Metal concentrations in transitional and coastal waters measured by passive (Diffusive Gradients in Thin-films) and spot sampling: MONITOOL Project Dataset

The MONITOOL project (2017-2023) was carried out to describe the relationships between total dissolved and labile metal concentrations measured in spot water samples and in concurrently deployed Diffusive Gradients in Thin-films (DGTs) passive samplers, respectively. The ultimate aim was to adapt existing marine metal Environmental Quality Standards (EQS marine water) for DGTs, enabling their use in the context of the European Directives (the Water Framework Directive (WFD) and the Marine Strategy Framework Directive (MSFD)). Time-integrated metal concentrations provided by DGTs, representing several days, are an advantage compared to conventional spot sampling, especially in highly dynamic systems, such as transitional waters. Hence, the MONITOOL project aimed to provide a robust database of dissolved and labile metal concentrations in transitional and coastal waters, based upon co-deployments of DGTs and collection of spot water samples at several sampling sites (England, France, Ireland, Italy, Northern Ireland, Portugal, Scotland and Spain), followed subsequently by DGT and water metal analysis. Samplings were carried out in 2018 and 2022, following agreed protocols developed in the framework of the project. The MONITOOL dataset includes metal concentrations from DGTs, measured with Inductively Coupled Plasma Mass Spectrometry (ICP-MS: Cd, Co, Cu, Fe, Mn, Ni, Pb, Zn) and in concurrently collected spot water samples by ICP-MS (Al, Cd, Co, Cu, Mn, Ni, Pb, Zn) and Anodic/Cathodic Stripping Voltammetry (ASV/CSV: Cd, Pb, Ni). Moreover, data on seawater physical-chemical parameters (salinity, temperature, dissolved oxygen, pH, turbidity, total suspended solids, dissolved organic carbon, and total organic carbon) is provided. This database presents the results obtained using, concurrently, different forms of sampling and analytical techniques, enabling the comparison of the results obtained by these strategies and allowing the adaptation of EQS in marine water (EQS marine water) to DGTs (EQS DGT), in the context of the WFD. Moreover, due to the large number of sampling sites, it could also be used for other types of research, such as those dealing with metal speciation or the determination of baseline levels.

PAHs and trace metals in marine surficial sediments from the Porcupine Bank (NE Atlantic): A contribution to establishing background concentrations

Little is known about pollutant concentrations in marine remote areas such as the Porcupine Bank in the NE Atlantic Ocean. Remote locations are much less studied than the more readily accessible coastal areas, nevertheless, are of great importance both to unveil how far human influence has reached and, are more challenging, to infer background concentrations (BCs) of naturally occurring and/or anthropogenic pollutants. Knowledge of contaminant background levels are critical for establishing remediation and management strategies; in addition, background assessment is heavily emphasised in legislative monitoring requirements. Obtaining suitable sampling locations to assess background concentrations can be challenging, as samples should match characteristics to the target area and not be impacted by historical or current inputs of the chemical substances of study. Anthropogenic impacts generally deem local-based sampling to be unsuitable to infer background pollution values. Sampling in remote areas such as the Porcupine Bank better fulfils low impact and pressure requirements making them more suitable for the derivation of background concentration estimates for organic compounds and metals. The total concentrations of polycyclic aromatic hydrocarbons (PAHs) and metal(loid)s in deep sea sediments were evaluated and both an environmental status and a set of concentration data were adequate to derive BCs concentrations is presented. Concentration data indicated, in comparison with previous published data, trace level presence of PAHs and metal(loids) in sediments from the Porcupine Bank. These values will provide a valuable tool to identify the natural presence of organic and inorganic compounds and be the basis to perform a sound environmental assessment.

Development and application of an LC-MS method to the determination of poly- and perfluoroalkyl substances (PFASs) in drinking, sea and surface water samples

Poly- and perfluoroalkyl substances (PFASs) are a group of synthetic organic surfactants that have become a global concern because of their toxicity and widespread presence in the aquatic environment and organisms globally. In this study, a new analytical method has been developed and validated for the analysis of 15 perfluorinated compounds in different water matrices: river water, drinking water and seawater. Water extraction was performed in anion exchange solid phase extraction cartridges, and extracts were analysed by liquid chromatography in tandem with mass spectrometry. Recoveries for target analytes were between 35 and 120%, depending on the water matrix. Method detection limits were in the range of 0.5-17 ng L^-1. The validated method was applied to the determination of perfluorinated compounds in water samples around Ireland. Eight compounds out of fifteen were detected at least in one sample. Measured concentrations were higher in river water than seawater, and drinking water had the lowest levels, although still detectable for a considerable amount of compounds. The most prevalent compounds were PFPeA, PFOA and PFHxA, present in all types of water, and they had the highest concentrations.

Metals concentrations in transitional and coastal waters by ICPMS and voltammetry analysis of spot samples and passive samplers (DGT)

This study investigates the relationships among Ni, Cd and Pb's different chemical forms determined by different methodologies in coastal and transitional waters across a broad geographical scale. Concentrations were measured in spot samples and through passive sampling (DGT). High variability of metal concentrations was found among sampling sites and methodologies due to natural water fluctuations rather than to a given metal or method. Total dissolved metal concentrations in spot samples were lower than the EQS-WFD values. The labile fractions of Cd and Pb, measured in spot samples by Anodic Stripping Voltammetry and by DGT-ICPMS, were highly correlated. Similar labilities were found for Cd, while for Pb, the ASV labile fraction was ≈50% lower. These results reflect the pool of mobile and labile species available towards each technique kinetic window, and they seem not to be affected by discrete sampling flaws.

Legacy and emerging contaminants in common guillemot Uria aalge eggs in Ireland and Wales

Guillemot eggs from multiple Irish colonies and one Welsh colony were analysed for legacy pollutants such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and other organochlorine compounds (OCs), as well as metals. Stable isotope ratios of carbon (δ¹³C) and nitrogen (δ¹⁵N) were measured in eggs to understand the influence of diet on contaminant levels detected. Wide-scope target and suspect screening techniques were used on a single guillemot egg, providing novel information on contaminants of emerging concern. Stable isotope ratio analysis showed that guillemots from Great Saltee Island and Lambay Island (Ireland's east coast) had a similar carbon source (δ¹³C) and fed at similar trophic levels (δ¹⁵N), pollutant levels were higher in eggs from Lambay Island near Dublin, Ireland's industrialised capital city. Guillemot eggs from Aughris Head (Atlantic west coast of Ireland), and Skomer Island (Wales) had differing isotopic niches to other colonies. Egg samples from Aughris Head had the lowest levels of pollutants in this study (with the exception of mercury) and amongst the lowest levels reported worldwide. In contrast, Skomer Island had the highest level of pollutants with higher concentrations of Σ16PCB, Σ6PBDE and HCB than Irish colonies, most likely a result of its proximity to historically industrial areas. Levels of PCBs, p,p' -DDE and mercury in guillemot eggs have decreased over time according to this study, in concurrence with worldwide trends. Levels of pollutants in guillemot eggs, in this study, fall below existing thresholds for adverse effects in other species, with the exception of mercury.

Polycyclic aromatic hydrocarbons (PAHs) in seabird eggs in Ireland

Seabird eggs are considered a favourable matrix for monitoring marine pollutants and are widely used as higher trophic level indicators. Concentrations of Polycyclic aromatic hydrocarbons (Σ15PAH) were determined in the eggs of four piscivorous seabirds in Ireland from multiple colonies for the first time, Common Guillemot Uria aalge, Northern Gannet Morus bassanus, Common Tern Sterna hirundo and Arctic Tern S. paradisaea. PAH concentrations were generally lower than levels detected in eggs from other seabird studies and considerably lower than concentrations associated with no adverse effect in the eggs of domestic avian species. This study indicates potential site and species differences in PAH concentrations. Baseline data of PAHs in a range of seabird species from this study may provide an important reference point should a major pollution event occur in European waters, such as an oil spill.

Concurrent sampling of transitional and coastal waters by Diffusive Gradient in Thin-films (DGT) and spot sampling for trace metals analysis

This protocol was developed based on the knowledge acquired in the framework of the Interreg MONITOOL project (EAPA_565/2016) where extensive sampling campaigns were performed in transitional and coastal waters covering eight European countries. It provides detailed procedures and guidelines for the sampling of these waterbodies by concurrent collection of discrete water samples and the deployment of Diffusive Gradient in Thin-films (DGT) passive samplers for the measurement of trace metal concentrations. In order to facilitate the application of this protocol by end-users, it presents steps to follow in the laboratory prior to sampling campaigns, explains the procedures for field campaigns (including in situ measurement of supporting parameters) and subsequent sample processing in the laboratory in preparation for trace metal analyze by inductively coupled plasma-mass spectrometry (ICP-MS) and voltammetry. The protocol provides a systematic, coherent field sampling and sample preparation strategy that was developed in order to ensure comparability and reproducibility of the data obtained from each project Partner in different regions. • Standardization of the concurrent sampling of transitional and coastal waters by DGT passive samplers and spot sampling. • Robust procedures and tips based on existing international standards and comprehensive practical experience. • Links to demonstration videos produced within the MONITOOL project.

Assessing variability in the ratio of metal concentrations measured by DGT-type passive samplers and spot sampling in European seawaters

The current study evaluates the effect of seawater physico-chemical characteristics on the relationship between the concentration of metals measured by Diffusive Gradients in Thin films (DGT) passive samplers (i.e., DGT-labile concentration) and the concentrations measured in discrete water samples. Accordingly, Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used to measure the total dissolved metal concentrations in the discrete water samples and the labile metal concentrations obtained by DGT samplers; additionally, lead and cadmium conditional labile fractions were determined by Anodic Stripping Voltammetry (ASV) and total dissolved nickel was measured by Cathodic Stripping Voltammetry (CSV). It can be concluded that, in general, the median ratios of DGT/ICP and DGT/ASV(CSV) were lower than 1, except for Ni (median ratio close to 1) and Zn (higher than 1). This indicates the importance of speciation and time-integrated concentrations measured using passive sampling techniques, which is in line with the WFD suggestions for improving the chemical assessment of waterbodies. It is the variability in metal content in waters rather than environmental conditions to which the variability of the ratios can be attributed. The ratios were not significantly affected by the temperature, salinity, pH, oxygen, DOC or SPM, giving a great confidence for all the techniques used. Within a regulatory context such as the EU Water Framework Directive this is a great advantage, since the simplicity of not needing to use corrections to minimize the effects of environmental variables could help in implementing DGTs within monitoring networks.

Persistent pollutants in fresh and abandoned eggs of Common Tern (Sterna hirundo) and Arctic Tern (Sterna paradisaea) in Ireland

Higher levels of persistent pollutants (Σ16PCB, Σ6PBDE, ΣHCH, ΣDDT, ΣCHL) were detected in fresh eggs of Common Terns Sterna hirundo from Rockabill Island near Dublin (Ireland's industrialised capital city) compared to Common and Arctic Terns S. paradisaea from Ireland's west coast. Intra-clutch variation of pollutant levels in Common Terns was shown to be low, providing further evidence that random sampling of one egg may be an appropriate sampling strategy. Significant differences in pollutant concentrations were detected between fresh and abandoned eggs on Rockabill. However, abandoned eggs can still provide a useful approximation of pollutants in bird eggs if non-destructive sampling is preferred. Levels of p,p' -DDE in tern eggs have decreased over time according to this study, in concurrence with worldwide trends. Results in this study fall below toxicological thresholds for birds and OSPARs EcoQO thresholds set for Common Tern eggs, except for mercury and HCH in the west coast.

Persistent pollutants in Northern Gannet Morus bassanus eggs in Ireland: Levels and colony differences

Seabird eggs are considered a favourable matrix for monitoring marine pollutants and are widely used as higher trophic level indicators. Persistent organic pollutants such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and other organochlorine compounds (OCs) as well as metals have been shown to have deleterious impacts on seabirds. The Northern Gannet Morus bassanus is an avian sentinel; the largest breeding seabird in Ireland and an obligate piscivore. Gannet eggs were collected from two island colonies off the east coast of Ireland in locations with divergent history of industrialisation. Contaminant levels were measured and differences in concentrations between colonies compared. Stable isotope ratios of carbon (δ₁₃C) and nitrogen (δ₁₅N) were measured in each egg to understand the influence of diet and trophic position on contaminant levels detected. Significantly higher levels of Σ14PCBs, Σ7PBDEs and total mercury were detected in Gannet eggs from Lambay Island near Dublin (Ireland's industrialised capital city) compared to Great Saltee Island. No differences were observed in levels of other OCs (HCB, ΣHCH, ΣCHL, ΣDDT) between the two colonies. Though Gannets travel significant distances when foraging for food, tracking studies have demonstrated that birds from proximal breeding colonies maintain exclusive feeding areas. Stable isotope ratio analysis in this study demonstrated that Gannets at both locations occupy similar dietary niches, indicating that dietary differences may not be the driver of differing contaminant levels between colonies. Levels of persistent pollutants in the Gannet eggs fall below most existing thresholds for adverse effects and are within internationally reported values. Recent population growth and range expansion of Gannets in Ireland suggest that persistent pollutants are not having an immediate impact on the Gannet population. This study will inform potential monitoring programmes that can help Ireland achieve good environmental status under the European Union's Marine Strategy Framework Directive.

High concentrations of persistent organic pollutants in adult killer whales (Orcinus orca) and a foetus stranded in Ireland

Bio-accumulation of persistent organic pollutants including polychlorinated biphenyls (PCBs), brominated flame retardants and organochlorine pesticides continue to be of major concern for marine apex predators such as killer whales. The concentrations of 16 polychlorinated biphenyls, 7 poly-brominated diphenyl ethers (PBDEs), 1 poly-brominated biphenyl (PBB) and a range of 19 organochlorine compounds (OCs) was investigated in blubber samples from a mother-foetus pair, an adult female and an adult male killer whale stranded in Ireland between 2010 and 2017. Concentrations ranged from 1.5 mg/kg to 49.3 mg/kg lipid weight and 0.04-1.2 mg/kg lipid weight for Σ16PCBs and Σ7PBDEs respectively. Concentrations of organochlorine compounds were also investigated in the male killer whale; a Σ19OC concentration of 49.4 mg/kg lipid weight was recorded. This study shows high levels of persistent organic pollutants occur in this species of whales stranded in Ireland.

Passive sampling of polar emerging contaminants in Irish catchments

Passive sampling (PS) is a very useful approach for the monitoring of emerging contaminants in environmental matrices, showing greater sensitivity than can be achieved by current best practice - grab sampling - and is applicable to a wide variety of compounds. An EU Directive (2013/39/EC) has added substances to the existing Water Framework Directive (WFD) Priority Substance list. Investigation into PS in the monitoring of these compounds is necessary to show the potential of this technique in supporting monitoring requirements under the WFD. A catchment-based approach evaluated the occurrence of these compounds in Irish surface waters. This work deals with the challenges associated with the use of PS in a legislative context, and for routine monitoring of emerging contaminants. Looking at a number of sites across Ireland, upstream and downstream of wastewater treatment plants, the focus was on polar analytes and polar PS (POCIS). With method limits of detection (LODs) of 0.001 mg L^-1 pharmaceuticals and endocrine disrupting chemicals (EDCs) were found in water and passive samples alike, whereas the polar pesticides were not often detected or were below the annual average environmental quality standard levels. The results of this study show the potential for PS as a monitoring technique for emerging and watch-list chemicals.

Integration of biological effects, fish histopathology and contaminant measurements for the assessment of fish health: A pilot application in Irish marine waters

This study investigates the use of a weight of evidence (WOE) approach to evaluate fish health status and biological effects (BEs) of contaminants for assessment of ecosystem health and discusses its potential application in support of the Marine Strategy Framework Directive (MSFD). External fish disease, liver histopathology and several BEs of contaminant exposure including 7-ethoxy resorufin O-de-ethylase (EROD), acetylcholinesterase (AChE), bile metabolites, vitellogenin (VTG) and alkali labile phosphates (ALP) were measured in two flatfish species from four locations in Ireland. Contaminant levels in fish were generally low with PCBs in fish liver below OSPAR environmental assessment criteria (EAC). There were consistencies with low PCB levels, EROD and PAH bile metabolite levels detected in fish. Dab from Cork, Dublin and Shannon had the highest relative prevalence of liver lesions associated with the carcinogenic pathway. An integrated biomarker response (IBR) showed promise to be useful for evaluation of environmental risk, although more contaminant parameters in liver are required for a full assessment with the present study.

Monitoring, sources, receptors, and control measures for three European Union watch list substances of emerging concern in receiving waters - A 20year systematic review

Pollution of European receiving waters with contaminants of emerging concern (CECs), such as with 17-beta-estradiol (a natural estrogenic hormone, E2), along with pharmaceutically-active compounds diclofenac (an anti-inflammatory drug, DCL) and 17-alpha-ethynylestradiol (a synthetic estrogenic hormone, EE2)) is a ubiquitous phenomenon. These three CECs were added to the EU watch list of emerging substances to be monitoring in 2013, which was updated in 2015 to comprise 10 substances/groups of substances in the field of water policy. A systematic literature review was conducted of 3952 potentially relevant articles over period 1995 to 2015 that produced a new EU-wide database consisting of 1268 publications on DCL, E2 and EE2. European surface water concentrations of DCL are typically reported below the proposed annual average environmental quality standard (AA EQS) of 100ng/l, but that exceedances frequently occur. E2 and EE2 surface water concentrations are typically below 50ng/l and 10ng/l respectively, but these values greatly exceed the proposed AA EQS values for these compounds (0.04 and 0.035ng/l respectively). However, levels of these CECs are frequently reported to be disproportionately high in EU receiving waters, particularly in effluents at control points that require urgent attention. Overall it was found that DCL and EE2 enter European aquatic environment mainly following human consumption and excretion of therapeutic drugs, and by incomplete removal from influent at urban wastewater treatment plants (WWTPs). E2 is a natural hormone excreted by humans which also experiences incomplete removal during WWTPs treatment. Current conventional analytical chemistry methods are sufficiently sensitive for the detection and quantification of DCL but not for E2 and EE2, thus alternative, ultra-trace, time-integrated monitoring techniques such as passive sampling are needed to inform water quality for these estrogens. DCL appears resistant to conventional wastewater treatment while E2 and EE2 have high removal efficiencies that occur through biodegradation or sorption to organic matter. There is a pressing need to determine fate and behaviour of these CECs in European receiving waters such as using GIS-modelling of river basins as this will identify pressure points for informing priority decision making and alleviation strategies for upgrade of WWTPs and for hospital effluents with advanced treatment technologies. More monitoring data for these CECs in receiving waters is urgently needed for EU legislation and effective risk management.

Application of a weight of evidence approach utilising biological effects, histopathology and contaminant levels to assess the health and pollution status of Irish blue mussels (Mytilus edulis)

A weight of evidence (WOE) approach, integrating biological effects, mussel histopathology and tissue contaminant levels is proposed to evaluate mussel health and pollution status. Contaminant levels, histopathology and several biological effects (BEs) including Lysosomal membrane stability (LMS), acetylcholinesterase (AChe), metallothionein proteins (MT) and alkali labile phosphate (ALP), in Mytilus edulis are presented, improving the current knowledge base for these data. Potential links between histopathology, BEs and contaminants and ranking of sites are investigated with an integrated response (IR) indexing technique. Histopathological condition indices (Ih) in mussel digestive gland are used to calculate health indices. A spatial and temporal assessment is conducted at Irish coastal locations. Linear mixed effects modelling revealed effects of confounding factors such as reproductive condition on NRRT (gonad stage (p < 0.001)). Higher prevalence of inflammation, brown cells and epithelial thinning of the digestive gland was evident at Dublin and Wexford and this linked well with the Ih. Levels of contaminants were generally found to be low with few exceptions as were BE responses. Using the IR approach, Dublin was ranked as being most impacted while Shannon ranked the least impacted, this being consistent with the BE ranking.

Declines in TBT contamination in Irish coastal waters 1987-2011, using the dogwhelk (Nucella lapillus) as a biological indicator

Using the vas deferens sequence index (VDSI) and relative penis size index (RPSI) in dogwhelks (Nucella lapillus), imposex levels were assessed at 63 sites within 11 sea inlets during 2010/2011 and compared these with levels gathered since 1987. Sterile females (VDS>5.0) were found at 14 of the 63 sites and 47 sites (75%) met the EcoQO (VDSI<2.0). The absence of imposex in 'control' areas on the west coast is due to the lack of vessel paint applications or net dips with TBT being used as an active anti-fouling ingredient. A significant decline was observed following 2005 when comparing VDSI levels which is consistent with the decline of TBT usage. Current levels are consistent with an overall improvement towards achieving Good Environmental Status according to the requirements under the Marine Strategy Framework Directive.

Biomarkers: are realism and control mutually exclusive in integrated pollution assessment?

The conventional view of pollution monitoring is that any choice is a trade-off between realism and precision, as the control over confounding variables decreases with the increasing degree of organization of the test system. Dublin Bay is subject to considerable anthropogenic pressures and there have been many attempts to quantify the status of the system at organizational levels from DNA strand breaks (Comet) to the system itself (Ecological Network analysis, ENA). Using Dublin Bay as an example, the data show there was considerable variability at all levels of organization. At intracellular level, Lysosome Membrane Stability (LMS, assessed by Neutral Red Retention, NRR) varied almost 4-fold with season and individual condition, while the community level AZTI Marine biotic Index (AMBI) had a similar range within a single, supposedly homogeneous, site. Overall, there was no evidence that biomarkers of the lower levels of organisation reduced the variability of the measure, despite the extra control over influencing variables, nor was there any evidence that variability was additive at higher levels of organisation. This poses problems for management, especially given the fixed limits of Ecological Quality Standards (EQSs). Clearly while the integrated approach to pollution monitoring does offer the potential to link effects across the organizational range, it should also be possible to improve their capability by widening the database for reference values, particularly at the higher level of organization, and by process models, including the confounding variables found in the field, for those at lower level.

Application of congener based multi-matrix profiling techniques to identify potential PCDD/F sources in environmental samples from the Burrishoole Catchment in the West of Ireland

Homologue and congener profiles of PCDD/Fs in eels, passive sampler and sediment extracts from the Burrishoole, a rural upland catchment on the western Irish seaboard were compared with potential PCDD sources. ΣPCDD/F levels in eels ranged from 2.9 to 25.9 pg g(-1) wet weight, which are elevated compared to other Irish locations. The OCDD congener dominated the pattern of ΣPCDD/Fs in all matrices from Burrishoole. Passive samplers were successfully deployed to identify for the first time the presence in the water column of PCDD/Fs and dimethoxylated octachlorodiphenyl ether (diMeOoctaCDE), impurities found in pentachlorophenol (PCP) production. Principal component analysis (PCA) identified similarities between PCDD/F profiles in technical PCP mixtures and environmental samples from the Burrishoole region. Results strongly suggest residual PCDD contamination associated with historic local use of a dioxin contaminated product in the catchment area, with pentachlorophenol a strong candidate.

Assessment of biomarkers in Mytilus edulis to determine good environmental status for implementation of MSFD in Ireland

Candidate OSPAR/ICES recommended biomarkers at the level of the individual in Mytilus edulis for determination of good environmental status for MSFD were evaluated against contaminant levels at sites around Ireland. The sites chosen ranged from moderate to low pollution levels, but the actual ranking of the sites varied according to the contaminant levels present. At the most contaminated site, Cork, 4 out of 16 contaminants exceeded the EAC, while at Shannon, no EACs were exceeded. The SOS assay suggested that Cork was the healthiest site with a LT50 of 17.6 days, while SOS for Shannon was 15.6 days. Likewise, condition factors varied among sites and did not always correspond to contaminant-based status. There may be uncertainty in assigning status around the not good:good boundary. This raises potential difficulties not only in the biomarker/contaminant load relationship but also in the reliability of the biomarkers themselves and hence barriers meeting compliance levels.

A sensitive liquid chromatography/tandem mass spectrometry method for the determination of natural and synthetic steroid estrogens in seawater and marine biota, with a focus on proposed Water Framework Directive Environmental Quality Standards

RATIONALE

Trace levels of natural and synthetic steroid estrogens estrone (E1), 17β-estradiol (E2) and 17α-ethynyl estradiol (EE2) have been demonstrated to exert adverse effects in exposed organisms. E2 and EE2 have been proposed for inclusion in the Water Framework Directive (WFD) list of priority pollutants; however, the detection and accurate quantification of these compounds provide significant challenges, due to the low detection limits required.

METHODS

A sensitive method combining ultrasonication, solid-phase extraction (SPE) and liquid chromatography/tandem mass spectrometry, with electrospray ionisation in negative mode (LC/ESI-MS/MS), capable of determining E1, E2 and EE2 at concentrations between 0.07 and 60 ng/L for seawater and between 0.4 and 200 ng/g wet weight in Mytilus spp. is reported. Recoveries at the limit of quantification (LOQ) ranged from 95 to 102% and 88 to 100% for water and tissue, respectively. Salinity (12 to 35‰) and typical marine particulate matter loadings (between 10 and 100 mg/L) were not found to affect analyte recoveries.

RESULTS

The first detection of E1 by LC/MS/MS in Irish marine waters (Dublin Bay, at 0.76 ng/L) is reported. Steroids were not detected in Galway Bay, or in any mussel samples from Dublin, Galway and Clare. The level of E2 detected in the dissolved water phase was below the proposed WFD Environmental Quality Standard (EQS) in other surface waters.

CONCLUSIONS

The proposed method is suitable for the detection of E1, E2 and EE2 at biologically relevant concentrations and, due to the specificity offered, is not subject to potential interferences from endogenous E1 and E2 which often complicate the interpretation of estrogenic biomarker assays.

Accounting for the effects of lipids in stable isotope (δ13C and δ15N values) analysis of skin and blubber of balaenopterid whales

RATIONALE

Stable isotope values (δ(13)C and δ(15)N) of darted skin and blubber biopsies can shed light on habitat use and diet of cetaceans, which are otherwise difficult to study. Non-dietary factors affect isotopic variability, chiefly the depletion of (13)C due to the presence of (12)C-rich lipids. The efficacy of post hoc lipid-correction models (normalization) must be tested.

METHODS

For tissues with high natural lipid content (e.g., whale skin and blubber), chemical lipid extraction or normalization is necessary. C:N ratios, δ(13)C values and δ(15)N values were determined for duplicate control and lipid-extracted skin and blubber of fin (Balaenoptera physalus), humpback (Megaptera novaeangliae) and minke whales (B. acutorostrata) by continuous-flow elemental analysis isotope ratio mass spectrometry (CF-EA-IRMS). Six different normalization models were tested to correct δ(13)C values for the presence of lipids.

RESULTS

Following lipid extraction, significant increases in δ(13)C values were observed for both tissues in the three species. Significant increases were also found for δ(15)N values in minke whale skin and fin whale blubber. In fin whale skin, the δ(15)N values decreased, with no change observed in humpback whale skin. Non-linear models generally out-performed linear models and the suitability of models varied by species and tissue, indicating the need for high model specificity, even among these closely related taxa.

CONCLUSIONS

Given the poor predictive power of the models to estimate lipid-free δ(13)C values, and the unpredictable changes in δ(15)N values due to lipid-extraction, we recommend against arithmetical normalization in accounting for lipid effects on δ(13)C values for balaenopterid skin or blubber samples. Rather, we recommend that duplicate analysis of lipid-extracted (δ(13)C values) and non-treated tissues (δ(15)N values) be used.

Toxicological risks to humans of toxaphene residues in fish

A revised risk assessment for toxaphene was developed, based on the assumption that fish consumers are only exposed to toxaphene residues that differ substantially from technical toxaphene due to environmental degradation and metabolism. In vitro studies confirmed that both technical toxaphene and degraded toxaphene inhibit gap junctional intercellular communication that correlates with the mechanistic potential to cause tumor promotion. In vivo rat studies established the NOAEL for degraded and technical toxaphene at the highest dose tested in the bioassay. Toxaphene residue intakes from European fishery products were estimated and compared to the provisional tolerable daily intakes (TDIs) from various regulatory agencies including Canada, the United States, and Germany. The estimated intake was also compared to a new calculated provisional MATT pTDI. The MATT pTDI is based on new toxicological information (in vivo rat studies) developed on a model for environmental toxaphene residues rather than technical toxaphene. A MATT pTDI (1.08 mg total toxaphene for a person of 60 kg) for tumor promotion potency was adopted for use in Europe and is referred to here as the MATT pTDI. These new data result in a better estimate of safety and a higher TDI than previously used. Based on realistic fish consumption data and recent baseline concentration data of toxaphene in European fishery products, the toxaphene intake for the consumers of Germany, Ireland, Norway, and the Netherlands was estimated. For an average adult fish consumer, the average daily intake of toxaphene was estimated to be 1.2, 0.4, 0.5, and 0.2 µg for the consumers of Norway, Germany, Ireland, and the Netherlands, respectively. The toxaphene intake of these average fish consumers was far below the MATT pTDI of 1.08 mg/60 kg bw. In conclusion, based on the most relevant toxicological studies and the most realistic estimates of fish consumption and recent concentrations of toxaphene in European fishery products, adverse health effects are unlikely for the average European consumer of fishery products. In no case is the MATT pTDI exceeded.

Design of manikin for testing of residual-limb shape-capture method: technical note

Consensus is still lacking on how best to capture the shape of a residual limb. Computer-aided design systems have not proven more accurate, repeatable, or reliable than traditional plaster of paris methods. Research is limited in design, relates to clinical trials, and is based on opinions and clinical experience. Many outcome measurements are based on qualitative estimations of prosthetic fit or patient feedback rather than quantitative measurements. Research must identify the most accurate, repeatable, and reliable methods for residual-limb shape capture under conditions most likely to enhance socket fit. Measurement is difficult because a reference grid is required for identifying the residual limb's axis for ensuring direct comparison. This article describes a manikin production method for testing the shape capture of the residual limb. Diameters and volume were measured at specific levels with a programmable computer numerical control milling machine and a displacement tool, with a combined accuracy of 5 micrometers.

In vitro screening of organotin compounds and sediment extracts for cytotoxicity to fish cells

The present study reports an in vitro screening method for contaminants in sediment samples utilizing an RTG-2 cell line. This technique integrates cytotoxicity testing with analytical chemistry with the aim of achieving a toxicity evaluation of the sediment sample. The toxic effect of individual organotin (OT) compounds and their presence in the sediment sample is the focus of the present study; however, other contaminants are also discussed. The following OT compounds: tributyltin (TBT), dibutyltin (DBT), monobutyltin (MBT), triphenyltin (TPT), diphenyltin (DPT), and a sediment solvent extract are exposed to the RTG-2 fish cell line. Both the alamar blue (AB) and neutral red (NR) assays are used to assess cytotoxicity after 24-h and 96-h exposure. Methodology for preparation of a sediment solvent extract suitable for biological testing and analytical determination is also described. With the RTG-2 cells, the AB and NR assays had comparable sensitivity for each individual OT compound exposure after 24 h, with TPT being the most toxic compound tested. The individual OT compound concentrations required to induce a 50% toxic effect on the cells (369 ng ml⁻¹ TBT, 1,905 ng ml⁻¹ DBT) did not equate to the concentrations of these contaminants present in the sediment extract that induced a 50% effect on the cells (294 ng ml⁻¹ TBT, 109 ng ml⁻¹ DBT). The solvent extract therefore exhibited a greater toxicity, and this suggests that the toxic effects observed were not due to OT compounds alone. The presence of other contaminants in the solvent extract is confirmed with chemical analysis, warranting further toxicity testing of contaminant mixtures and exposure to the cell line to further elucidate a complete toxicity evaluation.

The occurrence of persistent chlorinated and brominated organic contaminants in the European eel (Anguilla anguilla) in Irish waters

The European eel (Anguilla anguilla) is a relatively high lipid, long lived species capable of living in a variety of brackish, fresh and marine habitats. As such, eels can accumulate organic pollutants and have been incorporated into environmental monitoring programs as a suitable "bioindicator" species for the determination of the levels of organic contaminants within different water bodies. The global eel stock is now in decline and while the cause of the collapse remains unidentified, it is likely to include a combination of anthropogenic mortality in addition to environmental degradation. This study provides valuable data on a range of contaminants (PCDD/Fs, PCBs, OCPs, PBDEs, HBCD, TBBPA and PBBs) and extractable lipid levels in eel muscle tissue collected from five Irish catchments. Extractable lipid levels were lower in the yellow eels compared to those in the silver eels. These levels were similar to those reported elsewhere and it has been posited that a decline in the lipid content in yellow eels may have consequences for the future viability of the stock. With the exception of higher substituted dioxins (especially OCDD), in three samples collected from one catchment (Burrishoole) in the West of Ireland, POP levels in general were determined to be low in eels from Irish waters compared to those in other countries.

Use of caged Nucella lapillus and Crassostrea gigas to monitor tributyltin-induced bioeffects in Irish coastal waters

Caging studies have been previously reported to be useful for providing valuable information on biological effects of mollusks over short periods of time where resident species are absent. The degree of imposex in caged dog whelk (Nucella lapillus), was measured using the vas deferens sequence index (VSDI) and the Relative Penis Size Index (RPSI) and the extent of shell thickening in caged Pacific oyster (Crassostrea gigas) was investigated at t = 0 and t = 18 weeks. Nucella lapillus, when provided with mussels as a food source at the control site at Omey Island on the west Irish coast, did not demonstrate imposex features, whereas those transplanted to port areas did. Dunmore East exhibited the highest level of imposex (3.25 VDSI and 2.37 RPSI). Shell thickening was evident in C. gigas transplanted to Dunmore East, with low effects evident at the control location, Omey Island, and Dublin Bay at t = 18 weeks. Dry weight whole-body concentrations of organotins were most elevated in all species held at Dunmore East compared with other locations. Greatest delta15N and delta13C enrichment was observed within the tissues of the predatory N. lapillus in all three test sites. Increased assimilation in the Dublin Bay oysters might have been influenced by the presence of more nutrients at this location. Surficial sediment organotin levels were most elevated in the Dunmore East <2-mm fraction (22,707 microg tributyltin/kg dry weight), whereas low organotin levels were determined from Dublin and Omey Island sediments. The valuable application of cost-effective caging techniques to deliver integrated biological effects and chemical measurements in the absence of resident gastropod populations in potential organotin/tributyltin hotspot locations is discussed.

Bioassay-directed fractionation of marine sediment solvent extracts from the east coast of Ireland

Crude solvent extracts were prepared from three sediment sites in Ireland namely Bull Lagoon, Dunmore East and Dublin Port. These were assayed with Tisbe battagliai and the Microtox system. The extracts were chemically characterised using a variety of analytical techniques for a suite of organic contaminants. Metals and organic contaminant concentration data are reported for the three sites. On the basis of determined toxicity and chemical analysis of these crude extracts, a further bioassay-directed fractionation (BDF) employing the Dunmore East crude organic extract was conducted in addition to chemical analysis. For the crude extracts, T. battagliai and Microtox system demonstrated an order of decreasing toxicity for each of the three sites to be Dublin Port>Dunmore East>Bull Lagoon. Microtox system EC10 values after 30min exposure were 1.08%, 11.6% and 26.9% solvent extract for these sites, respectively. Fractionation of the Dunmore East extract revealed that fraction 1 was the most toxic fraction to both the T. battagliai and the Microtox system demonstrating EC50's after 48 h and 30 min of 44.7% and 16.8% solvent extract for the T. battagliai and Microtox assays, respectively. T. battagliai however did show increased sensitivity to fraction 3 when comparing EC10 values and demonstrated an EC10 value of 17.8% solvent extract after 48h. Fraction 1 was shown to contain the highest quantity of the butyltins, in particular TBT in relation to fractions 2 and 3. A useful BDF technique was developed and employed in this study.

A test battery approach to the ecotoxicological evaluation of cadmium and copper employing a battery of marine bioassays

Heavy metals are ubiquitous contaminants of the marine environment and can accumulate and persist in sediments. The toxicity of metal contaminants in sediments to organisms is dependent on the bioavailability of the metals in both the water and sediment phases and the sensitivity of the organism to the metal exposure. This study investigated the effects of two metal contaminants of concern (CdCl(2) and CuCl(2)) on a battery of marine bioassays employed for sediment assessment. Cadmium, a known carcinogen and widespread marine pollutant, was found to be the least toxic of the two assayed metals in all in vivo tests. However, CdCl(2) was found to be more toxic to the fish cell lines PLHC-1 and RTG-2 than CuCl(2). Tisbe battagliai was the most sensitive species to both metals and the Microtox and cell lines were the least sensitive (cadmium was found to be three orders of magnitude less toxic to Vibrio fischeri than to T. battagliai). The sensitivity of Tetraselmis suecica to the two metals varied greatly. Marine microalgae are among the organisms that can tolerate higher levels of cadmium. This hypothesis is demonstrated in this study where it was not possible to derive an EC(50) value for CdCl(2) and the marine prasinophyte, T. suecica. Conversely, CuCl(2) was observed to be highly toxic to the marine alga, EC(50) of 1.19 mg l(-1). The genotoxic effect of Cu on the marine phytoplankton was evaluated using the Comet assay. Copper concentrations ranging from 0.25 to 2.50 mg l(-1) were used to evaluate the effects. DNA damage was measured as percent number of comets and normal cells. There was no significant DNA damage observed at any concentration of CuCl(2) tested and no correlation with growth inhibition and genetic damage was found.

An integrated approach to the toxicity assessment of Irish marine sediments: application of porewater Toxicity Identification Evaluation (TIE) to Irish marine sediments

An integrated approach to the ecotoxicological assessment of Irish marine sediments was carried out between 2004 and 2007. Phase I Toxicity Identification Evaluation (TIE) of sediment porewaters from two sites on the east coast of Ireland were conducted. Initial Tier I screening of three Irish sites identified the need for TIE after significant toxicity was observed with Tisbe battagliai and the Microtox assay at two of the assayed sites (Alexandra Basin and Dunmore East). Porewaters classified as toxic were characterised using four manipulations, ethylenediaminetetraacetic acid (EDTA) chelation, sodium thiosulphate addition, C(18) Solid Phase Extraction (SPE) and Cation Exchange (CE) SPE. Prior to initial testing, and TIE manipulations, all porewater samples were frozen at -20 degrees C for several months until required. After initial Tier I testing Alexandra Basin porewater was classified as highly toxic by both assays while Dunmore East porewater only warranted a TIE with T. battagliai. Results of TIE manipulations for Alexandra Basin porewater and the Microtox Basic test were inconclusive. The toxicity of the porewater in this assay was significantly reduced after freezing. Three experimental episodes were conducted with one month between each for the Alexandra Basin porewater. After each month of freezing the baseline toxicity was further reduced in the Microtox assay, therefore it was not possible to draw accurate conclusions on the nature of the active contaminants in the sample. However, toxicity to T. battalgiai did not change after storage of the porewater. The C(18) and CE SPE decreased the toxicity of Alexandra Basin porewater to the copepod indicating that both organic and cationic compounds (e.g. metals) were active in the sample. Dunmore East porewater was assayed with T. battalgiai and again a combination of organic and inorganic compounds were found to be partly responsible for the observed toxicity (C(18), CE SPE and EDTA reduced toxicity). Results from these TIEs provide insight into the complexity of interpreting marine TIE data from porewater studies where mixtures of unknown substances are present.

An integrated approach to the toxicity assessment of Irish marine sediments: validation of established marine bioassays for the monitoring of Irish marine sediments

This paper describes the ecotoxicological evaluation of marine sediments from three sites around Ireland representative of a range of contaminant burdens. A comprehensive assessment of potential sediment toxicity requires the consideration of multiple exposure phases. In addition to the evaluation of multi-exposure phases the use of a battery of multi-trophic test species has been advocated by a number of researchers as testing of single or few organisms may not detect toxicants with a specific mode of action. The Microtox solid phase test (SPT) and the 10-d acute amphipod test with Corophium volutator were used to assess whole sediment toxicity. Porewater and elutriates were assessed with the Microtox acute test, the marine prasinophyte Tetraselmis suecica, and the marine copepod Tisbe battagliai. Solvent extracts were assayed with the Microtox and T. battagliai acute tests. Alexandra Basin was identified as the most toxic site according to all tests, except the Microtox SPT which identified the Dunmore East site as being more toxic. However, it was not possible to correlate the observed ecotoxicological effects with a specific and/or class of contaminants based on sediment chemistry alone. Therefore porewaters found to elicit significant toxicity (Dunmore East and Alexandra Basin) with the test battery were selected for further TIE assessment with T. battalgiai and the Microtox system. The results of this study have important implications for risk assessment in estuarine and coastal waters in Ireland, where, at present the monitoring of sediment and water quality is predominantly reliant on chemical analysis alone.

Evaluation of tumour promoting potency of fish borne toxaphene residues, as compared to technical toxaphene and UV-irradiated toxaphene

In this study the potential impact of food chain-based biotransformation and physico-chemical weathering of toxaphene on its tumour promoting potential was investigated in vitro and in vivo. Human exposure to toxaphene is mainly through consumption of contaminated fish, therefore fish-borne residues of toxaphene (cod liver extract, CLE) were prepared by exposing cod to technical toxaphene (TT) for 63 days. UV-irradiated toxaphene (uvT) was included to represent a physico-chemical weathered toxaphene mixture. In vitro, TT, uvT and CLE all showed a dose- and time-dependent inhibition of gap junctional intercellular communication (GJIC) with a relative potency of CLE>TT=uvT. Tumour promoting potency was further studied in vivo in a medium term two-stage initiation/promotion bioassay in female Sprague-Dawley rats, using an increase in altered hepatic foci positive for glutathione-S-transferase-P (AHF-GST-P) as read out. No increase in AHF-GST-P occurred following exposure to either TT, uvT, or CLE, except for the positive control group (2,3,7,8-TCDD). Based on this study the no observed adverse effect level (NOAEL) for tumour promoting potency is at least 12.5mg/kg/week, or higher for CLE. Considering current human exposure levels in Europe it is doubtful that consumption of fish at current levels of toxaphene contamination give rise to human health risk.

Evaluation of the effect of shape on a contemporary CAD system

The TracerCAD system is one of the leading prosthetic CAD systems in the world and is increasingly used in clinics to replace traditional methods of residual limb shape capture. Accurate dimensional capture of the residuum is arguably the most important process in the production of a prosthetic socket. TracerCAD system accuracy has previously been tested on a cylindrical model but not a trans-tibial shape. Residual limbs are irregular in shape therefore it is important to assess if shape has an effect on the accuracy of data collected when using TracerCAD. The objective of this study is to investigate the accuracy of the TracerCAD system in measuring a model of a trans-tibial stump of known dimensions and volume. A model of a trans-tibial stump was produced and filled with plaster and measured using a data acquisition system with an accuracy of five micron (0.005 mm). The model was repeatedly traced using the TracerCAD system by an individual user. The mean value of measures taken by the dynamic indicator was calculated and compared to individual and mean values of TracerCAD measurement. Results showed that the TracerCAD measurement was not as consistent on the more complex trans-tibial model as for the cylindrical model.

A model compound study: the ecotoxicological evaluation of five organic contaminants employing a battery of marine bioassays

This paper describes the ecotoxicological evaluation of five organic contaminants frequently detected in marine sediments (tributyltin, triphenyltin, benzo[a]pyrene, fluoranthene, and PCB 153) using three marine species (Vibrio fischeri, Tetraselmis suecica, and Tisbe battagliai). The sensitivity of each species varied for all compounds. The triorganotins were consistently the most toxic to all species. The applicability of each test system to assess the acute toxicity of environmental contaminants and their use in Toxicity Identification Evaluation (TIE) is discussed. Suitability of the Microtox and T. battagliai tests for employment in TIE studies were further assessed through spiking experiments with tributyltin. Results demonstrated that the most effective treatment to remove organotin toxicity from the sample was the C18 resin. The results of this study have important implications for risk assessment in estuarine and coastal waters in Ireland, where, at present the monitoring of sediment and water quality is predominantly reliant on chemical analysis alone.

Magnetic resonance imaging technology in transtibial socket research: a pilot study

Investigations into the shape and volume of transtibial prosthetic sockets are complicated because of the difficulty in establishing an accurate reference grid. Magnetic resonance imaging (MRI) presents a possible solution to this problem. However, the reliability of MRI in defining the residual-limb/cast interface depends on the scanned image not being distorted by the materials present. We investigated the potential of MRI technology to establish the desired reference grid. Distortion from the so-called "chemical shift" may influence the MRI when certain materials are used during the casting process. These materials include plaster of paris (POP) and silicone (in the form of an interface liner). POP is commonly used to capture the shape of the residual limb. However, if the casting technique requires the use of a silicone liner, the liner is placed over the residual limb first and then the POP is applied over the liner. Experimental results indicate that the materials used do not distort or interfere with the scanned image. The object segmentation process that extracts the bone and skin from an MRI scan and enables the establishment of the required reference grid was explored. Results show that extracting the bone structure and using it as the reference grid to quantify the differences in volume and shape of the soft tissues of the residual limb is feasible.

Bioaccumulation and enantiomeric profiling of organochlorine pesticides and persistent organic pollutants in the killer whale (Orcinus orca) from British and Irish waters

Concentrations and enantiomeric profiles for a range of organochlorine compounds are reported in blubber samples from a number of individual killer whales (Orcinus orca) from British and Irish waters. Elevated contaminant levels and enriched isotopic ratios were determined in one individual whale sampled in the Scottish Western Isles compared to the others suggesting marine mammal based dietary influences. The potential application of isotopic ratios to model contaminant uptake, enantioselective enrichment and accumulation is demonstrated. Data are presented which provide information on enantioselective enrichment factors (EFs) for o,p'-DDT, alpha-HCH and toxaphene congeners CHB26 and CHB 50. This dataset further improves the current database on reported levels of a number of contaminants and provides additional background information on potential metabolic processes in killer whales from British and Irish waters.

Comparison of the results of four users of a contemporary CAD/CAM system

The objective of this study was to investigate the variation of measurements recorded when four different users of the TracerCAD system trace a model of known dimensions and volume. This complements a previous study where the accuracy and consistency of a single user was measured. Landmarks were added to indicate proximal, distal, anterior, medial and lateral regions of a specially manufactured cylindrical nylon 6.6 model. Four circumferential lines were added at regular intervals along the length of the cylinder with a view to calculating diameters and volumes relative to these landmarks. The model was measured using a comparator with guaranteed accuracy to one hundredth of a millimetre, and was traced using the TracerCAD system by four different users. The difference in mean volume between measured results and TracerCAD scans of differing users ranged to -3%. Individual trace volumes varied by up to -7.85%. In all volumes measured, 11 out of 12 maximum volume percentage differences measured greater than 2%, and of these, seven results showed maximum volume percentage difference to measure greater than 4%.

Evaluation of a contemporary CAD/CAM system

The objective of this study is to investigate the accuracy of the TracerCAD system in measuring a model of known dimensions and volumes. A cylindrical nylon 6.6 model was prepared. Landmarks were added to indicate proximal, distal, anterior, medial, and lateral. Four additional landmarks were added at regular intervals along the length of the cylinder with a view to calculating diameters and volumes relative to these landmarks. The model was measured using a comparator with a guaranteed accuracy of 0.01 mm and was traced using the TracerCAD system (Test 1). The test was repeated with the model rotated by 90 degrees (Test 2), to determine whether there were any effects related to the orientation of the model in relation to the transmitter. The difference in average volume between measured results and TracerCAD scans was between 0.20% and -1.96%. Individual trace volumes varied between -0.0085% and -4.50%. In all volumes measured in Tests 1 and 2, all maximum volume percentage differences measured greater than 3%.

Living with Marfan syndrome: coping with stigma

Social stigmatization can disrupt the ability of individuals with genetic conditions to successfully adapt to their situation. We offer data on perceptions of stigma from a cross-sectional survey of 174 adults with Marfan syndrome by self-report. Fifty-six respondents (32%) reported feeling discriminated against or socially devalued because of having Marfan syndrome. Endorsement of discrimination was significantly correlated with having depressive symptoms, low self-esteem, the view Marfan syndrome has had significant negative consequences on one's life, striae, and perceptions of workplace discrimination. Nearly 30% of respondents reported withdrawing from social situations that they anticipated would lead to feeling stigmatized, and 25% reported electing to keep their condition secret in potentially stigmatizing situations. Over 50% of respondents reported educating others about Marfan syndrome as a means of coping with their feelings of stigma, and endorsement of education was correlated with viewing involvement in the National Marfan Foundation as important. Instances of workplace discrimination were perceived by 20% of respondents, and 23% reported that they remained in a dissatisfying job due to having Marfan syndrome. Genetics professionals should actively engage patients with Marfan syndrome in discussions about social stigmatization and encourage use of coping strategies aimed at enhancing quality of life.

Baseline survey of concentrations of toxaphene congeners in fish from European waters

The European Union project "Investigation into the monitoring, analysis and toxicity of toxaphene"(MATT) began in 1997 involving participants from the Netherlands, Ireland, Norway and Germany. Concentration information, analytical methodology and statistical interpretation of 207 samples covering 23 different fish species from European waters are presented for three toxaphene indicator congeners: CHBs 26, 50 and 62 (CHB = chlorobornane). Concentrations for the Sigma3CHBs were more elevated in fish from more northern latitudes, such as the Barents and Norwegian Sea, compared to fish from Irish, Dutch and German waters. Concentrations were lowest in shellfish and in fish species having low lipid content and were highest in medium/high lipid species. Females from a number of fish species were shown to contain significantly higher concentrations than those observed in male fish. Overall no samples were shown to exceed existing German MRL legislation, with only one Greenland halibut sample shown to exceed Canadian TDI recommendations.

Measurement of the consistency of patellar-tendon-bearing cast rectification

The quality of fit of a trans-tibial patellar-tendon-bearing (PTB) socket may be influenced by consistency in casting, rectification or alignment. This paper quantifies, for the first time, the variations in the rectified casts between two experienced prosthetists and the variation between the rectified casts of each individual prosthetist. Prosthetists A and B observed the hand casting of a typical trans-tibial amputee. Each prosthetist was supplied with 5 previously measured duplicated plaster models. The two prosthetists rectified the supplied plaster models based on their own interpretation of basic rectification guidelines. Both prosthetists operated in isolation. The re-measured rectified plaster model data was compared with the unrectified data. The extent of rectification at each of 1800 locations per plaster model was calculated. In zones of major rectification, the mean difference between prosthetists was quantified as 2mm and the standard deviation (SD) about that mean was +/- 1mm for each prosthetist. The co-ordinates of the apex of the fibular head for the 10 modified casts indicated that the maximum variation was in the axial direction with a SD of 4.3mm for prosthetist A and a SD of 2.8mm for prosthetist B. The lengths of the 5 plaster models rectified by prosthetist A indicated a SD of 0.2mm whereas the lengths of the 5 plaster models rectified by prosthetist B indicated a SD of 2.9mm.

Pilot study: data-capturing consistency of two trans-tibial casting concepts, using a manikin stump model: a comparison between the hands-on PTB and hands-off ICECAST compact concepts

The quality of fit of a trans-tibial patellar tendon bearing (PTB) socket may be influenced by consistency in casting, rectification or alignment. For this study two distinctive different data-capturing concepts were tested in relation to prosthetist performance. The hands-on PTB and hands-off ICECAST compact concept were studied and compared for inter- and intra-prosthetist consistency using a specially designed manikin stump model. A purpose designed digitiser was used to scan a selected surface area of the produced models, 5 for each concept, 10 in total. The extent of casting consistency at each of 936 locations per plaster model was calculated and the level of consistency was quantified. This study has shown that by using the manikin model there is a clear indication that the investigated hands-off concept produces more consistent results than the hands-on concept.

Comparative tests to improve the gas chromatographic analysis of chlorobornanes in fish samples

A comparison was made between electron capture negative ionization quadrupole mass spectrometry (ECNI-MS) and electron capture detection (ECD) with regard to repeatability and reproducibility for the gas chromatographic (GC) analysis of toxaphene congeners [chlorobornanes (CHBs)]. The tests, including standard solutions and several cleaned fish extracts, showed larger relative standard deviations (RSDs) for the repeatability of ECNI-MS but no differences in the reproducibility of the 2 techniques. The sensitivity of the GC-ECNI-MS was considerably better than that of GC/ECD. Four stepwise-designed comparative tests were also conducted on GC analysis, cleanup, and the complete method. The results showed that, according to the current state-of-the-art, coefficients of variation for the between-laboratory performance were not < 20% and were usually between 20 and 30%. In spite of separation problems, e.g., for CHB 26, which cannot be separated into a single-component peak, a 95% methyl 5% phenyl polysiloxane (CP Sil 8) column was preferred to more polar columns for the analysis of CHBs 26, 40, 41, 44, 50, and 62. CHB 62 was more difficult to determine than CHB 26 and 50. Addition of the CHBs 40, 41, and 44 to the standard set of 3 chlorobornanes (26, 50, and 62) resulted in more separation problems. A 3-step cleanup method was recommended.

Comparative Tests To Improve the Gas Chromatographic Analysis of Chlorobornanes in Fish Samples

A comparison was made between electron capture negative ionization quadrupole mass spectrometry (ECNI-MS) and electron capture detection (ECD) with regard to repeatability and reproducibility for the gas chromatographic (GC) analysis of toxaphene congeners [chlorobornanes (CHBs)]. The tests, including standard solutions and several cleaned fish extracts, showed larger relative standard deviations (RSDs) for the repeatability of ECNI-MS but no differences in the reproducibility of the 2 techniques. The sensitivity of the GC-ECNI-MS was considerably better than that of GC/ECD. Four stepwise-designed comparative tests were also conducted on GC analysis, cleanup, and the complete method. The results showed that, according to the current state-of-the-art, coefficients of variation for the between-laboratory performance were not &lt;20% and were usually between 20 and 30%. In spite of separation problems, e.g., for CHB 26, which cannot be separated into a single-component peak, a 95% methyl 5% phenyl polysiloxane (CP Sil 8) column was preferred to more polar columns for the analysis of CHBs 26, 40, 41, 44, 50, and 62. CHB 62 was more difficult to determine than CHB 26 and 50. Addition of the CHBs 40, 41, and 44 to the standard set of 3 chlorobornanes (26, 50, and 62) resulted in more separation problems. A 3-step cleanup method was recommended.

Genetic basis of transferase-deficient galactosaemia in Ireland and the population history of the Irish Travellers

Transferase-deficient galactosaemia, resulting from deficient activity of galactose-1-phosphate uridyltransferase (GALT), is relatively common among the Travellers, an endogamous group of commercial/industrial nomads within the Irish population. This study has estimated the incidence of classical transferase-deficient galactosaemia in Ireland and determined the underlying GALT mutation spectrum in the Irish population and in the Traveller group. Based upon a survey of newborn screening records, the incidence of classical transferase-deficient galactosaemia was estimated to be 1 in 480 and 1 in 30,000 among the Traveller and non-Traveller communities respectively. Fifty-six classical galactosaemic patients were screened for mutation in the GALT locus by standard molecular methods. Q188R was the sole mutant allele among the Travellers and the majority mutant allele among the non-Travellers (89.1%). Of the five non-Q188R mutant alleles in the non-Traveller group, one was R333G and one F194L with three remaining uncharacterized. Anonymous population screening has shown the Q188R carrier frequency to be 0.092 or 1 in 11 among the Travellers as compared with 0.009 or 1 in 107 among the non-Travellers. The Q188R mutation was shown to be in linkage disequilibrium with a Sac I RFLP flanking exon 6 of the GALT gene. This represents the first molecular genetic description of classical transferase-deficient galactosaemia in Ireland and raises intriguing questions concerning the genetic history of the Irish Travellers.

Analysis of body-device interface forces in the sagittal plane for patients wearing ankle-foot orthoses

An ankle-foot orthosis (AFO) is employed principally to treat musculoskeletal disorders of the ankle and/or subtalar joints although, occasionally, it may be prescribed to provide stance phase control of the knee. In order to function satisfactorily, an AFO must apply appropriate forces to the lower leg in a manner which does not cause local tissue damage or discomfort. Equally the leg will apply forces to the AFO which it must be capable of withstanding without breakage or loss of function. Thus it is useful to know where the body-device interface forces act during walking and to be able to estimate their magnitudes. This is not well understood and has not been satisfactorily documented. This paper explains the force actions between the AFO and the leg, in the sagittal plane, where there is absence of muscle power. Furthermore, it explores the possibility of estimating the magnitudes of these forces. It is found that the forces are greatest when orthotic assistance is needed to compensate for plantar flexor insufficiency in late stance phase. On the other hand, where the AFO is used to support the foot, in the absence of dorsiflexion power in swing phase, the forces are relatively small. Understanding these force levels is relevant to the design of the AFO in terms of choice and use of materials and components.