Emerging contaminants in waters and soils, practical considerations: sampling, analysis and consequences (2015)
Meeting report by James Lymer (ECG), Richard Allen (WSF), Kevin Pryor (WSF), Stephen Mudge (INEF)
ECG Bulletin July 2015
ECG Bulletin July 2015
This scientific meeting aimed to present a number of perspectives on the chemical sciences of emerging contaminants in soil and water environments. It was jointly organised by the RSC Environmental Chemistry Group (ECG), the RSC Water Science Forum (WSF) and the International Network of Environmental Forensics (INEF), and was held at The Source, Sheffield on 4th March 2015. Fifty-six delegates attended from a wide range of organisations including consultancies, regulators and academia.
Environmental contaminants may be broadly classified into two groups:
Common Environmental Contaminants are substances with known chemical and toxicology properties, such as trichloroethene, that are present in the environment due to historic lack of regulation, inadequate use and storage, and waste disposal. In the UK. their use pre-dated the Environmental Protection Act 1990, and they are now subject to remediation in soil and groundwater systems. These substances are now largely banned from use or are tightly regulated for use by operators, and in their treatment/disposal by waste companies through Environmental Permitting Regulations (as amended), and hence are less likely to enter the environment.
Contaminants of Emerging Concern are substances not previously considered or known to be significant in the environment and may have no regulatory standard. Examples include pharmaceuticals and personal care products. Due to improved monitoring techniques and increasingly sensitive analytical methods, more emerging contaminants are being detected in the environment, particularly in surface water and groundwater. Emerging contaminants can be broadly defined as any synthetic or naturally occurring chemical or microorganism that is not commonly monitored in the environment but has the potential to enter the environment and cause known or suspected adverse ecological and/or human health effects.
Environmental contaminants may be broadly classified into two groups:
Common Environmental Contaminants are substances with known chemical and toxicology properties, such as trichloroethene, that are present in the environment due to historic lack of regulation, inadequate use and storage, and waste disposal. In the UK. their use pre-dated the Environmental Protection Act 1990, and they are now subject to remediation in soil and groundwater systems. These substances are now largely banned from use or are tightly regulated for use by operators, and in their treatment/disposal by waste companies through Environmental Permitting Regulations (as amended), and hence are less likely to enter the environment.
Contaminants of Emerging Concern are substances not previously considered or known to be significant in the environment and may have no regulatory standard. Examples include pharmaceuticals and personal care products. Due to improved monitoring techniques and increasingly sensitive analytical methods, more emerging contaminants are being detected in the environment, particularly in surface water and groundwater. Emerging contaminants can be broadly defined as any synthetic or naturally occurring chemical or microorganism that is not commonly monitored in the environment but has the potential to enter the environment and cause known or suspected adverse ecological and/or human health effects.
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In the developed world, there has been a gradual decrease in the environmental concentrations of common environmental contaminants such as heavy metals, polychlorinated biphenyls (PCBs), dioxins, and polyaromatic hydrocarbons (PAHs). This improvement is largely due to stricter regulations with improved monitoring, cleaner industrial processes and waste disposal practices. There is a now a focus on contaminants of emerging concern.
Many of these newly recognized contaminants are produced industrially yet are dispersed to the environment from domestic, commercial, and industrial use including pesticide distribution to land, wastewater treatment effluent discharges, landfill sites, and sewage sludge spreading to land. |
Intake of raw water at a water treatment plant. Credit: Chaiyapruk Chanwatthana/Shutterstock
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Some emerging contaminants are recalcitrant to conventional sewage treatment or drinking water treatment. Many are small and/or very polar molecules, which are difficult to remove by granular activated carbon filtration methods. Key receptors to these contaminants are humans who consume drinking water sourced from contaminated water and aquatic ecology.
Rakesh Kanda (Brunel University, London) began the event with a presentation entitled Emerging and priority pollutants – the need for ultra-low trace level monitoring. He explained that water is under threat from our increasing use of chemicals and the rapid urbanisation of our cities. Rakesh’s research interests cover a range of topics related to the development and application of analytical techniques for the detection of environmental contaminants and for assessing animal and human exposure to compounds in the environment.
The Water Framework Directive (WFD) uses environmental quality standards (EQS) for priority substances and priority hazardous substances as the criteria for the assessment of good chemical status. Robust environmental monitoring is essential for assessing the chemical status of water bodies. Data reported to the European Commission show that 40% of surface water resources in the European Union have an unknown chemical status, with many member states not monitoring priority substances. Reasons for the lack of monitoring include the analytical difficulties in detecting and quantifying analytes near the limit of detection, and, in general, the financial costs of ultra-low analytical measurements.
Rakesh Kanda (Brunel University, London) began the event with a presentation entitled Emerging and priority pollutants – the need for ultra-low trace level monitoring. He explained that water is under threat from our increasing use of chemicals and the rapid urbanisation of our cities. Rakesh’s research interests cover a range of topics related to the development and application of analytical techniques for the detection of environmental contaminants and for assessing animal and human exposure to compounds in the environment.
The Water Framework Directive (WFD) uses environmental quality standards (EQS) for priority substances and priority hazardous substances as the criteria for the assessment of good chemical status. Robust environmental monitoring is essential for assessing the chemical status of water bodies. Data reported to the European Commission show that 40% of surface water resources in the European Union have an unknown chemical status, with many member states not monitoring priority substances. Reasons for the lack of monitoring include the analytical difficulties in detecting and quantifying analytes near the limit of detection, and, in general, the financial costs of ultra-low analytical measurements.
Graham Mills (Portsmouth University) and Anthony Gravell (Natural Resources Wales) gave a presentation entitled Comparison of active and passive sampling in relation to contaminants of emerging concern. They discussed sampling practices undertaken at surface water bodies for the purposes of obtaining water samples for chemical analysis and understanding contaminant concentrations. Research interests include the use of gas chromatography and mass spectrometry techniques in biomedical and environmental analyses as well as development of novel sample preparation methods in analytical chemistry and the use of high-field NMR in environmental toxicology. Graham is also very interested in the development of passive sampling devices to monitor water quality and the fate of pharmaceutical residues in the aquatic environment.
The next presentation, by Dr Maria Romero-Gonzalez (University of Sheffield) and Dr Peter Skipworth (Environmental Monitoring Solutions Ltd), was entitled Measuring continuous concentration of mass pollutants in the aquatic environment. The speakers reported on their work using surface-sensitive spectroscopic techniques to elucidate chemical bonding and mechanisms at the solid-water interface, as well as potentiometric methods and wet chemistry studies to quantify thermodynamic and kinetic models of reactive processes in model systems. They discussed the development and intended application of a continuous water monitoring instrument called MultiMEMS, which can detect phosphates, nitrates and metaldehyde in water bodies.
Marianne Stuart (British Geological Survey, Wallingford) spoke about Emerging contaminants in groundwater in urban environments. Her research interests include emerging contaminants and the impacts of hydraulic fracturing. Marianne highlighted the increasing detection of micro-organic compounds in the groundwater environment as advances in analytical techniques are leading to lower detection limits. These compounds include pharmaceuticals and personal care products, lifestyle compounds (nicotine, caffeine) and food additives and their metabolites. Sources in the urban environment include sewage treatment effluent and landfill site leakage. Marianne reported on groundwater monitoring studies in the Sherwood Sandstone aquifer at a site in Doncaster and another in Nottingham, which indicated that emerging contaminants are present at significant depth (>50 m) and that wastewater was the likely source.
A presentation by Barbara Kasprzyk-Hordern (University of Bath), entitled Stereochemistry of pharmacologically active compounds: a new paradigm in environmental analysis and risk assessment, focussed on the significance of chiral organic contaminants such as pharmaceuticals in the environment. Chiral pharmacologically active compounds (PACs) enter the environment mainly through sewage, waste effluents from manufacturing processes, runoff and sludge. They are bioactive, ubiquitous and persistent, with synergistic properties. Considerations of the environmental fate and effects of these substances do not often take into consideration that the enantiomers of the same substance can have different effects. Barbara presented results from the monitoring of several wastewater treatment plants and receiving waters and considered the implications of enantiomer-dependant fate and ecotoxicity of PACs.
The next presentation, by Dr Maria Romero-Gonzalez (University of Sheffield) and Dr Peter Skipworth (Environmental Monitoring Solutions Ltd), was entitled Measuring continuous concentration of mass pollutants in the aquatic environment. The speakers reported on their work using surface-sensitive spectroscopic techniques to elucidate chemical bonding and mechanisms at the solid-water interface, as well as potentiometric methods and wet chemistry studies to quantify thermodynamic and kinetic models of reactive processes in model systems. They discussed the development and intended application of a continuous water monitoring instrument called MultiMEMS, which can detect phosphates, nitrates and metaldehyde in water bodies.
Marianne Stuart (British Geological Survey, Wallingford) spoke about Emerging contaminants in groundwater in urban environments. Her research interests include emerging contaminants and the impacts of hydraulic fracturing. Marianne highlighted the increasing detection of micro-organic compounds in the groundwater environment as advances in analytical techniques are leading to lower detection limits. These compounds include pharmaceuticals and personal care products, lifestyle compounds (nicotine, caffeine) and food additives and their metabolites. Sources in the urban environment include sewage treatment effluent and landfill site leakage. Marianne reported on groundwater monitoring studies in the Sherwood Sandstone aquifer at a site in Doncaster and another in Nottingham, which indicated that emerging contaminants are present at significant depth (>50 m) and that wastewater was the likely source.
A presentation by Barbara Kasprzyk-Hordern (University of Bath), entitled Stereochemistry of pharmacologically active compounds: a new paradigm in environmental analysis and risk assessment, focussed on the significance of chiral organic contaminants such as pharmaceuticals in the environment. Chiral pharmacologically active compounds (PACs) enter the environment mainly through sewage, waste effluents from manufacturing processes, runoff and sludge. They are bioactive, ubiquitous and persistent, with synergistic properties. Considerations of the environmental fate and effects of these substances do not often take into consideration that the enantiomers of the same substance can have different effects. Barbara presented results from the monitoring of several wastewater treatment plants and receiving waters and considered the implications of enantiomer-dependant fate and ecotoxicity of PACs.
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Zulin Zhang (James Hutton Institute) spoke about Short- and long-term temporal trend of organic contaminants in soils following single or multiple applications of sewage sludge to pastures. Zulin is interested in investigating environmental chemical behaviour (source, transport and fate), effect and risk assessment of organic contaminants. He is also interested in developing new analytical and monitoring techniques/methods for emerging organic contaminants of different environmental matrices, with an emphasis on compounds that enter the food chain and have an effect on animal and human health.
Christine Switzer (University of Strathclyde) gave a talk on Emerging contaminants in soils: challenges and opportunities from quantification to remediation. Her research interests lie in the areas of contaminant fate, transport, and remediation. Christine is particularly interested in aggressive remediation technologies for contaminated soils and emerging contaminants in the environment such as fire retardants and other micro-pollutants. She discussed the practical issues concerned with detection and quantification, contaminant release, mass transfer, and finally remediation. Simon Parsons (Scottish Water) concluded the symposium with his lecture on Sustainable water treatment. Simon received the RSC’s Sustainable Water Award in 2014. His presentation centred on the priorities for improving drinking water. In particular, he talked about lead removal, reducing disinfection by-products, and removal of colour. He also considered the impact of the current public perception of chemicals in drinking water. He highlighted a number of internationally significant potable (drinking) water quality incidents which resulted from the removal of disinfectants from the treatment process. He drew attention to the usually high drinking water quality throughout the developed world and the methods different countries had used to achieve that. |
View of the lake at Schloss Steinhofel, Brandenburg, Germany. Many water resources in the EU have unknown chemical status. Credit: JFU
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Copies of the presentations from the speakers are available from the WSF and ECG websites (www.rsc.org/wsf and www.rsc.org/ecg).
