Fate and transport of polychlorinated biphenyls (PCBs) in the River Thames catchment – insights from a coupled multimedia fate and hydrobiogeochemical transport model

The fate of persistent organic pollutants (POPs) in riverine environments is strongly influenced by hydrology (including flooding) and fluxes of sediments and organic carbon. Coupling multimedia fate models (MMFMs) and hydrobiogeochemical transport models offers unique opportunities for understanding the environmental behaviour of POPs. While MMFMs are widely used for simulating the fate and transport of legacy and emerging pollutants, they use greatly simplified representations of climate, hydrology and biogeochemical processes. Using additional information about weather, river flows and water chemistry in hydrobiogeochemical transport models can lead to new insights about POP behaviour in rivers. As most riverine POPs are associated with suspended sediments (SS) or dissolved organic carbon (DOC), coupled models simulating SS and DOC can provide additional insights about POPs behaviour. Coupled simulations of river flow, DOC, SS and POP dynamics offer the possibility of improved predictions of contaminant fate and fluxes by leveraging the additional information in routine water quality time series. Here, we present an application of a daily time step dynamic coupled multimedia fate and hydrobiogeochemical transport model (The Integrated Catchment (INCA) Contaminants model) to simulate the behaviour of selected PCB congeners in the River Thames (UK). This is a follow-up to an earlier study where a Level III fugacity model was used to simulate PCB behaviour in the Thames. While coupled models are more complex to apply, we show that they can lead to much better representation of POPs dynamics. The present study shows the importance of accurate sediment and organic carbon simulations to successfully predict riverine PCB transport. Furthermore, it demonstrates the important impact of short-term weather variation on PCB movement through the environment. Specifically, it shows the consequences of the severe flooding, which occurred in early 2014 on sediment PCB concentrations in the River Thames

In Situ Catchment Scale Sampling of Emerging Contaminants Using Diffusive Gradients in Thin Films (DGT) and Traditional Grab Sampling:A Case Study of the River Thames, UK

The in situ passive sampling technique, diffusive gradients in thin films (DGT), confronts many of the challenges associated with current sampling methods used for emerging contaminants (ECs) in aquatic systems. This study compared DGT and grab sampling for their suitability to screen and monitor ECs at the catchment scale in the River Thames system (U.K.) and explored their sources and environmental fate. The ubiquitous presence of endocrine disrupting chemicals, parabens, and their metabolites is of concern. This study is the first to report organophosphate esters (OPEs) in the study area. TEP (summer 13-160 and winter 18-46, ng/L) and TCPP (summer 242-4282 and winter 215-854, ng/L) were the main OPEs. For chemicals which were relatively stable in the rivers, DGT and grab sampling were in good agreement. For chemicals which showed high variation in water bodies, DGT provided a better integral of loadings and exposure than grab sampling. DGT was not as sensitive as grab sampling under the procedures employed here, but there are several options to improve it to give comparable/better performance. DGT samples require shorter preparation time for analysis in the laboratory than grab samples. Overall, DGT can be a powerful tool to characterize ECs throughout a large dynamic water system

Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

Initial predictions of the concentrations and distribution of 17β-oestradiol, oestrone and ethinyl oestradiol in 3 English rivers

The application of the EXAMS model to estimate the likely distribution of the steroid oestrogens, 17β-oestradiol, oestrone and ethinyl-oestradiol in the Rivers Thames, Calder and Aire, U.K. is described. The model uses parameters estimated from laboratory measurements using material collected from each of the three rivers or from the literature. Total concentrations in the water column were predicted to be similar for 17β-oestradiol and oestrone and an order of magnitude less for ethinyl-oestradiol, reflecting the difference in the sewage input loads of the chemicals used in the models. Concentrations under average conditions were predicted to (a) be found mainly in the dissolved phase and (b) to vary between 0.21 and 0.37 ng l−1 for 17β-oestradiol, 0.27 and 0.44 ng l−1 for oestrone and 0.024 and 0.038 ng l−1 for ethinyl-oestradiol. Under low-flow conditions, predicted concentrations increased by a factor of 4 to 10 times the average concentrations at the point of discharge. Predicted degradation processes in the water column were only significant under low-flow conditions and volatilization was negligible. A simple assessment of the model sensitivity to selected parameters identified those that were most significant in determining the distribution of the chemicals

The sorption potential of octylphenol, a xenobiotic oestrogen, to suspended and bed-sediments collected from industrial and rural reaches of three English rivers

Laboratory batch techniques were used to study the sorptive behaviour of 4-t-octylphenol (OP), a xenobiotic with oestrogenic properties, to sediments from three English rivers of contrasting water quality. Samples were taken from industrially polluted lower reaches of the Aire and Calder rivers, in the Humber catchment, as well as a rural reach of the River Thames, in Oxfordshire in the South of England. The results showed that given either sufficient time or mixing, a large proportion of OP in solution will sorb to the bed-sediments, with distribution coefficients (Kd) of 6–700 l kg−1 and organic carbon normalised partition coefficients (Koc) 3500–18 000 l kg−1. The sediments which sorbed the highest quantities of OP had higher total organic carbon and a greater proportion of clay and silt particles. There was evidence in some bed-sediments of a sorption-desorption hysteresis effect between OP and sediment. The suspended sediments, on a carbon for carbon basis, adsorbed 5–35 times more OP than their respective bed-sediments in the Aire and Calder rivers: microscopic examination suggested that the suspended sediments were predominantly organic aggregates. The suspended sediments of the Thames adsorbed far less OP than those of the Aire and Calder: microscopic examination revealed these suspended sediments to be largely algae. The work predicts that suspended sediments may play a key role in the fate of OP in the industrial reaches of English Rivers. In the comparatively rural reach of the Thames, a higher proportion of OP might be predicted to remain free in solution

Determination of cyclophosphamide and ifosfamide in sewage effluent by stable isotope-dilution liquid chromatography-tandem mass spectrometry

A reliable and specific method was developed for the determination of the cytotoxic drugs cyclophosphamide and ifosfamide in sewage effluent. The most successful combination was found to be Strata-X solid-phase extraction followed by Florisil® clean-up with analysis by liquid chromatography–tandem mass spectrometry. Quantification by internal standardisation was achieved using custom synthesised d4-cyclophophosphamide. The mass spectrometer was operated in highly selective reaction monitoring (HSRM) mode, which significantly reduced matrix noise and improved sensitivity. Although it suffered from some ionisation suppression, electrospray ionisation (ESI) was found to give an order of magnitude better sensitivity in terms of limit of detection than atmospheric pressure chemical ionisation (APCI). Using final effluent from two different sewage treatment plants, the method was validated following official European guidelines and shown to be a high performance tool for routine analysis at the sub-nanogram per litre level. Depending on the matrix, the limit of detection for cyclophosphamide was between 0.03 ng/L and 0.12 ng/L and for ifosfamide between 0.05 ng/L and 0.09 ng/L. For cyclophosphamide the accuracy and precision, tested at 1.7 ng/L, were 98–109% and ≤13%, CV respectively. For ifosfamide the accuracy and precision, tested at 1.1 ng/L, were 98–113% and ≤15% CV, respectively. Depending on the sample matrix the absolute recovery of the internal standard was between 57% and 70%. The method was tested by analysis of spot samples taken from the final effluent discharges of two sewage treatment plants; the first using a conventional trickling filter treatment process and second employing activated sludge followed by ultra violet treatment. Cyclophosphamide was detected at 0.19 ng/L at the first plant and at the second detected at 3.7 ng/L and 3.5 ng/L, before and after the UV treatment process; ifosfamide was not detectable at either plant