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.

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), 17ß-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.

High proportions of inorganic arsenic in Laminaria digitata but not in Ascophyllum nodosum samples from Ireland.

Seaweed can accumulate inorganic arsenic (iAs) from seawater as hydrogen arsenate (HAsO42-) in place of the phosphate anion (HPO42-). While it is rapidly metabolised to organoarsenic species, predominantly arsenosugars and arsenolipids, iAs may be present in seaweed biomass and this poses a potential health concern for consumers of seaweed products. Here, the distribution of total (AsTOT) and iAs was determined in thallus parts of the kelp Laminaria digitata and the intertidal fucoid Ascophyllum nodosum (both Phaeophyceae) using inductively-coupled plasma mass spectrometry (ICP-MS) and high performance liquid chromatography - ICP-MS (HPLC-ICP-MS). AsTOT ranged from 36 to 131 mg kg-1 dry weight (DW) in L. digitata, and from 38 to 111 mg kg-1 DW in A. nodosum, with no statistically significant differences between different thallus parts. iAs was detected in all A. nodosum samples, comprising less than 1% of the AsTOT content. Concentrations of iAs in L. digitata were significantly higher, ranging from 2.2 to 87 mg kg-1, increasing through the thallus from the stipe to the decaying distal blades. iAs comprised more than 50% of AsTOT in the middle to decaying distal blades. This finding has potential implications for harvesting, processing and use of Laminaria digitata in agri-, food and health applications.

A field deployable method for a rapid screening analysis of inorganic arsenic in seaweed.

Inorganic arsenic (iAs) in 13 store-bought edible seaweed samples and 34 dried kelp (Laminaria digitata) samples was determined by a newly developed, field-deployable method (FDM) with the aid of a field test kit for arsenic in water. Results from the FDM were compared to results from speciation analysis achieved by using high performance liquid chromatography coupled to inductively coupled plasma mass spectrometry (HPLC-ICP-MS). The FDM consisted of a simple extraction method using diluted HNO3 to quantitatively extract iAs without decomposing the organoarsenicals to iAs followed by the selective volatilisation of iAs as arsine (AsH3) and subsequent chemo-trapping on a filter paper soaked in mercury bromide (HgBr2) solution. Method optimization with a sub-set of samples showed 80-94% iAs recovery with the FDM with no matrix effect from organo-arsenic species in the form of dimethylarsinic acid (DMA) on the iAs concentration. The method displayed good reproducibility with an average error of ±19% and validation by HPLC-ICP-MS showed that the results from the FDM were comparable (slope = 1.03, R2 = 0.70) to those from speciation analysis with no bias. The FDM can be conducted within an hour and the observed limit of quantification was around 0.05 mg kg-1 (dry weight). This method is well suited for on-site monitoring of iAs in seaweed before it is harvested and can thus be recommended for use as a screening method for iAs in seaweed. Graphical abstractScreening seaweed for their inorganic arsenic concentration within one hour without bias has been made possible in the field by using a field deployable arsenic kit. Its accuracy and precision was compared to HPLC-ICPMS.

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.

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.