Tolerable Average Residue Level Research Articles

Distribution of antifouling biocides in a coastal area of Tanabe Bay, Japan

AbstractTributyltin (TBT) and triphenyltin (TPT) concentrations in water samples from Tanabe Bay were found to range from 4–28 ng l−1 and 3–7 ng l−1, respectively. In fishing ports, the concentrations of TBT in surface water were similar to those in bottom water. However, in aquafarming areas with poor flushing, the concentrations of TBT in bottom water were higher than those in surface water. This suggested that the TBT in water samples is re-eluted from sediment. No difference in the concentration of TPT was observed between the surface and bottom waters. The concentrations of TBT and TPT in sediment samples ranged from 3–23 μg kg−1 dry weight and 2–37 μg kg−1 dry weight. TBT and TPT concentrations ranged from 3.1–100 μg kg−1 and 3.1–7.2 μg kg−1 in oysters and gastropods, and from 1.1–4.9 μg kg−1 and ＜0.2–3.9 μg kg−1 in fish, respectively. Organotin concentrations in biota were lower than the tolerable average residue levels (TARLs). Alternative biocides – i.e. diuron, chlorothalonil, dichlofluanid, irgarol 1051 and Sea-Nine 211 – were also detected in surface water, and chlorothalonil and irgarol 1051 were detected in sediment. The concentrations of these compounds in surface water and sediment were lower than those reported previously. Dichlofluanid, chlorotharonil and irgarol 1051 were also found at low levels in oysters and gastropods, and at ranges of 325–339 μg kg−1, 268–291 μg kg−1 and 43–49 μg kg−1, respectively, in fish; the concentrations in fish were close to the TARL levels.

Butyltin compounds in fishes commonly sold in Taiwan markets

Fishes commonly consumed in Taiwan were purchased from four fish markets at seasonal intervals in 2006 in order to monitor the butyltin residues, including monobutyltin (MBT), dibutyltin (DBT), tributyltin (TBT), and tetrabutyltin (TeBT), in fishes caught along the west coast of Taiwan. Concentration of MBT, DBT, TBT, and TeBT in the muscle or the internal organ of these fishes were in the range of n.d.-949.2±49.1, n.d.-56.2±7.9, n.d.-70.8±10.0, and n.d.-103.8±76.9 ng/g (wet weight), respectively. Owing to the toxicological similarity between DBT and TBT, total concentrations of DBT plus TBT in the muscle or the internal organ were taken as the standard for the residue level of butyltins and they were found lower than the tolerable average residue level (TARL) of 175.4 ng/g (wet weight). Therefore, butyltin levels in fish from Taiwanese markets are not a matter of concern for public health.

Health risk assessment of the intake of butyltin and phenyltin compounds from fish and seafood in Taiwanese population

Organotin compounds have been applied as stabilizers for PVCs, fungicides, and pesticides, those can enter water systems through antifouling paints on ships as well as from diverse industrial and agricultural processes. This study aims to monitor the background levels of six organotins in 200 fishery products. In the current study, the high organotin levels are over tolerable average residue levels in Taiwan. Phenyltins (PTs) levels in fish and seafood are higher than butyltins (BTs). Risk assessment showed that 95% upper confidence limits of the hazard index (HI) of organotins were almost all over 1, indicating that there are probability of health impacts for organotin consumption in Taiwanese consumers. Those who consume higher amounts of seafood and fishery may be at a higher risk of health issues, but the data indicate that organotin levels have become controlled in recent years as compared with health risk data published in 2006.

Butyltin compounds in sediment and biota from the lagoon of Bizerte (northern Tunisia): Potential risk for consumers?

ABSTRACTLevels of butyltins (BTs) were monitored in sediment samples and in seven fish species (Boops boops, Diplodus sargus, Sarpa salpa, Serranus scriba, Spicara smaris, Trachurus draco, and Trachinus mediterraneus), five bivalve species (Cerastoderma glaucum, Chlamys flexuosa, Mytilus galloprovincialis, Pinna nobilis, and Ruditapes decussatus), two gastropod species (Bolinus brandaris and Hexaplex trunculus), cuttlefish (Sepia officinalis), and shrimp (Penaeus notialis), most of which are commonly consumed in Tunisia. Samples were collected from Bizerte lagoon during March 2012. Average concentrations of total BTs found in sediment and the muscle of fishes, bivalves, gastropods, cuttlefish, and shrimp were 17.7, 11.5, 31.8, 36.9, 8.1, and 9.4 ng Sn g−1 dw, respectively. The calculation of tolerable average residue levels and non-cancer hazard quotient for tributyltin (TBT) showed that daily exposure of these seafood to TBT is unlikely to cause any deleterious effects to humans, thus indicating that consumers may not be at risk through the inclusion of these species in their regular diet.

Speciation analysis and characterisation of arsenic in lavers collected from coastal waters of Fujian, south-eastern China

Laver samples (Porphyra haitanensis) were collected from the coastal waters of Fujian province, south-eastern China and then the speciation characteristics of arsenic in the samples were studied in detail. These laver samples contained five arsenical species, namely arsenobetaine, monomethylarsonic acid, As(V) and two kinds of arsenic-containing ribosides (arsenosugars), with a relatively high concentration of total arsenic in the range of 28.85–63.03μgAs/g dried weight. DMAsSugarMethoxy was found to be the predominant species of arsenic in lavers, accounting for 90–98% of total arsenic. As3+ was not detected and the level of inorganic arsenic was much lower than the national tolerable average residue level (TARL), suggesting that the lavers are safe for consumption.

Organotin compounds in olive flounder Paralichthys Olivaceus and flathead mullet Mugil cephalus from Korean coastal waters

Concentrations of organotin compounds (OTCs) were measured in the muscle and liver of two fish species (Paralichthys Olivaceus and Mugil cephalus) collected in the six developed coastal regions of Korea: Incheon, Gunsan, Yeosu, Masan, Pohang and Jeju. Concentrations of butyltin compounds (ΣBTs) in the muscle and liver of the two fish species were detected in the range of 1.7–28.8 (mean: 8.8) ng/g-wet wt. as Cl and 18.7–5,096.9 (mean: 832.6) ng/g-wet wt. as Cl, respectively. Concentrations of phenyltin compounds (ΣPTs) ranged <0.1–72.5 (mean: 10.89) ng/g-wet wt. as Cl in the muscle and <0.1–316.3 (mean: 28.0) ng/gwet wt. as Cl in the liver. Concentrations of OTCs in the liver were higher than those of OTCs in the muscle. The compositions of ΣBTs in the muscle and liver were different from each other, but those of ΣPTs were similar. Tributytin (TBT) and triphenytin (TPT) levels in the two fish species collected from Korean coastal waters were significantly lower than the tolerable average residue level (TARL) estimated based on the tolerable daily intake (TDI).

Butyltin Compounds in Fish Commonly Sold in North of Iran

Levels of tributyltin (TBT) and its degradation products, mono (MBT) and dibutyltin (DBT), were monitored in fish commonly consumed in Iran. Samples were purchased from fish markets at seasonal intervals in 2010 along the North coast of Iran. Concentration of MBT, DBT and TBT in the muscle of these fish were in the range of n.d. -1.01±0.84, n.d. -0.33±0.26 and n.d. -4.31±0.95 ngg(-1) (wet weight), respectively. Residue levels of butyltins were found lower than the tolerable average residue level of 100 ngg(-1) (wet weight).

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 ngSng−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.

Assessment of Antifouling Biocides Contaminations in Maizuru Bay, Japan

The concentrations of organotin compounds in the aquatic environment of Maizuru Bay and their spatial distribution are discussed. The concentrations of tributyltin (TBT) compounds in water samples ranged from 0.001 to 0.002 microg l(-1), and monobutyltin compounds were the dominant species among the butyltin compounds. TBT concentrations in Maizuru Bay are low compared with other coastal waters of Japan. Drastic differences in TBT concentrations were not observed among the Maizuru Bay sites. Phenyltin compounds were not detected in the water samples. Concentrations of TBT and triphenyltin (TPT) in sediment from Maizuru Bay ranged, respectively, from 0.9 to 11 microg kg(-1), from 0.2 to 17 microg kg(-1) dry weight (dw). TBT concentrations in Maizuru Bay were lower than those in other coastal areas of Japan. TPT concentrations were greater than TBT concentrations in the fishing port. The concentrations of TBT and TPT in blue mussels (M. galloprovincialis) from Maizuru Bay were in the range of 2.4 to 9.3 microg kg(-1) and 0.2-13 microg kg(-1) wet weight (ww), respectively. A tolerable average residue level (TARL) was estimated at 74.8 microg kg(-1) from a tolerable daily intake (TDI) of 0.25 bis(tributyltin)oxide microg kg(-1) body weight day(-1). TBT concentrations detected in blue mussel samples were lower than the TARL values. The acceptable concentration of TPT, which were calculated using acceptable daily intake instead of TDI, was 127 microg kg(-1). Concentrations of TPT in blue mussel samples were also lower than the TARL. TBT compounds in blue mussel samples were at similar levels among the various sampling sites, indicating that TBT is not currently being used in ship hull paints; the ratios of degradation products of TBT and TPT were greater than those of the parent compounds. Concentrations of alternative biocides in water samples were also investigated in the bay. Although Sea-Nine 211, M1, and Pyrithiones were not detected, Diuron and Irgarol 1051 were detected at 0.010-0.257 and at 0.002-0.018 microg l(-1), respectively. Concentrations of Diuron were great in the shipping route and near the shipyard, whereas the concentration of Irgarol 1051 was great at the fishing port. Concentrations of Diuron and Irgarol 1051 in sediment from Maizuru Bay ranged, respectively, from <0.08 to 12, from <0.08 to 9.8 microg kg(-1) dw, respectively. Despite being a semi-enclosed bay, we found that sediment in Maizuru Bay is not contaminated by alternative biocides to the degree found in other coastal areas. Copper concentrations of sediment were at ordinary levels, and those of blue mussels were slightly lower than those reported previously in other coastal areas of Japan. In both the sediment and blue mussels, there was no correlation between the presence of copper and antifouling biocides.

Organotin levels in seafood from Portuguese markets and the risk for consumers

Because of their ubiquity in the aquatic environment, the antifouling agent tributyltin (TBT) and other organotins (OTs) accumulate through the food chain, resulting in the occurrence of OTs in seafood products. Despite a high number of studies on the negative impact of TBT in female prosobranch gastropods, few works exist in Europe reporting the levels of these compounds in edible parts of marine organisms used in Human diet. Therefore, within the scope of an EU project OT-SAFE the levels of several OTs were evaluated in the most relevant seafood products for Portuguese consumers. Butyltins (BTs) have been detected in all analysed groups (fish, crustaceans, bivalves, cephalopods), whereas triphenyltin, tricyclohexyltin, monooctyltin and dioctyltin could not be detected and tetrabutyltin was present above detection limits in a single sample. In general, levels of BTs in edible parts of fish, crustaceans and cephalopods collected in Portuguese markets during this study are in the lower range of that reported for these animal groups from other locations (i.e. below 30ngg−1 wet weight). In contrast, moderate to high concentrations have been observed in bivalves (up to 275ng TBTg−1 wet weight). While most samples showed TBT plus DBT levels below the tolerable average residue levels (TARL), which may indicate low risk for consumer, four bivalve samples displayed BT levels above TARL, thus indicating that higher bivalve consumer groups may be at risk. The results found are discussed in relation to the potential risk for consumers and integrated with recent finds on the molecular targets of OTs in mammals.

MONITORING OF BUTYLTIN COMPOUNDS IN THE AQUATIC ENVIRONMENTS OF THE PHILIPPINES

This article provides a comprehensive review of the contamination by Butyltin compounds (BTs) and its possible implications on the marine and coastal environments of the Philippines. Butyltin compounds were detected in mussels from all the sampling locations investigated as part of the monitoring surveys under the Asia-Pacific Mussel Watch (APMW) Program conducted in the late 1990s. BTs were detected in green mussels collected from all the aquaculture sites in the country, suggestive of considerable widespread pollution by BTs in the coastal waters. Among BTs, TBT was detected at all locations at relatively higher concentrations, whereas the concentrations of DBT and MBT were lower. This could be indicative that green mussels have limited ability of metabolize TBT to DBT and MBT. In addition, this result may be suggestive of fresh TBT inputs into the aquatic environments and the presence of recent sources along the coastal waters. Concentrations of 0 BT in green mussels were reported up to 790 ng/g wet weight in a site where intensive maritime activities are occurring. Mussels from rural areas contained TBT at lower proportions indicating that TBT usage as antifouling agents is minimal. Tolerable average residue level (TARL) for seafood in the Philippines was estimated at 173 ng/g wet weight for an average person weighing 60kg. Concentrations of TBT or the sum of TBT and DBT in some green mussels analysed revealed that some values exceeded TARL level, which could suggest that humans consuming this seafood from areas with high BTs contamination could be at risk from elevated exposure to BTs. Similarly, BTs were detected in all the skipjack tuna collected, suggestive of the widespread contamination even in offshore waters and open seas on a global scale. Skipjack tuna collected from the offshore waters of the Philippines revealed considerable levels (up to 220 ng/g wet weight), with high percentages of BTs in total tin (0Sn: inorganic tin + organic tin) in the liver tissues. This finding seems to suggest that the anthropogenic BTs represent the major source of Sn accumulation in skipjack tuna. On the other hand, relatively low concentrations of BTs were found in the liver of cetaceans from the coastal waters of the Philippines, which ranged 42-98 ng/g wet weight. Significantly lower hepatic BT concentrations in cetaceans in tropical waters were noted compared with those inhabiting temperate waters proximal to developed nations. This result could imply smaller usage of BTs in the Philippines at least at the present.

Contamination Profiles of Antifouling Biocides in Selected Coastal Regions of Malaysia

The concentrations of butyltins (BTs) in sediment from Peninsular Malaysia along the Strait of Malacca and their spatial distribution are discussed. The concentrations of BTs were high in the southern part of Peninsular Malaysia where there is a lot of ship traffic, because trade is prosperous. The concentrations of monobutyltin (MBT), dibutyltin (DBT), and tributyltin (TBT) in sediment from the coastal waters of Peninsular Malaysia were in the range 4.1-242 microg/kg dry weight (dw), 1.1-186 microg/kg dw, and 0.7-228 microg/kg dw, respectively. A higher percentage of TBT was observed in the area where TBT concentrations were high. The concentrations of monophenyltin (MPT), diphenyltin (DPT), and triphenyltin (TPT) were in the range <0.1-121 microg/kg dw, 0.4-27 microg/kg dw, and 0.1-34 microg/kg dw in sediment from Peninsular Malaysia, respectively. MPT was the dominant phenyltin species. MBT, DBT, and TBT in green mussel (Perna viridis) samples were detected in the range 41-102 microg/kg, 3-5 microg/kg, and 8-32 microg/kg, respectively. A tolerable average residue level (TARL) was estimated at 20.4 microg/kg from a tolerable daily intake (TDI) of 0.25 microg TBTO/kg body weight/day. The maximum value of TBT detected in green mussel samples was the value near the TARL. TPTs were not detected in green mussel samples. The concentrations of Diuron and Irgarol 1051 in sediment from Peninsular Malaysia were in the range <0.1-5 microg/kg dw and <0.1-14 microg/kg dw, respectively. High concentrations of these compounds were observed in locations where the concentrations of TBT were high. Sea Nine 211, Dichlofluanid, and Pyrithiones were not detected in sediment. The concentrations of antifouling biocides in Melaka and the Strait of Johor were investigated in detail. BTs were found in similar concentrations among all sampling sites from Melaka, indicating that BT contamination spread off the coast. However, Sea Nine 211, Diuron, and Irgarol 1051 in the sediment from Melaka were high at the mouth of the river. BT concentrations at the Strait of Johor were higher than those in Peninsular Malaysia and Melaka and were high at the narrowest locations with poor flushing of water. The concentrations of antifouling biocides were compared among Malaysia, Thailand, and Vietnam. A higher concentration and wide variations of TBT and TPT in sediment from Malaysia were observed among these countries. The Irgarol 1051 concentrations in sediment from Malaysia were higher than those in Thailand and Vietnam.

Time trend of Butyl- and Phenyl-Tin contamination in organisms of the Lagoon of Venice (1999–2003)

In the period 1999-2003 a monitoring study on the accumulation of organotin compounds in edible organisms in the Lagoon of Venice was conducted. Butyl and Phenyl derivatives were determined in pooled samples of Mytilus galloprovincialis and Tapes spp. with the aims of assessing organotin contamination in the Lagoon of Venice in the period just preceding their ban in Europe, monitoring the concentrations in organisms with a high commercial use, evaluating a potential hazard for human health due to seafood and identifying the possible contamination sources. Sampling stations (up to 20) were distributed around the Lagoon and particularly concentrated in the area close to the town of Chioggia. Significantly higher (analysis of variance (ANOVA), p < 0.05) tributyltin (TBT) concentrations were found in mussels (from 38 +/- 8 to 6,666 +/- 1,333 microg kg(-1) d.w., as TBT(+)), than in clams (from 6 +/- 1 to 2,256 +/- 451 microg kg(-1) d.w., as TBT(+)). During the 3 years of the survey no increase in average concentrations of the butyltin compounds (tributyltin (TBT) + dibutyltin (DBT) + monobutyltin (MBT)) was observed (ANOVA, p > 0.05) in either species. Furthermore, by analyzing the entire data set, it is evident that most stations show analogous concentrations in the 3 years for both species, whereas few have anomalously higher concentrations. If organotin concentrations in specimens from some sites are compared with the Tolerable Average Residue Level, a possible risk for human health must be considered.

Factors influencing organotin distribution in different marine environmental compartments, and their potential health risk

Tributyltin (TBT) and triphenyltin (TPT) in different marine environmental compartments such as seawater, sediments, and inshore fishes were investigated in 21 Taiwanese harbors between 2001 and 2004 in order to determine the major factors influencing their distribution. The existence of major input sources and the limited water exchange rate inside the harbors were indicated by higher TBT concentrations in seawater from inner harbor than from outer harbor areas. The levels of TBT in sediments were found to be mainly affected by their geographic distribution, water exchange rates and shipping activity. No significant correlations in TBT concentrations between water, sediment and fish suggested TBT accumulation by fish might not result from water and sediment, but from their food. TPT were detected in most fish samples, but found in few sediment samples and none in seawater, indicating fish could be as a target element for monitoring contaminated levels of TPT in the aquatic environment. Mean concentrations of TBT in fish muscle higher than tolerable average residue levels (TARLs), and mean hazard indices of TBT and TPT higher than 1 suggested consumption of fishes from Taiwanese harbor areas might have potential high risk to human health.

Concentrations of organotin compounds in sediment and clams collected from coastal areas in Vietnam

Levels of butyltin (BT) and phenyltin (PT) compounds were determined in sediments and clam Meretrix spp. collected from north and central coastal areas in Vietnam. Concentrations of TBT in sediments ranged from 0.89 to 34 ng g −1 dry wt and those in clams ranged from 1.4 to 56 ng g −1 wet wt. The levels of TBT in sediments and clams from Vietnam were within limits reported from other countries. Further, the TBT level in clams was lower than the tolerable average residue level (TARL) estimated based on tolerable daily intake (TDI). Trace amounts of PTs were also found in both sediment and clam samples. In sediments from north and central Vietnam, the concentrations of TBT were highest in the order of Hue (28 ng g −1 dry wt), Cua Luc (15 ng g −1 dry wt), Sam Son (6.3 ng g −1 dry wt), and Tra Co (5.5 ng g −1 dry wt). Among the clams from north and central Vietnam, the levels of TBT in clams from Cua Luc were dramatically high at 47 ng g −1 wet wt. TBT formed the principal butyltin species in sediment at all sites studied. The ratios of TBT in sediment were higher among BT compounds at all study sites. Of total BTs, TBT was the dominant species in clams from almost all sites studied. In spatial distribution, TPT showed a pattern similar to TBT, suggesting the use of TPT as an antifouling paint. The partition coefficient between sediment and calms was calculated. The partition coefficients of TBT and TPT were 2.01 (0.56–5.5) and 9.23 (3.1–20), respectively. These results show that sediment-bound TBT is a source of contamination to clams in addition to dissolved TBT.

Asia‐Pacific mussel watch: Monitoring of butyltin contamination in coastal waters of Asian developing countries

Butyltin compounds (BTs) including mono-, di-, and tributyltin and total tin (sigmaSn), were determined in green mussels (Perna viridis) from various Asian developing countries, such as Cambodia, China (Hong Kong and southern China), Malaysia, India, Indonesia, the Philippines, and Vietnam, to elucidate the contamination status, distribution, and possible sources and to assess the risks on aquatic organisms and humans. Butyltin compounds were detected in green mussels collected from all the sampling location investigated, suggesting widespread contamination of BTs along the coastal waters of Asian developing countries. Among butyltin derivatives, tributyltin (TBT) was the predominant compound, indicating its ongoing usage and recent exposures in Asian coastal waters. Higher concentrations of BTs were found in mussels collected at locations with intensive maritime activities, implying that the usage of TBT as a biocide in antifouling paints was a major source of BTs. In addition, relatively high concentrations of BTs were observed in mussels from aquaculture areas in Hong Kong and Malaysia, as it has been reported in Thailand. With the recent improvement in economic status in Asia, it is probable that an increase in TBT usage will occur in aquaculture. Although contamination levels were generally low in mussel samples from most of the Asian developing countries, some of those from polluted areas in Hong Kong, India, Malaysia, the Philippines, and Thailand revealed levels comparable to those in developed nations. Furthermore, the concentrations of TBT in some mussels from polluted areas exceeded the threshold for toxic effects on organisms and estimated tolerable average residue levels as seafoods for human consumption. A significant correlation was observed between the concentrations of sigmaBTs and sigmaSn in mussels, and sigmaBTs were made up mostly 100% of sigmaSn in mussels taken from locations having intensive maritime/human activities. This suggests that anthropogenic BTs represent the major source of tin accumulation in mussels. To our knowledge, this is a first comprehensive report on butyltin pollution monitoring in developing countries in the Asia-Pacific region.

Butyltins in sediments and biota from the Pearl River Delta, South China

Butyltins in sediments and biota collected from the Pearl River Delta, South China were analyzed by a gas chromatograph–atomic emission detector (GC-AED). The concentrations of tributyltin (TBT) in the sediments ranged from 1.7 to 379.7 ng/g dry weight. Their spatial distribution suggested that shipping activities, especially shipyards were mostly responsible for the TBT contamination in the region. A good linear relationship was observed between the DBT (dibutyltin)/TBT and MBT (monobutyltin) /TBT ratios of the samples in the Pearl River, the Pearl River estuary and the West River, suggesting that TBT in these areas came from similar sources but had undergone a different extent of degradation. The butyltins in the Macao waters seemed to have undergone a different degradation process. All TBT concentrations of the fish, mussel and shrimp samples collected in this study were below the seafood tolerable average residue level (TARL).

Organotin Levels in Seafood

Tolerable average residue levels (TARL) for tributylin (TBT) in seafood products were calculated based on the tolerable daily intake (TDI) of TBT and the seafood consumption of the average consumer in various countries. Data from the literature show that these TARLs in seafood are exceeded in one or more samples in nine of the 22 countries for which data were available, i.e. Canada, France, Italy, Japan, Korea, Poland, Taiwan, Thailand and USA. In Italy also the average TBT residue level in seafood exceeded the TARL with a factor of 2.5, while in Japan the average TBT residue level in seafood almost equaled the TARL for this country. For the majority of countries, however, no data on organotin levels in seafood were available. This study shows that there is a need for country-specific maximum residue limits (MRL) for TBT in seafood products and that TBT levels in seafood should be monitored more regularly.