A review of combined sewer overflows as a source of wastewater-derived emerging contaminants in the environment and their management.

Emerging contaminants such as pharmaceuticals, illicit drugs and personal care products can be released to the environment in untreated wastewater/stormwater mixtures following storm events. The frequency and intensity of combined sewer overflows (CSOs) has increased in some areas due to increasing urbanisation and climate change. Therefore, this review provides an up-to-date overview on CSOs as an environmental source of emerging contaminants. Other than compounds with high removal, those chiral species subject to enantioselective changes (i.e. degradation or inversion) during wastewater treatment can be effective markers of CSO discharge in the environment. A proposed framework for the selection of emerging contaminants as markers of CSOs is outlined. Studies have demonstrated that CSOs can be the main source of emerging contaminants with high removal efficiency during wastewater treatment (e.g. > 90%). However, the impact of CSOs on the environment is location specific and requires decision-making on their appropriate management at catchment level. This process would be aided by further studies on CSOs which incorporate the monitoring of emerging contaminants and their effects in the environment with those more routinely monitored pollutants (e.g. pathogens and priority substances). Mitigation and treatment strategies for emerging contaminants in CSOs are also discussed

Analysis, fate and toxicity of chiral non-steroidal anti-inflammatory drugs in wastewaters and the environment: a review.

Non-steroidal anti-inflammatory drugs (NSAIDs) are found in the aquatic environment globally. Such drugs including naproxen, ibuprofen and ketoprofen are chiral molecules. Enantiomers of those drugs have identical physicochemical properties but can behave and interact differently in chiral environments due to differences in their three-dimensional shape. This results in enantiospecific differences in environmental fate and toxicity, which is often overlooked. Therefore, we review the analytical methods, occurrence and fate, and toxicity of chiral non-steroidal anti-inflammatory drugs at the enantiomeric level. The advancement of enantioselective chromatography methods, particularly the use of polysaccharide-based stationary phases, has enabled trace determination of enantiomers in complex environmental matrices. Macrocosm and microcosm studies of engineered and natural environments revealed that such drugs can undergo both enantioselective degradation and chiral inversion. Enantioselectivity has been reported during wastewater treatment, in surface waters and in agricultural soils. The use of microcosms spiked with individual enantiomers over racemates is essential to evaluate these degradation and inversion fate processes. The chiral inversion process whereby one enantiomer converts into its antipode can be significant if the more toxic enantiomers are formed. Existing enantiospecific effect studies report less than an order of magnitude difference in enantiomer toxicity. However, toxicity data for enantiomers are limited and further research is needed to better appreciate the environmental risk at the enantiomeric level

Enantiospecific behaviour of chiral drugs in soil.

The importance of stereochemistry on the behaviour and effects of chiral pharmaceutical and illicit drugs in amended agricultural soils has been over looked to date. Therefore, this study was aimed at investigating the enantiospecific behaviour of a chemically diverse range of chiral drugs including naproxen, ibuprofen, salbutamol, bisoprolol, metoprolol, propranolol, acebutolol, atenolol, chlorpheniramine, amphetamine, fluoxetine and citalopram in soil microcosms. Considerable changes of the enantiomeric composition of ibuprofen, naproxen, atenolol, acebutolol and amphetamine were observed within 56 d. This is significant as enantiomer enrichment can favour the pharmacologically active (e.g., S(−)-atenolol) or less/non-active forms of the drug (e.g., R(−)-amphetamine). Single enantiomer microcosms showed enantiospecific degradation was responsible for enantiomer enrichment of atenolol and amphetamine. However, naproxen and ibuprofen enantiomers were subject to chiral inversion whereby one enantiomer converts to its antipode. Interestingly, chiral inversion was bidirectional and this is the first time it is reported in soil. Therefore, introduction of the less active enantiomer to soil through irrigation with reclaimed wastewater or biosolids as fertiliser can result in the formation of its active enantiomer, or vice versa. This phenomenon needs considered in risk assessment frameworks to avoid underestimating the risk posed by chiral drugs in amended soils

Multi-residue enantioselective analysis of chiral drugs in freshwater sediments.

Pharmaceutical and illicit drugs are emerging contaminants found in the environment globally. Many are chiral and stereochemistry plays an important role on their environmental fate and effects. However, investigations at the enantiomeric level are limited, particularly for complex particulate matrices such as sediments. This is due to further sample processing requirements and a lack of suitable analytical methods. Therefore, here a new enantioselective methodology is proposed for 15 drugs in sediment. Sample treatment by accelerated solvent extraction and solid phase extraction was critical for subsequent enantioselective separations. Using liquid chromatography–tandem mass spectrometry, a Chiral-V enantioselective column enabled multi-residue separations of anti-depressants, beta-blockers, beta-agonist, anti-histamine and stimulants. Method trueness for all enantiomers was 86–121% and method quantitation limits were below 3 ng g−1 dry weight. Application of the method revealed the enantiomeric composition of fluoxetine, amphetamine, propranolol, venlafaxine and citalopram in sediment for the first time. All drugs except venlafaxine were present in non-racemic form, i.e. unequal enantiomer concentrations. This is significant considering drug toxicity towards benthic organisms could be enantiospecific

Protocol for the effective feedback to improve primary care prescribing safety (EFIPPS) study : a cluster randomised controlled trial using ePrescribing data

High-risk prescribing in primary care is common and causes considerable harm. Feedback interventions to improve care are attractive because they are relatively cheap to widely implement. There is good evidence that feedback has small to moderate effects, but the most recent Cochrane review called for more high-quality, large trials that explicitly test different forms of feedback. The study is a three-arm cluster-randomised trial with general practices being randomised and outcomes measured at patient level. 262 practices in three Scottish Health Board areas have been randomised (94% of all possible practices). The two active arms receive different forms of prescribing safety data feedback, with rates of high-risk prescribing compared with a ‘usual care’ arm. Sample size estimation used baseline data from participating practices. With 85 practices randomised to each arm, then there is 93% power to detect a 25% difference in the percentage of high-risk prescribing (from 6.1% to 4.5%) between the usual care arm and each intervention arm. The primary outcome is a composite of six high-risk prescribing measures (antipsychotic prescribing to people aged ≥75 years; non-steroidal anti-inflammatory drug (NSAID) prescribing to people aged ≥75 without gastroprotection; NSAID prescribing to people prescribed aspirin/clopidogrel without gastroprotection; NSAID prescribing to people prescribed an ACE inhibitor/angiotensin receptor blocker and a diuretic; NSAID prescription to people prescribed an oral anticoagulant without gastroprotection; aspirin/clopidogrel prescription to people prescribed an oral anticoagulant without gastroprotection). The primary analysis will use multilevel modelling to account for repeated measurement of outcomes in patients clustered within practices. The study was reviewed and approved by the NHS Tayside Committee on Medical Research Ethics B (11/ES/0001). The study will be disseminated via a final report to the funder with a publicly available research summary, and peer reviewed publications

Multi-residue enantioselective determination of emerging drug contaminants in seawater by solid phase extraction and liquid chromatography-tandem mass spectrometry.

This study proposes a new multi-residue enantioselective method for the determination of emerging drug contaminants in sea water by solid phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). To achieve satisfactory enantiomeric separation with a vancomycin stationary phase it was essential to limit sodium chloride in extracted samples to [less than] 1 µg injection-1. This was achieved through a straightforward SPE method using a 50 mL water wash volume and analyte elution in acetonitrile. A Chiral-V enantioselective column (150 x 2.1mm; 2.7µm particle size) operated in polar ionic mode enabled simultaneous drug separations in 30 minutes. Analytes with enantioresolution E$ were the stimulants amphetamine and methamphetamine, the beta-agonist salbutamol, the beta-blockers propranolol, sotalol and acebutolol, the anti-depressants fluoxetine, venlafaxine, desmethylvenlafaxine and citalopram, and the antihistamine chlorpheniramine. Method quantitation limits were [less than] 10 ng L-1 and method trueness was 80-110% for most analytes. The method was applied to samples from the Forth and Clyde estuaries, Scotland. Chiral drugs were present at concentrations in the range 4-159 ng L-1 and several were in non-racemic form (enantiomeric fraction G 0.50) demonstrating enantiomer enrichment. This emphasises the need for further enantiospecific drug exposure and effect studies in the marine environment

A review on emerging contaminants in wastewaters and the environment: current knowledge, understudied areas and recommendations for future monitoring.

This review identifies understudied areas of emerging contaminant (EC) research in wastewaters and the environment, and recommends direction for future monitoring. Non-regulated trace organic ECs including pharmaceuticals, illicit drugs and personal care products are focused on due to ongoing policy initiatives and the expectant broadening of environmental legislation. These ECs are ubiquitous in the aquatic environment, mainly derived from the discharge of municipal wastewater effluents. Their presence is of concern due to the possible ecological impact (e.g., endocrine disruption) to biota within the environment. To better understand their fate in wastewaters and in the environment, a standardised approach to sampling is needed. This ensures representative data is attained and facilitates a better understanding of spatial and temporal trends of EC occurrence. During wastewater treatment, there is a lack of suspended particulate matter analysis due to further preparation requirements and a lack of good analytical approaches. This results in the under-reporting of several ECs entering wastewater treatment works (WwTWs) and the aquatic environment. Also, sludge can act as a concentrating medium for some chemicals during wastewater treatment. The majority of treated sludge is applied directly to agricultural land without analysis for ECs. As a result there is a paucity of information on the fate of ECs in soils and consequently, there has been no driver to investigate the toxicity to exposed terrestrial organisms. Therefore a more holistic approach to environmental monitoring is required, such that the fate and impact of ECs in all exposed environmental compartments are studied. The traditional analytical approach of applying targeted screening with low resolution mass spectrometry (e.g., triple quadrupoles) results in numerous chemicals such as transformation products going undetected. These can exhibit similar toxicity to the parent EC, demonstrating the necessity of using an integrated analytical approach which compliments targeted and non-targeted screening with biological assays to measure ecological impact. With respect to current toxicity testing protocols, failure to consider the enantiomeric distribution of chiral compounds found in the environment, and the possible toxicological differences between enantiomers is concerning. Such information is essential for the development of more accurate environmental risk assessment

Stereoselective LC-MS/MS methodologies for environmental analysis of chiral pesticides.

Chiral pesticides can exert stereospecific toxicity in contaminated environmental compartments. Therefore, measuring pesticides at the enantiomeric level is essential to assess the risk posed to exposed organisms, including humans. In recent years, there has been rapid progress on the development and application of stereoselective liquid chromatography-tandem mass spectrometry (LC-MS/MS) methodologies for monitoring pesticides in the environment. Coupling chiral LC separations with MS/MS detection enables trace enantiomeric determination of pesticides in complex environmental matrices. The intent of this review is to provide an up-to-date synopsis on recent advances of stereoselective LC-MS/MS methodologies for pesticide analysis. Key aspects of these methodologies discussed include sample storage and extraction method, stationary phases for separation, multi-residue separations, and method of quantitation. Finally, future trends in this rapidly growing field of analytical chemistry research are outlined

Using a bioenergetic model to set waterfowl habitat objectives for the Fraser River delta

The Fraser River Estuary is a major link in a chain of Pacific coastal habitats that support migrating and wintering waterfowl, and many birds converge here during northward and southward travels. Between 800,000 and 2.3 million waterfowl use the estuary from September through April, including significant populations of American wigeon, mallard, northern pintail, surf scoter, snow goose and brant. Waterfowl mainly use agricultural lands, freshwater and brackish wetlands, and intertidal habitats such as eelgrass beds, all of which continue to be lost or degraded by population growth and urban sprawl. We used a bioenergetic model (TRUEMET) to explicitly link waterfowl population objectives to habitat objectives for farmland conservation. TRUEMET indicates whether there is a habitat surplus or deficit for a given population level. We combined five of the most abundant species into two foraging guilds: ‘grazers’ included American wigeon and snow goose, and ‘dabblers’ included mallard, northern pintail and green-winged teal. We assessed conditions as of 2009 and tested a variety of scenarios involving changes in habitat availability, including future losses of agricultural or intertidal habitats. Model results indicated that grazers experienced an excess of energy through the nonbreeding season, but this was predicted to become to a deficit by midwinter within 20 years under likely scenarios. For dabblers, the demand exceeded supply by December, and the situation only worsened under future scenarios. Ensuring their continuing presence at current levels in the face of growing development stressors will require a multi-faceted conservation strategy for both intertidal and farmland conservation. We set a conservative foraging habitat objective of 50% of the energy needs of waterfowl on agricultural lands during the migrating and wintering periods, which equates to 15,000 x10^6 kcal of energy. From a habitat program perspective, this will require protecting farmlands and encouraging green forage cropping on the broader landscape