alternatives for tributyltin in antifouling paints that prevent growth on boats, and an increase in their application is anticipated because of the upcoming ban on tributyltin in 2003. In 2000, a survey was carried out to assess contamination with diuron and Irgarol 1051 of a number of Dutch marinas and coastal waters. Depending on the time of year, both compounds were encountered at levels higher than the maximum permissible concentrations of 430 and 24 ng/l for diuron and Irgarol 1051, respectively. Outside marinas at reference locations, concentrations were much lower, depending on the geographical situation and the nature of the water exchange with the environment related to tidal cycles. A seasonal influence was observed with highest levels in summer, corresponding to the yachting season for both compounds. For diuron, use in agriculture could have contributed to the high concentration encountered in surface waters.     

Organometallics in the nearshore marine environment of Australia

This review draws together published information on the occurrence and biogeochemical cycling of selenium, arsenic and tin in the nearshore marine environment of Australia. The selenium content of marine organisms is well documented but little information is available on the selenium content of waters and sediments. The speciation of selenium in organisms, water and sediments is unknown although it appears that selenium is associated with proteins. The occurrence and speciation of arsenic in marine organisms has been extensively studied, with arsonobetaine being isolated as the probable end-product of arsenic metabolism in marine food chains. However, organisms can produce other organoarsenic compounds, e.g. trimethylarsine oxide, which may be metabolized to toxic end-products. Little is known about the occurrence and speciation of arsenic in waters and sediments. Arsenic(V) is dominant in oxygenated waters, with appreciable quantities of arsenic(III) in some deoxygenated waters. There are few data for tin in water, sediments or organisms and no data on naturally occurring tin species. Tributyltin has been measured in water, sediment and organisms from areas affected by boating activity.     

Structures and antifouling properties of low surface energy non-toxic antifouling coatings modified by nano-SiO_2 powder

Antifouling coatings are used to improve the speed and energy efficiency of ships by preventing or- ganisms, such as barnacles and weed, building up on the underwater hull and helping the ships movement through the water. Typically, marine coatings are tributyltin self-polishing copolymer paints containing toxic molecules called biocides. They have been the most successful in combating bio- fouling on ships, but their widespread use has caused severe pollution in the marine ecosystem. The low surface energy marine coating is an entirely non-toxic alternative, which reduces the adhesion strength of marine organisms, facilitating their hydrodynamic removal at high speeds. In this paper, the novel low surface energy non-toxic marine antifouling coatings were prepared with modified acrylic resin, nano-SiO2, and other pigments. The effects of nano-SiO2 on the surface structure and elastic modulus of coating films have been studied, and the seawater test has been carried out in the Dalian Bay. The results showed that micro-nano layered structures on the coating films and the lowest surface energy and elastic modulus could be obtained when an appropriate mass ratio of resin, nano-SiO2, and other pigments in coatings approached. The seawater exposure test has shown that the lower the sur- face energy and elastic modulus of coatings are, the less the marine biofouling adheres on the coating films.     

Structures and antifouling properties of low surface energy non-toxic antifouling coatings modified by nano-SiO<Subscript>2</Subscript> powder

Antifouling coatings are used to improve the speed and energy efficiency of ships by preventing organisms, such as barnacles and weed, building up on the underwater hull and helping the ships movement through the water. Typically, marine coatings are tributyltin self-polishing copolymer paints containing toxic molecules called biocides. They have been the most successful in combating biofouling on ships, but their widespread use has caused severe pollution in the marine ecosystem. The low surface energy marine coating is an entirely non-toxic alternative, which reduces the adhesion strength of marine organisms, facilitating their hydrodynamic removal at high speeds. In this paper, the novel low surface energy non-toxic marine antifouling coatings were prepared with modified acrylic resin, nano-SiO₂, and other pigments. The effects of nano-SiO₂ on the surface structure and elastic modulus of coating films have been studied, and the seawater test has been carried out in the Dalian Bay. The results showed that micro-nano layered structures on the coating films and the lowest surface energy and elastic modulus could be obtained when an appropriate mass ratio of resin, nano-SiO₂, and other pigments in coatings approached. The seawater exposure test has shown that the lower the surface energy and elastic modulus of coatings are, the less the marine biofouling adheres on the coating films. Supported by High-Tech Research and Development Program of China (Grant No. 2004AA001520)     

蓝藻水华衍生的微囊藻毒素污染及其对水生生物的生态毒理学研究

富营养化导致的蓝藻水华频发,引发各种衍生物污染,严重时造成重大生态灾害事件,甚至危及人类健康。其中微囊藻毒素以其毒性大、分布广和结构稳定的特点,成为水环境中常见的潜在危害物质,它主要由微囊藻产生,是一类具有多种异构体的环状七肽物质。本文根据微囊藻毒素污染现状及其水生生态毒理学研究的最新研究进展,介绍了微囊藻毒素的理化性质及其产生、迁移和转化,在我国天然水体、水库源水和饮用水中的污染现状以及部分水产品中的微囊藻毒素累积情况,较全面地评述了微囊藻毒素的分子致毒机理以及对水生生态系统的重要组成成分--常见水生植物和鱼类的生态毒理学效应,并提出了该领域未来研究的主要方向。     

Speciation of butyltin compounds by on line HPLC-ETAAS

Speciation of butyltin compounds by liquid chromatography coupled to electrothermal atomic absorption spectrometry of toluene solutions containing tropolone is applied to sediment samples. Tributyltin and dibutyltin may be determined at concentrations as low as a few ng · g^–1. Monobutyltin is strongly retained, tetrabutyltin is not separated from tributyltin.     

Recovery of all species from photolytic degradation of tributyltin compounds TBTX (X = Cl,OSn Bu3)

Malformations in shellfish have been reported by many authors. They attributed the cause of the deformity to the presence in water of organotin compounds used in the formulation of antifouling paints, for example bis(tributyltin) oxide (TBTO) and tributyltin chloride (TBTC). The behaviour of these compounds has been examined under abiotic laboratory conditions. The influence of many parameters such as sunlight, pH, oxygen, salinity have been examined. The degradation compounds obtained have been identified: (1) In the gas phase two major products, butene-1 and buetene-2, are observed with consumption of oxygen; (2) In the liquid phase, three main products are obtained, butanol-1, butanol-2 and butanone 2. The identified products represent a small part of the total concentration, suggesting a competing process such as formation of butyltin polymers; (3) In fresh water an amorphous solid phase is observed while in seawater a white cristalline precipitate appears.     

Analytical method development for the determination of four biocides used in antifouling paints in estuarine waters and sediments by gas chromatography-mass spectrometry

Summary Irgarol 1051, chlorothalonil, dichlofluanid and diuron are biocides utilised in antifouling paints as alternatives to organotin compounds, after restrictions imposed in the use of tributyltin in 1987. Effective analytical methods for the simultaneous determination of these four biocides in waters and sediments have been developed and method performance data are presented. Quantification is by gas chromatography—electron ionisation mass spectrometry (GC-EI-MS). The method involves the simultaneous extraction of the biocides from water with dichloromethane or from sediments with dichloromethane and acetone. For the determination of diuron the extract was methylated prior to GC analysis to avoid thermal degradation in the instrument. The method was applied to water and sediment samples spiked with the biocides. The highest detection sensitivities were achieved in the selected-ion monitoring (SIM) mode. Recovery studies were performed at 20, 2 and 1 ppb for all biocides in water and 400, 40 and 20 ppb in sediments. The percentage recoveries ranged between 90 and 100% for waters and 80 and 90% for sediments. Seven determinations were made at each concentration level along with a procedural blank. The quantification limit of the method was around 0.2 ppb for water and 5 ppb for sediments depending on the individual compound.     

The effects of short‐term changes in environmental parameters on the release of biocides from antifouling coatings: cuprous oxide and tributyltin

Current and forthcoming UK and European legislation requires environmental risk assessment of antifouling paints. For assessments to be carried out successfully, the leaching rate of biocides from antifouling paints should be determined. Current methods for the measurement of biocide leach rate have been shown to be very susceptible to changes in parameters such as pH, salinity and temperature. Using apparatus designed to simulate environmental conditions the effect of short‐term changes in salinity, pH, temperature, suspended particulate matter and simulated vessel speed on cuprous oxide and tributyltin (TBT) leaching from self‐polishing antifouling paint was investigated. No effect on copper leaching was observed over a wide range of environmentally relevant conditions, whilst vessel speed was the only parameter found to influence TBT release rates significantly. It is suggested that the decrease observed may be due to the formation of a boundary layer which slows down the release of TBT from the paint surface. The environmental authenticity of this observation and its possible implications for the environmental risk assessment of TBT are discussed. Copyright © 1999 Crown Copyright.     

Organotin antifouling paints and their alternatives

Tributyltin and triphenyltin compounds have excellent biocidal properties and almost all vessels in the world have used these paints since early in the 1960s. Contrary to expectation, as shown by experimental data at the beginning of organotin chemistry, triorganotins are exceptionally stable in the sediment or in dark places in the deep sea. Since triorganotins do not decompose rapidly in seawater, many incidences of deformities in some shellfish have been linked to their presence, even when present at extremely low concentrations. Alternative tin‐free antifoulants containing other biocides, such as copper compounds and organic compounds, have been developed and used since the late 1980s. Some nations have already banned the use of organotin antifouling compounds for small vessels, and in 2001 the International Maritime Organization decided to ban completely the use of the organotin compounds from the year 2003. Therefore, it is necessary to find economically and environmentally better biocidal substances as soon as possible. Moreover, the development of antifoulants containing environmentally safe natural products, fouling release coatings, electroconductive coatings, etc. have long been anticipated from the new point of conservation of the world marine environment. Copyright © 2003 John Wiley & Sons, Ltd.     

Micro-Encapsulation and Antifouling Coatings: Development of Poly(lactic acid) Microspheres Containing Bioactive Molecules

Summary: Environmental legislation compels marine paints companies to develop non toxic antifouling coatings respecting ecosystems. In this work, biodegradable polymers are used to conceive delivery systems with a lifetime of many months. For this purpose, chlorhexidine was encapsulated in poly(L-lactide) microspheres and incorporated in antifouling formulations. The characterization (encapsulation yield, surface morphology, particle size) and antibacterial activity (bacteriostatic and bactericidal effects) of microspheres were carried out by using scanning electronic (SEM) and confocal laser scanning microscopies (CLSM). The results indicate a good ability of loaded microspheres to be formulated even though an excellent activity against selected marine bacteria is conserved. This is a promising approach to develop biodegradable antifouling paints based on non toxic molecules and bioactive surfaces.     

Acute and chronic effects of tributyltin on the Chinese rare minnow (<Emphasis Type="Italic">Gobiocypris rarus</Emphasis>)

The acute (12 h) and chronic (7 or 14 d) effects of tributyltin chloride (TBT) on a new type of test fish, the Chinese rare minnow (Gobiocypris rarus), have been studied. High accumulation of the pollutant in the fish muscle and obvious changes in hepatosomatic index and gonad somatic index were observed after exposure. The ultrastructural findings show a series of pathological changes existing in the exposed gill cells and hepatocytes, which demonstrates the toxicity effects of tributyltin compounds on aquatic organisms. The results clearly show that the Chinese rare minnow is a new sensitive test fish material, whose exposure system is suitable for the extensive organometallic toxicity studies.     

Analytical methods for antifouling booster biocides determination in environmental matrices: A review

Since the discovery of their toxicity to aquatic environments, antifouling booster biocides (ABBs) have been widely researched and detected at trace levels in diverse environmental compartments including water, sediment, and, less frequently, biota. Hence, the reliable assessment of environmental risks posed by ABBs requires the development of analytical methods sufficiently robust, accurate, and precise for the simultaneous trace-level determination of ABBs. Herein, we summarize outstanding sample preparation procedures for the analysis of main ABBs in environmental matrices, describing techniques ranging from traditional extraction methods to novel miniaturized and micro-extraction ones, which have recently received much attention due to their reduced number of steps, low operational cost, and greater respect for the environment. The main applied chromatographic-based methods coupled to different detection techniques are also addressed. Despite the recent development of numerous ABBs determination methods, this topic continues to draw attention because of the lack of standardization among methods, despite legislation set up maximum standards levels for selected ABBs, and the need to monitor ABB transformation products for a reliable ecological risk assessment.