Organotins (TBT and DBT) in water, sediments, and gastropods of the southern Venice lagoon (Italy)

The release of tributyltin (TBT) from maritime traffic represents one of the main problems of direct, diffuse, and continued contamination of the marine environment. In the present survey, the concentrations of TBT and dibultytin (DBT) in brackish waters, sediments, and the gastropods Nassarius nitidus were evaluated in order to estimate the contamination of the southern part of the Venice lagoon. TBT and DBT were determined by GC-MS/MS. Recent contamination of TBT was found in brackish waters near marinas, whereas the highest concentrations of TBT and DBT were observed in surface sediments at dockyards and harbours. High content of organotin in the gastropods sampled near the dockyards, harbours, and marinas showed a mobilisation from the sediments through the food web. The present study allowed assessment of whether, despite the ban on the use of TBT paints, waters, sediments, and biota were still being contaminated by organotin compounds in the southern Venice lagoon.     

A survey of antifoulants in sediments from Ports and Marinas along the French Mediterranean coast

Due to deleterious effects on non-target organisms, the use of organotin compounds on boat hulls of small vessels (<25 m) has been widely prohibited. The International Maritime Organisation (IMO) resolved that the complete prohibition on organotin compounds acting as biocides in antifouling systems should commence in 2008. As a result of restrictions on the use of organotin based paints, other antifouling formulations containing organic biocides have been utilised. This survey was conducted to assess the contamination of replacement biocides in the marine environment following the ban of TBT-based paints. Surface sediments samples were collected in the major ports and marinas along the France Mediterranean coastline (Cote d’Azur) and analysed for organotin compounds, Irgarol 1051, Sea-nine 211^TM, Chlorothalonil, Dichlofluanid and Folpet. Every port and marina exhibited high levels of organotin compounds, with concentrations in sediments ranging from 37 ng Sn g⁻¹dry wt in Menton Garavan to over 4000 ng Sn g⁻¹dry wt close to the ship chandler within the port of Villefranche-sur-Mer. TBT degradation indexes suggested that fresh inputs are still made. Among the other antifoulants monitored, only Irgarol 1051 exhibited measurable concentrations in almost every port, with concentrations ranging from 40 ng g⁻¹dry wt (Cannes) to almost 700 ng g⁻¹dry wt (Villefranche-sur-Mer, ship chandler).     

Accumulation of butyltins in muscle tissue of chinook salmon reared in sea pens treated with tri-n-butyltin

Muscle tissue of chinook salmon, Oncorhyncus tshawytscha, reared for 3 to 19 months in sea pens treated with an antifouling biocide, tri-n-butyltin (TBT), contained organotin concentrations of 0.28–0.90 μg g⁻¹ (as TBT). Organotins are present in some pen-reared salmon sold in the United States: eleven of 15 salmon advertised as aquaculture products and purchased from public markets contained organotin concentrations of 0.081–0.20 μg g⁻¹. Most common cooking practices do not effectively destroy or remove butyltins from salmon muscle tissue. We believe this is the first evidence of entry of organotins into the human diet in the United States.     

Distribution of butyltins in the waters and sediments along the coast of India

Water and surface sediment samples were analyzed for butyltins (TBT, DBT, MBT) from various ports along the east and west coast of India. The total butyltin (TB) in water samples varied between ∼1.7 and 342 ng Sn l⁻¹, whereas for sediments it varied between below detection limit to 14861 ng Sn g⁻¹ dry weight of sediment. On an average Chennai port recorded the highest level of butyltins in the sediments while Paradip recorded the highest level of butylins in the waters. A fairly good relationship between the TB in the sediment and overlying water samples, as well as between organic carbon and TB, implicates the importance of adsorption/desorption process in controlling the levels of TBT in these port areas. In India the data on organotin pollution is very sparse; most of the port areas have been surveyed for butyltins for the first time during this study.     

The contribution of urban runoff to organic contaminant levels in harbour sediments near two Norwegian cities

The main aim of the present study was to compare the quality of particle emissions (urban runoff and settling particles in rivers and harbours) to the quality of top-layer bed sediments, for two Norwegian harbours (Oslo and Drammen). A sub-aim was to investigate whether non-industrial urban runoff contributed to the organotin load of sediments, apart from leaching from ship hulls. Time-integrated samples of stormwater runoff were obtained in an innovative manner, by sampling man-holes in the stormwater system. Settling particles were sampled with sediment traps. The study focused on PAHs, PCBs and organotin compounds. Contaminant levels were generally a factor of 2-10 (PAHs) and 3-30 (TBT) lower in emitted riverine and runoff particles than in top-layer bed sediments, except for PCBs in Oslo harbour (only 20-30% lower). Significant levels of tributyltin (TBT; median 140mug/kg) were shown in runoff particles, showing that TBT can also be emitted via urban sources, since the sampled man-holes were not in areas where dry-docking activities take place. Possible land-based TBT sources include long-lasting house paint and use of TBT as PVC stabilizer and timber preservative. Since there are ongoing emissions into the two studied harbour areas, it is concluded that the addition of an actively sorbing capping material such as activated carbon might be the best remediation alternative.     

Baseline of butyltin pollution in coastal sediments within the Basque Country (northern Spain), in 2007-2008

Tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT) were measured in surficial sediments at, the ports of Pasaia and Bilbao, together with other mid- and small-size harbours of the Basque Country (northern Spain), in 2007-2008. The highest values of the sum of the three measured butyltin species (3523-3640 ng g⁻¹, as Sn) were found at sampling stations near to shipyards located within the port of Pasaia. The highest value of TBT concentration (3143 ng g⁻¹, as Sn) was found at the marina of Getxo, in the port of Bilbao. The degree of TBT degradation varied greatly between sampling stations, being found to be generally higher in those sediments with higher values of redox potential and lower values of TBT concentration (normalized by organic matter content).     

TBT toxicity on the marine microalga Nannochloropsis oculata

Commercial antifouling formulations containing TBT are the major source of organotin contamination in coastal waters. In view of the persisting TBT residues (13 ng Sn l⁻¹) in the coastal waters of South Korea, an attempt has been made to evaluate the growth response and biochemical composition of laboratory-cultured Nannochloropsis oculata to TBT toxicity. It is evident that the persisting concentration level of TBT is high enough to cause adverse effect on the microalgal species. The EC₅₀ (24 h) was found to be at 0.89 nM level of TBT for this marine eustigmatophyte N. oculata. Photosynthetic pigment content was significantly affected. At elevated TBT concentrations of 1.0 nM, especially pronounced changes in biochemical composition was found. TBT tolerance of N. oculata and its growth as well as biochemical responses are discussed.     

TBT toxicity on the marine microalga Nannochloropsis oculata

Commercial antifouling formulations containing TBT are the major source of organotin contamination in coastal waters. In view of the persisting TBT residues (13 ng Sn l⁻¹) in the coastal waters of South Korea, an attempt has been made to evaluate the growth response and biochemical composition of laboratory-cultured Nannochloropsis oculata to TBT toxicity. It is evident that the persisting concentration level of TBT is high enough to cause adverse effect on the microalgal species. The EC₅₀ (24 h) was found to be at 0.89 nM level of TBT for this marine eustigmatophyte N. oculata. Photosynthetic pigment content was significantly affected. At elevated TBT concentrations of 1.0 nM, especially pronounced changes in biochemical composition was found. TBT tolerance of N. oculata and its growth as well as biochemical responses are discussed.     

Organotin levels in Nazaré canyon (west Iberian Margin, NE Atlantic) and adjacent coastal area

Organotin compounds (OTs) are ubiquitous in the marine environment and high concentrations (μg g(-1) range) in sediments from different coastal areas around the world have been reported. However, few reports have described the OTs contamination status in the offshore and deep sea environment. This work investigated organotin levels in Nazaré canyon for the first time. Levels of monobutyltin (MBT), dibutyltin (DBT), tributyltin (TBT), diphenyltin (DPT), triphenyltin (TPT), dioctyltin (DOT) and trioctyltin (TOT) were quantified in sediment samples from the upper flanks of the canyon and from the adjacent coastal area. TBT levels detected in the canyon flanks are about two to three orders of magnitude lower than those found in the coastal area. Nevertheless, when quantifiable, TBT levels in the canyon samples were higher than the Environmental Assessment Criteria set for TBT in sediments by the OSPAR Commission indicating that at those locations negative ecological impacts are likely to occur.     

A new bioassay for the inspection and identification of TBT-containing antifouling paint

Since the 1960s tributyl (TBT)-based antifouling paints are widely applied to protect ship’s hulls from biofouling. Due to its high toxicity to aquatic ecosystem most of the countries (28 nations in 2008) signed the AFS convention to control the use of harmful antifouling systems on ships. Nevertheless there is currently no simple method to control the presence of organotin in paint. In this study, we propose a bioassay based on the use of a recombinant bioluminescent bacteria to detect directly in paint the presence of TBT. We also propose a simple device as an inspection system to control the absence of organotin in the ship’s hull paint. The presence of organotin could be revealed in less than three hours.     

Trace elements in the sediments of a large Mediterranean marina (Port Camargue,France): Levels and contamination history

The study of trace elements (Cu, Zn, Pb, As, Hg) and butyltin concentrations in the sediments of Port Camargue enabled assessment of the levels and history of the contamination of the largest European marina linked with the use of antifouling paints. Surface sediments near the boat maintenance area were heavily contaminated with up to 1497 μg g⁻¹ of Cu, 475 μg g⁻¹ of Zn, 0.82 μg g⁻¹ of Hg, 94 μg g⁻¹ of Pb and over 10,000 ngSn g⁻¹ of tributyltin (TBT). High concentrations of Hg and TBT indicate ongoing sources of these elements despite the ban on their use as biocides in paints. Sediment cores provided records of contamination since 1969. The peak concentrations of As, Hg, Pb and TBT in the sediment profile reflect their presence on boat hulls when the marina was built at the end of the 1960s. Degradation of TBT in the sediments near the boat maintenance area is slow compared to other less contaminated area of the marina.     

Assessment of organotin (butyltin species) contamination in marine biota from the Eastern Aegean Sea, Turkey

The marine environment continues to be adversely affected by tributyltin (TBT) release from maritime traffic. Therefore the concentrations of TBT, dibutyltin (DBT) and monobutyltin (MBT) were measured in barnacles, mussels and fish along the Eastern Aegean coastline. The average concentrations of TBT ng Sn g⁻¹ were found to be 235 in fish, 116 in mussels and 635 in barnacles. The highest concentrations of TBT, DBT and MBT were observed in the barnacles which had been sampled in marinas and harbors. All mussels sampled showed values of TBT + DBT, which were below the “tolerable average residue level (TARL)” as currently accepted. This indicates a lack of risk to the consumer. However, 7 out of the 15 fish sampled displayed TBT + DBT levels above the TARL, which indicates that a fish consumer group may be at risk. Barnacles have high potential as biomonitors for the presence of organotin in the Aegean Sea.     

Organotin and total tin in coastal waters of Southwest England

Samples of seawater from sites along the southwest coast were collected during 1984 and analysed for total tin and organotin by flameless atomic absorption spectro-photometry. Organotin concentrations were below detection limits (0.10 μg l^?1 TBTO) at all marina sites, but higher concentrations were found in harbour waters, the highest value being 0.88 μg l^?1 TBTO at Plymouth (Sutton harbour). The fact that organotin levels may occasionally exceed some toxicological threshold concentrations suggests that biological water quality may sometimes be depressed.     

Magnetic characteristics of sediment grains concurrently contaminated with TBT and metals near a shipyard in Busan,Korea

Bottom sediments near shipyards are often susceptible to receiving accidental spills of TBT and metals or their degradation products from hull scraping of antifouling system paints applied prior to 2008, when the AFS Convention 2001 was not in force. We investigated TBT and metal contamination of sediments near the shipyards of a small marina located in Busan, Korea and found that they were highly contaminated with TBT, Cu, and Zn. To better understand the environmental impacts and to make an optimal remediation plan, we characterized individual antifouling fragments in terms of metal and TBT contents, magnetic properties, and grain-size. Coarse-sized individual antifouling fragments exhibited simultaneously high levels of TBT, metals and high magnetic susceptibility, and appeared to be a major source of pollution in the sediment. Therefore, magnetic separation in combination with size-separation appears to be a cost-effective remediation method to remove the TBT and metals from contaminated shipyard sediments.     

High mortality of the larvae of the common mussel at low concentrations of tributyltin

Laboratory reared veliger larvae of the common mussel Mytilus edulis were grown for 15 days in filtered seawater containing 10 μg l^?1, 1 μg l^?1 and 0.1 μg l^?1 tributyltin oxide (TBTO), the biocide in recent antifouling paint formulations. No larvae survived longer than 5 days in 10 μg l^?1 TBTO or 10 days in 1 μg l^?1 TBTO. Approximately half the larvae subjected to 0.1 μg l^?1 TBTO were dead by day 15 (approximate 15 day LC₅₀ = 0.1 μg l^?1 TBTO) and most of the surviving larvae were moribund and had grown significantly more slowly than controls. It is noted that current recorded levels of TBT at several UK estuarine sites are higher than 0.1 μg l^?1 and there has therefore probably been a high mortality of mussel larvae at such sites. The results are discussed in relation to the reported short-term toxicity of organotins to other marine organisms and the value of carrying out longer-term tests at low levels of TBT is pointed out.     

Field Study of Enhanced TCE Reductive Dechlorination by a Full‐Scale Whey PRB

This study evaluates the efficiency of a full‐scale, 81 m‐wide permeable reactive barrier (PRB) configured by injection of dairy whey in the downgradient region of a contaminant source zone to enhance the in situ biodegradation of high concentrations (10² to 10³μg/L) of chlorinated ethenes (CEs). Ten biannual whey injections were completed in a 3.5‐year pilot phase and 1.5‐year operational phase. Improved and sustained dechlorination was observed at extraction/injection and downgradient wells in the fully‐operational phase, when dried whey masses were increased from 13.6 kg to 230–360 kg, whey slurry volumes were increased from 2300 L to 307,000–480,000 L, and extraction/injection well loops were employed for the application of whey. At extraction/injection wells, CEs decreased to low (≤10 μg/L) or undetectable levels. At downgradient wells, average trichloroethene concentrations decreased, by as much as 100% (from ≤384.2 during the pilot phase to ≤102.6 μg/L during the operational phase), while average cis‐dichloroethene concentrations decreased by as much as 57.5% (from ≤6466.1 to ≤4912.2 μg/L). Downgradient vinyl chloride averages either increased by as much as 63.8% (from ≤859.6 to ≤1407.9 μg/L) or decreased by 64.0% (from 1375.4 to 880 μg/L). Downgradient ethene + ethane averages increased by as much as 73.2% (from ≤1145.3 to ≤1347.1 μg/L). On the basis of the 2008 average market price, the estimated material cost of whey is $1.96/kg organic carbon or, for the configuration of an 81 m PRB by biannual application of 300 kg whey, $325/year. Carbon substrate cost comparisons and implications for efficient in situ treatment design are discussed.     

A study on the treatment of antifouling paint waste from shipyard

A study on the treatment of antifouling paint waste from shipyards, including sandblast waste and ship hull washing wastewater, was performed. The sandblast waste could be effectively detoxified by heat treatment, and the efficiency was affected by the temperature of the heating vessel and treatment time. The removal efficiency of total organotin compounds from the sandblast waste was over 99% at 1000 °C and treatment for 1 h. For the treatment of ship hull washing wastewater by the solvent extraction, ship diesel was a good solvent for the tributyltin (TBT) extraction, and the proper amount of solvent was about 10 mL for TBT extraction from 1 L of wastewater. The extraction efficiency of TBT was significantly affected by the agitation intensity. The TBT in the wash wastewater was rapidly extracted within 1 h. The level of the TBT residual in the wastewater extracted for 1 h was 2.8 μg L⁻¹, and this was further decreased to 0.8 after 5 h extraction.     

Butyltin compounds,sterility and imposex assessment in Nassarius reticulatus (Linnaeus, 1758), prior to the 2008 European ban on TBT antifouling paints,within Basque ports and along coastal areas

Levels of imposex (superimposition of male characters, upon females) and the presence of sterile females are assessed in the gastropod Nassarius reticulatus (L.), at 35 locations in the Basque Country. At 18 of these localities, organotin bioaccumulation (tributyltin (TBT); dibutyltin; monobutyltin) was evaluated, using isotope dilution GC–ICP–MS. Higher imposex levels and TBT body burden were found in confined harbours, with large vessel traffic or the presence of an offshore fleet. The highest values were found for the port of Pasaia, near to a shipyard (a relative penis size index of up to 92%, and TBT body burden up to 405 ng g^?1 – given on a dry weight basis as Sn). Imposex effects were evaluated also in parasitized females, at some of the sampling sites. The percentage of presence of c-type Vas Deferens sequence stages (i.e., with vas deferens beginning at the oviduct opening) was higher in parasitized females. In turn, there was an absence of highly convoluted oviduct in parasitized females.     

Possible effects of organotins on scallop recruitment

The adult populations of the scallop (Pecten maximus) and of flame shells (Lima hians) have declined in the North Water of Mulroy Bay on the north coast of Ireland. Settlements of these and some other bivalve species either failed or were reduced. These events relate well to the first introduction and subsequent increased use of organotin net-dips on salmonid farms in this Bay. The last use of these net-dips was during the spring of 1985. In 1986 these was a good settlement of scallops, and settlements of other bivalves were recorded except for flame shells. Levels of TBT in adult scallop tissue in the North Water are high, 0.7 μg g⁻¹ wet wt; levels determined in other species were much lower. Pacific oyster (Crassostrea gigas) shell thickening was used to monitor the presence of organotins in a number of areas including Mulroy Bay. In Kilkieran Bay, an area having a scallop fishery, this was greatest at the innermost station, suggesting higher levels there. Shell thickening and organotins in Pacific oysters were also measured in Cork Harbour.     

Assessment of organotin contamination in marine sediments and biota from the Gulf and adjacent region

Butyltin species were measured in sediments from coastal locations in the Gulf and Gulf of Oman. Both butyltin and phenyltin species were measured in biota samples from four countries in this region. With tributyltin (TBT) concentrations up to 60 ngSng(-1), some sediments could be classified as contaminated (i.e. TBT>1.3 ngSng(-1)), namely Dukhan (Qatar), the BAPCO industrial complex and Askar (Bahrain), and Hilf and the Raysut Port Area (Oman). Higher concentrations of total butyltins were found in oysters relative to fish, but ranging from 6.5 to 488 ngSng(-1) dry weight they are nonetheless relatively low. Diphenyltin and triphenyltin were found in some fish and bivalves from the Gulf, but not in biota from the Gulf of Oman. The environmental levels of organotin species are comparatively low by global standards and pose no immediate public health problems.