Organotin Concentrations Research Articles

An alternative silicone-based passive sampling device to derive organotin concentrations in the aqueous phase

Organotin compounds (OTs) are well studied in various environmental compartments, with a critical focus on the water column as their primary entry point into aquatic ecosystems. In this context, a method for the analysis of organotin (OTs) in water using silicone rubber-based passive sampling was optimized, validated, and field-tested. Validation covered crucial parameters, including the limit of detection (LOD), limit of quantification (LOQ), accuracy, precision, linearity, and matrix effect. The method was shown to be robust (R2 ≥ 0.99), with recoveries between 70.2 and 114.6%, and precise (CV < 12.8%) (N = 3). LODCw and LOQCw were ≤15 and ≤ 48 pg Sn L−1, respectively, for TBT and TPhT. The matrix effect showed to be low (>-20% ME < 20%) for all OTs but TPhT (69.4%). The silicone rubber–water partition coefficients (Log Ksr,w) were estimated at 3.37 for MBT, 3.77 for DBT, 4.17 for TBT, 3.49 for MPhT, 3.83 for DPhT, and 4.22 for TPhT. During the field study carried out between October 2021 and February 2022 at the entrance of the Port of Santos navigation channel (Southeastern Brazil), sampling rates ranged between 4.1 and 4.6 L d−1, and the equilibrium was achieved for MBT, DBT, MPhT, and DPhT after ∼45 days of deployment. The freely dissolved concentrations varied between 134 and 165 pg Sn L−1 for TBT, 388 and 610 pg Sn L−1 for DBT, and 1114 and 1509 pg Sn L−1 for MBT, while MPhT, DPhT, and TPhT were below the limit of detection. Results pointed out that J-FLEX® rubber-based passive sampling is a suitable and reliable alternative method for the continuous monitoring of OTs in the water column.

Occurrence of organotin compounds in food: increasing challenge of phenyltin compounds

Concentrations and distribution for 16 organotin compounds were studied in all kinds of foods, including seafood, agricultural products, and wine. Meanwhile, the degradation of the TBT or TPhT was also evaluated. Concentrations of total organotins in seafood, agricultural products, and wine were 1047.2, 469.4, and 13.5 μg Sn/kg. Meanwhile, the most frequently detected organotin in three kinds of samples were TPhT, MPhT, and MPhT, respectively. The results demonstrated that phenyltin may probably become an emerging organotin pollutant. Regarding seafood, organotin concentrations of fish and mollusks were much higher than those of crustaceans. At the same time, a significant positive correlation was observed between the concentrations of TBT and MBT (p < 0.05), and between DBT and MBT(p < 0.0001). Moreover, TPhT was significantly and positively associated with DPhT (p < 0.0001), suggesting that TPhT was the precursor of DPhT. Apart from the likely illegal use of OTs as biocides in antifouling paints for ships, anthropogenic activity like agricultural activity or industrial activity also caused organotin contamination. Further research and more effective measures should be formulated to protect the food safety. Meanwhile, monitoring of the organotin contamination should not only in Qinhuangdao, but also expand to the cities along Bohai Bay.

Bioaccumulation of antifouling biocides in mangroves and seagrasses in coastal ecosystems

Abstract We measured the concentrations of antifouling biocides in sediment, mangrove leaves and seagrasses from Merambong and Tinggi Island, Johor, Malaysia to evaluate their contamination levels. Although the concentrations of tributyltin (TBT) in mangrove leaves in Merambong in 2013 were significantly lower than those in 2012, the Sea-Nine 211 concentration in 2013 was significantly higher than that in 2012, suggesting that the use of antifouling biocides changed from TBT to Sea-Nine 211. The concentration of each BT (butyltin) and PT (phenyltin) in the mangrove area was significantly higher than the corresponding concentration in the seagrass area in Merambong, but the concentrations of Sea-Nine 211, diuron, chlorothalonil, Irgarol 1051 and M1 in seagrasses were significantly higher than those in mangrove leaves. There were differences in the accumulation profiles of OTs (organotins) and alternative biocides between the seagrass shoots and roots. The concentration of OTs in the seagrass roots was almost the same or higher than those in the shoots, whereas those of alternative biocides shows the opposite pattern to the OTs. Significant high relationships were observed between stable carbon isotope (δ13C) and OTs, Sea-Nine 211 and Irgarols in mangrove leaves. The concentrations of these compounds increased along with the δ13C values of the mangroves. These results suggest that mangroves take up the bicarbonate ions and nutrients in sediment and/or seawater through their roots, along with OTs, Sea-Nine 211 and Irgarols which were accumulated in sediment.

Concentrations of organotin compounds in aquatic biota in coastal waters of Johor, Malaysia

AbstractThe concentrations of organotin (OT) compounds, butyltin (BT) and phenyltin (PT), in aquatic organisms from Merambong and Tinggi Island, Malaysia, which differ in industrial and economic activities, were measured. Tributyltin (TBT) compounds among BTs ranged from 2.9–28 and &lt;0.1–21 ng g−1 ww in aquatic organisms from Merambong and Tinggi Island, respectively. Triphenyltin (TPT) compounds among PTs ranged from &lt;0.1–25 ng g−1 ww and &lt;0.1–61 ng g−1 ww in aquatic organisms from Merambong and Tinggi Island, respectively. A survey of OT concentrations among the species of OT compounds revealed that the concentrations of BTs and PTs in crabs and clams were high while those in fish were low. Correlation analysis with stable nitrogen isotopes suggest that OT compounds did not accumulate in aquatic organisms through the food web. The measurement of OT compounds in tissues and organs of fish revealed that BT concentrations in liver were higher than those in muscle and that BTs were detected in eggs of fish.

Organotin contamination in seafood from the Yucatán Peninsula, Mexico: Is there a potential risk for the health of consumers?

Since seafood is considered an important source of organotin compounds (OTCs), the present study assessed the potential risk to human health of ingesting butyltins (BTs) and phenyltins (PhTs) along with this type of food. Seafood samples were collected at five fishing sites in the Yucatán Peninsula (Mexico) during February and March 2018. In general, organotins were detected in all samples, suggesting a widespread occurrence of these compounds in the investigated region. The average concentration of total organotins in the muscle of demersal fish (Lutjanus synagris, Lutjanus campechanus, Calamus pennatula, Haemulon plumierii, Rhomboplites aurorubens), pelagic fish (Euthynnus alletteratus, and Opisthonema oglinum), gastropods (Melongena bispinosa and Strombus pugilis), oyster (Crassostrea virginica) and shrimp (Penaeus duorarum) was 146.7 ± 76.2, 93.1 ± 92.6, 61.0 ± 53.0, 76.7 ± 2.6, and 28.8 ± 2.7 ng Sn g−1 dry weight, respectively. Overall, MPhT among PhTs was the dominant compound in fish, while TBT among BTs was the dominant compound in shellfish. Regarding the toxic OTCs, TBT followed by DBT were the predominant compounds in all seafood species, while TPhT was below the quantification limit in most samples. The estimated daily intake values were lower than the tolerable daily intake (TDI) for the sum of organotins established by the European Food Safety Authority (EFSA). Furthermore, the hazard quotients (HQ) and hazard indices (HI) values were all lower than 1, suggesting that daily exposure to these levels of organotins is unlikely to cause any harm to the human health of seafood consumers at the Yucatán Peninsula. Thus, consumers may not be at risk through the inclusion of these investigated seafood species in their normal diet. However, due to the increasing coastal urbanization, maritime activities, and the likely illegal use of tin-based paints in Mexico, additional monitoring is needed to assess organotin levels in other regions along the Mexican coastal zone and using other seafood species.

Pulsed distribution of organotins in the turbidity maximum zone of the Yangtze Estuary throughout a tidal cycle

This study investigated the concentration fluctuation of organotin compounds in the Turbidity Maximum Zone (TMZ) of the Yangtze Estuary within a tidal cycle. Organotin concentrations varied greatly during the tidal cycle with dissolved organotins ranged from 39 to 682 ng Sn·L−1 and 40–1588 ng Sn·L−1, and particulate organotins ranged from 59 to 467 ng Sn·g−1 dw and 21–429 ng Sn·g−1 dw in TMZ water close to Hengsha Island and Jiuduansha Island, respectively. Meanwhile, the maximum levels of organotins appeared at each period of tidal transition, suggesting the tidal-driven pulsed exposure of organotins was prevalent in the estuaries. Besides, the organic carbon-normalized partition coefficients (Koc) of tri-organotins between suspended particulate matter (SPM) and aqueous phase were correlated with the phase distribution of natural organic matter (NOM). The dissolved tri-organotins were also associated with the properties of dissolved organic carbon (DOC) including aromaticity, hydrophobicity, and chromophoricity. Hence, pulsed exposure on organotins in the TMZ are highly dictated by the dynamic environmental conditions (i.e., SPM and NOM) with the tidal currents, which could further provide information to assess organotin ecological risks accurately in estuaries.

The first observation of antifouling organotin compounds and booster biocides in sediments from Samsun Port area, Black Sea, Turkey

The distribution of antifouling organotin compounds (OTCs) and booster biocides in surface sediments of Samsun Port (Black Sea, Turkey) in September 2014 was investigated by gas chromatography-tandem mass spectrometry (GC–MS/MS) method. The total organotin concentrations ranged from <1.0 to 669.6 ng/g, dw. Among the studied booster biocides, Diuron (<1.0–11.28 ng/g) was found in 70.58% of the investigated sediments, while Irgarol (<1.0–26.53 ng/g) was detected in two stations. Traces of fresh input organotin and high Irgarol were found at the park/repairment points of the port. The Principal Component Analysis (PCA) showed that sediment characteristic types and Total Organic Carbon (TOC) were the main relevant parameters in the accumulation of antifouling contamination in the Port area. In comparison with several types of environmental sediment quality criteria, Samsun Port is highly polluted area. The concentrations of OTCs and Diuron maybe used as a baseline reference level for future monitoring programs in Turkish Ports.

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.

Should TBT continue to be considered an issue in dredging port areas? A brief review of the global evidence

Dredging is periodically required to keep channels and maneuvering basins open in many ports around the world. However, the dredging of contaminated sediments may turn this routine procedure into a source of pollution in the receiving water bodies. Many pollutants, such as heavy metals, organic or organometallic compounds are present in high concentrations due to human activities in the coastal areas, where ports are located. Thus, the risks posed by dredging should be carefully evaluated for the conservation of environmental quality. Organotin compounds were extensively used as antifouling biocides worldwide for decades, causing considerable damage to localized coastal areas before being banned by IMO in 2008. Afterward, organotin concentrations decreased in most studied areas, as indicated by several recent studies in the literature. In some instances, however, there are still instances of biological effects of organotins application or legacy pollution being reported. It could be argued that until a complete recovery could be inferred, these “hot spots” should have organotins included in the evaluation of possible environmental impacts of dredging activities. Besides, when considering naval activities, most currently used antifouling systems still included biocides. The possible risks posed by these alternative technologies should be evaluated in the same way. This article briefly reviews this argument, using the recent literature on this subject.

Study of passive sampler calibration (Chemcatcher®) for environmental monitoring of organotin compounds: Matrix effect, concentration levels and laboratory vs in situ calibration

Application of Chemcatcher® to monitor organotin compounds [monobutyltin (MBT), dibutyltin (DBT) and tributlytin (TBT)] in sea water has been little developed. Prior to the measurement of the time-weighted average water concentrations (TWAC), a calibration step is required to determine sampling rates (Rs) which is usually assessed in a flow-through laboratory pilot where experimental conditions are well controlled. This paper investigates the effect of the water matrix (tap water vs real sea water from the harbor of Port Camargue in France) and organotin concentrations on the uptake rates of organotin compounds. Laboratory calibrations provided sampling rates in the range of 66–225 mL.day−1 in high concentration (usually used for laboratory calibrations) and in the range of 30–56 mL.day−1 at low concentrations (environmental range). When the tank is filled with real sea water, sampling rates were found to be in the range of 38–177 mL.day−1. In order to demonstrate the efficiency of Chemcatcher® in real conditions, in situ calibration was done in the harbor of Port Camargue. This calibration has been done in order to replicate environmental conditions: compounds concentrations, hydrodynamic and water matrix effects. To compare the impact of calibration procedures on TWAC determination, Chemcatcher® was deployed in the harbor of Port Camargue and spot sampling was performed to monitor the concentrations of organotins in water throughout the exposure period. Results obtained using the field Rs determined by in situ calibration were more reliable. In this case, TWAC is in agreement with spot sampling concentration.

A review of organotin contamination in arctic and subarctic regions

Abstract Organotin (OT) compounds are of continued Arctic concern as they are still widely used despite the most well-studied OT, tributyl tin (TBT), being restricted from use on marine vessels to prevent fouling by marine organisms. The highest OT concentrations found in Arctic fauna are in regions associated with human activity especially shipping. There is an overall trend of declining butyl tin (BT) concentrations in Arctic fauna especially molluscs which are the subject of a limited number of long-term monitoring studies. The incidence of imposex has likewise generally declined in molluscs in response to declining TBT concentrations. There are a number of knowledge gaps in OT occurrence and transport in the Arctic that warrant continued monitoring. OTs, in particular octyl tins, are heavily used in the production of plastic, hence leaching from plastic may be an unrecognized source to Arctic regions. This review also found several studies reporting volatile tin species in the atmosphere suggesting atmospheric transport of volatile tins to the Arctic is possible. Relative to other more well know persistent organic pollutants, there are few reports of OTs in marine mammals and temporal tend studies are needed to define trends in BTs and search for the occurrence of other tin species.

Organotin contamination in commercial and wild oysters from China: Increasing occurrence of triphenyltin

Organotin contamination in marine environment has been a public concern for many years due to its adverse impacts on biota and human health. This study investigated levels, distribution and health risks of six organotin compounds: tributyltin (TBT), dibutyltin (DBT), monobutyltin (MBT), triphenyltin (TPhT), diphenyltin (DPhT) and monophenyltin (MPhT) in commercial and wild oysters in China. The total organotin in commercial oysters ranged from 251 to 1949 ng Sn g−1 dw (dry weight) >. Two endocrine disruptors TBT and TPhT were detected in these samples with the highest level of 68.1 ± 20.1 ng Sn g−1 dw and 747 ± 7.3 ng Sn g−1 dw, respectively. For wild oysters, the concentrations of total organotins varied from 33.3 to 2671 ng Sn g−1 dw. Butyltins were dominated by TBT with the mean level of 26.1 ± 30.0 ng Sn·g−1 dw and showed no significant spatial variation between the southern and northern coastal zones (p > 0.05). However, compared with the north, phenyltin levels especially TPhT were much higher in the south coastline (246–1484 ng Sn·g−1 dw) due to the wider use of TPhT-based biocides in local mariculture and agriculture. Health risk assessment indicated that a daily exposure of TPhT-contaminated oysters (including commercial and wild ones) may pose adverse threats to human particularly children as the risk quotients (RQ) were higher than 1. Organotin contamination (e.g., TPhT) still occurs in the South China's coastal zones after the TBT ban, which deserves future research and effective measures to protect the marine ecosystem and human health.

Occurrence and health risk assessment of organotins in waterworks and the source water of the Three Gorges Reservoir Region, China.

The occurrence and health risks of organotins (OTs) in the waterworks and source water in the Three Gorges Reservoir Region (TGRR), China were assessed in this study. Water samples were collected at four waterworks (A, B, C, and D) in March and July 2012 to analyze butyltins (BTs) and phenyltins (PTs) using a gas chromatography-mass spectrometry (GC-MS) system. Our results showed that both the waterworks and their nearby water sources were polluted by OTs, with PTs being the most dominant species. Monobutyltin (MBT), monophenyltin (MPT), diphenyltin (DPT), and triphenyltin (TPT) were detected in most of the analyzed water samples. The highest concentrations of OTs in influents, effluents, and source water in March were 52.81, 17.93, and 55.32ngSnL-1, respectively. Furthermore, significant seasonal changes in OTs pollution were observed in all samples, showing pollution worse in spring compared with summer. The removal of OTs by the conventional treatment processes was not stable among the waterworks. The removal efficiency of OTs in July reached 100% at plant B, while that at plant C was only 38.8%. The source water and influents shared similar composition profiles, concentrations, and seasonal change of OTs, which indicated that OTs in the waterworks were derived from the source water. A health risk assessment indicated that the presence of OTs in the waterworks would not pose a significant health risk to the population, yet their presence should not be ignored.

Distribution and accumulation of persistent organic pollutants in aquatic organisms of Chinese lakes

持久性有机污染物（POPs）在环境中分布广泛且持久存在并具有高生物富集性，通常具有致癌、致畸、致突变等危害.湖泊是POPs的主要环境归宿之一，湖泊中的POPs可被水生生物富集并通过食物网传递，对生态系统及人体健康构成极大的危害.中国是POPs生产及使用大国，也是世界上湖泊较多的国家之一.湖泊生物尤其是水产品是中国人饮食中的重要组成部分，因此POPs在中国湖泊生物体中的富集对当地的生态系统和人体健康存在很大的潜在危害.本文通过收集、分析1997年2017年7月公开发表的中国湖泊生物体POPs数据，发现中国湖泊生物中POPs富集研究主要集中在东部平原湖区，青藏高原及云贵高原湖区有少量研究；不同POPs在不同湖区湖泊生物中富集的含量存在较大差异，DDTs和HCHs在各湖区生物中普遍检出且存在明显差异，东部平原湖区生物体内多氯联苯、多溴联苯醚含量高于其他湖区生物体内含量，其他POPs在湖泊生物体内的富集研究相对较少且主要集中在东部湖泊.中国湖泊生物中DDTs、HCHs、多环芳烃、多氯联苯、多溴联苯醚、多氯苯并二噁英和多氯苯并呋喃、全氟化合物、全氟辛酸、有机锡及六溴环十二烷脂肪归一化后的平均含量分别为454.56±653.40、153.57±435.99、2849.49±3092.52、118.40±20.28、18.40±20.28、17.43±19.43、147.17±192.93、1542.18±1347.64、11380.75±5316.75和2.19±1.92 ng/g.POPs在中国湖泊生物体内的含量水平与生物所处营养级、脂肪含量和年龄呈正相关，但并非完全一致，还受到生活习性、生物物种与结构、生存环境及生物量等多种因素的影响；生物不同组织对POPs的富集能力有较大差异，内脏器官对POPs的富集能力明显高于肌肉组织.;Persistent organic pollutants (POPs) are usually carcinogenic, teratogenic, and mutagenic. They are widely and persistently present in the environment, and have high bioaccumulation ability by organisms. Lake is one of the main environmental sinks for POPs. POPs in lakes can be accumulated by aquatic organisms and transported through the food webs, which pose great risks to ecosystem and human health. China has the large usage and production of POPs, which also has large amount of lakes. Lake organisms, especially aquatic products, are important parts of the Chinese diet, thereby the enrichment of POPs in Chinese lakes and organisms poses great risks to the local ecosystems and human health. We collected and analyzed large amount of published data on POPs in organisms of Chinese lakes until July 2017. We found that previous studies on bioaccumulation of POPs in Chinese lakes mainly focused in the eastern plain lake area. There were only a few studies in the Qinghai-Tibet Plateau and Yunnan-Guizhou Plateau Lake area. The concentrations of different POPs varied greatly in different lake organisms. DDTs were widely detected with little difference in concentrations in organisms in the studied lakes. The concentrations of HCHs, PCBs; and PBDEs in organisms in the eastern lake area were significantly higher than those in other lake areas. Only a few studies focused on bioaccumulation of other POPs by organisms in lakes, and were mainly in the lakes in the eastern plain. The concentrations of DDTs, HCHs, PAHs, PCBs, PBDEs, PCDD/Fs, PFOSs, PFOAs, Organotins and PHBCDs were 454.56±653.40, 153.57±435.99, 2849.49±3092.52, 159.22±272.36, 18.40±20.28, 17.43±19.43, 147.17±192.93, 1542.18±1347.64 and 2.19±1.92 ng/g in organisms of Chinese lakes based on the lipid content. Bioaccumulation of POPs in lake organisms is generally positively related to the trophic level, lipid content and age of organisms, but it is not always true. It is also impacted by factors such as living habits, biological species and composition, living environment and biomass. Bioaccumulation of POPs was also different in different tissues. Bioaccumulation of POPs was higher in liver, gallbladder, heart and head than that in muscle tissues.

Occurrence of organotins in the aquatic environment during an operating cycle of the Three Gorges Reservoir, China.

Organotins (OTs) pollution in the aquatic environment of the Three Gorges Reservoir (TGR) was assessed during the reservoir's operating cycle. Butyltins (BTs) and phenyltins (PhTs) in the water phase and suspended particulate matter (SPM) at different water levels were analysed. It was found that the distribution of OTs in the surface and bottom water phases were similar, with the dominant OTs being BTs at the low water level and PhTs at the high water level. The detection rates and concentrations of OTs in the water phase at the high water level were both higher than those at the low water level, with most OTs being monobutyltin (MBT) at the low water level and monophenyltin (MPhT) at the high water level. The concentrations of OTs in SPM at the low water level were higher than those at the high water level, and BTs, especially dibutyltin (DBT) and tributyltin (TBT), were the predominant OTs whether surface or bottom layer at each water level. The BTs and SPM concentrations had a significant positive relationship in all samples, indicating that the SPM concentration would determine the distribution of BTs in the aquatic environment of the TGR region (TGRR). The difference in the distribution of OTs at the different water levels indicated that the hydrological and hydraulic behaviour of the TGR influences OTs transport in the aquatic environment of the TGRR.

Development and evaluation of a new diffusive gradients in thin-films technique for measuring organotin compounds in coastal sediment pore water

Organotins present a toxicological risk to biota in the aquatic environment. Understanding the behaviour of these compounds in sediment is challenging, with sophisticated analytical techniques required for their measurement. We investigated the use of silica-bound sorbents for diffusive gradients in thin-films (DGT) adsorption gels to pre-concentrate five organotins (monobutlytin (MBT), dibutyltin (DBT), tributyltin (TBT), diphenyltin (DPhT), triphenyltin (TPhT)) found frequently in coastal sediment. C8 sorbent showed optimum performance in uptake and recovery of organotins for pH and ionic strength ranges typical of coastal waters. Recoveries from adsorption gels deployed in filtered sea water were MBT = 123 ± 20%, DBT = 75 ± 12%, TBT = 81 ± 16%, DPhT = 72 ± 30%, TPhT = 58 ± 10% respectively. Devices were used to investigate DGT fluxes and pore water concentrations of organotins in coastal sediment collected from a contaminated site. DGT fluxes measured in sediment cores for the five organotins ranged between 4.3 × 10−8 and 1.6 ×10−5ngcm2s−1. The depletion of organotin species within pore waters at the interface with DGT devices was measured over a series of deployment times (2, 7, 14, 21 and 28 days) and provided estimates of the concentration of organotins in pore waters at Langstone Harbour, UK, prior to depletion by the DGT device and information on their spatial heterogeneity. The novel in situ DGT device developed can pre-concentrate organotins from pore waters in coastal sediment core samples and allows their detection at low environmental concentrations using conventional gas chromatographic/mass spectrometric instrumentation. Use of the DGT device overcomes many problems associated with the conventional pore water sampling of organotins. Our preliminary data suggests it has potential in the future to be a useful tool in investigating the environmental fate of these pollutants. The use of the C8 gel will also allow for the simultaneous sequestration of other semi- and non-polar analytes present in the pore water.

Biomonitoring of metals by aquatic mosses in a mining region

The aim of this work is to estimate background concentrations of organometallic compounds, such as tributyltin (TBT), dibutyltin (DBT), monobutyltin (MBT), triphenyltin (TPhT), diphenyltin (DPhT), monophenyltin (MPhT), methylmercury (MeHg), inorganic mercury (iHg) and diethyllead (Et2Pb) in the aquatic environment at the French national scale.Both water and sediment samples were collected all over the country, resulting in 152 water samples and 123 sediment samples collected at 181 sampling points. Three types of surface water bodies were investigated: rivers (140 sites), lakes (19 sites) and coastal water (42 sites), spread along the 11 French river basins. The choice of sites was made on the basis of previous investigation results and the following target criteria: reference, urban sites, agricultural and industrial areas. The analytical method was properly validated for both matrices prior to analysis, resulting in low limits of quantification (LOQ), good precision and linearity in agreement with the Water Framework Directive demands. The results were first evaluated as a function of their river basins, type of surrounding pressure and water bodies. Later, background concentrations at the French national scale were established for both water and sediment matrices, as well as their threshold, i.e., the concentration that distinguishes background from anomalies or contaminations. Background concentrations in water are ranging between <0.04–0.14 ng Hg. L−1 for MeHg, <0.14–2.10 ng Hg. L−1 for iHg, <1.0–8.43 ng Pb. L−1 for Et2Pb and 0.49–151 ng Sn. L−1, <0.08–3.04 ng Sn. L−1 and <0.08–0.25 ng Sn. L−1 for MBT, DBT and TBT, respectively. For sediments, background concentrations were set as <0.09–1.11 ng Hg. g−1 for MeHg, <0.06–24.3 ng Pb. g−1 for Et2Pb and <1.4–13.4 ng Sn. g−1, <0.82–8.54 ng Sn. g−1, <0.25–1.16 ng Sn. g−1 and <0.08–0.61 ng Sn. g−1 for MBT, DBT, TBT and DPhT, respectively. TBT occurs in higher concentrations than the available environmental protection values in 24 and 38 sampling sites for both water and sediment samples, respectively. Other phenyltins (MPhT and TPhT) did not occur above their LOQ and therefore no background was possible to establish. Throughout this work, which is the first assessment of background concentrations for organometallic compounds at the French national level ever being published, it was possible to conclude that over the last 10–20 years organotin concentrations in French river basins have decreased while MeHg concentration remained stable.

Imposex status associated with organotin contamination in Reishia clavigera after reciprocal transplantation between clean and polluted sites in Hong Kong

Recent biomonitoring studies have showed that contaminations of triphenyltin (TPT), relative to levels of tributyltin, have become more serious in Hong Kong and other South China coasts. However, there is a lack of field-based evidence to demonstrate the casual relationship between TPT and imposex development in the rock shell Reishia clavigera in this region. This study aimed to investigate the temporal changes of imposex development and tissue concentration of six organotins (OTs) in tissues of R. clavigera after their reciprocal transplantation between relatively clean and polluted sites in Hong Kong for six months. The results revealed a significant increase of tissue concentration of total OTs, in particular TPT, in the rock shells transplanted from a clean site to a polluted site, while a decrease of tissue OT concentrations was observed in those treated conversely. Vas Deferens Sequence Index, one of the imposex indices, only increased slightly for rock shells transplanted from clean to polluted sites, while Relative Penis Size Index elevated remarkably for the same treatments. In general, the rock shells had lower tissue concentrations of OTs in winter than that in summer, though the exact mechanism is still unknown. This study has further confirmed that OT contamination is still prevalent in Hong Kong’s coastal marine waters, which necessitates tightened management controls on this group of chemicals especially on TPT compounds.

Imposex and organotin compounds in ports of the Mediterranean and the Atlantic: Is the story over?

Organotin compounds are toxic substances released into the marine environment from antifouling paints. Sixty-two years following their first application and 9years after the complete ban on their use as biocides in 2003 (EC No. 782/2003), their negative impact on mollusks was still evident, as illustrated by imposex (i.e. the masculinization of female gastropods). This phenomenon is widely used to investigate tributyltin (TBT) pollution, with Hexaplex trunculus and Nassarius nitidus being considered as sensitive bioindicators. H. trunculus specimens and sediment samples collected from the ports of Cagliari (Sardinia), El Kantaoui (Tunisia) and Olhão (Portugal), along with N. nitidus individuals from the port of Faro (Portugal), were used for the assessment of imposex intensity and organotin pollution in these areas. High imposex frequency and organotin concentrations (TBT, triphenyltin (TPhT) and their degradation products) were observed, especially in Sardinia, implying that these chemicals remain a significant pollution issue in the specific Mediterranean ports. Moreover, the highly significant relationship established between penis length of imposex-affected females H. trunculus and TBT/TPhT concentrations offers a rapid and nonsacrificial proxy model for assessing the impact of organotins in coastal environments. Finally, the complementary use of more than one TBT bioindicator is advised in order to obtain more accurate results in detailed monitoring studies of TBT pollution.

Long-Term Spatio-Temporal Trends of Organotin Contaminations in the Marine Environment of Hong Kong.

Hong Kong imposed a partial restriction on application of organotin-based antifouling paints in 1992. Since September 2008, the International Maritime Organization prohibited the use of such antifouling systems on all sea-going vessels globally. Therefore, it is anticipated a gradual reduction of organotin contamination in Hong Kong’s marine waters. Using the rock shell Reishia clavigera as a biomonitor, we evaluated the organotin contamination along Hong Kong’s coastal waters over the past two decades (1990–2015). In 2010 and 2015, adult R. clavigera were examined for imposex status and analysed for tissue concentrations of six organotins. We consistently found 100% imposex incidence in female R. clavigera across all sites. Tissue triphenyltin (TPT) concentrations were high in most samples. A probabilistic risk assessment showed that there were over 69% of chance that local R. clavigera would be at risk due to exposure to phenyltins. Comparing with those of previous surveys (2004–2010), both imposex levels and tissue concentrations of organotins did not decline, while the ecological risks due to exposure to organotins were increasing. We also observed high concentrations of monobutyltin and TPT in seawater and sediment from locations with intense shipping activities and from stormwater or sewage discharge. Overall, organotins are still prevalent in Hong Kong’s marine waters showing that the global convention alone may be inadequate in reducing organotin contamination in a busy international port like Hong Kong. Appropriate management actions should be taken to control the use and release of organotins in Hong Kong and South China.