The principal research interests of our group fall into the three interrelated research areas of environmental, analytical and water sciences. We work in the area of water quality and novel technologies used to decrease contamination of water. Our recent interests focus on water fingerprinting to inform the state of the environment and public health.
Emerging micropollutants in the environment
Emerging environmental contaminants including pharmaceuticals, illicit drugs, personal care products and endocrine disruptors are a group of compounds without well understood occurrence, fate and effects in the environment and human health but with the potential to cause such effects. Our research concentrates on identifying new micropollutants in environmental matrices, understanding their fate in the environment and identifying their possible effects on humans and the environment. This includes the development of new analytical methodology primarily utilising liquid chromatography coupled with mass spectrometry to identify and quantify micropollutants and their transformation products at low ppt levels.
The enantiomers of chiral compounds can differ in interactions with chiral environments such as enzymes in the body. Therefore in biological systems they can be recognised as two different substances that elicit different responses: one enantiomer of the same drug may produce the desired therapeutic activity, while the other may be inactive or even toxic. The ratio of active/inactive enantiomer of the chiral drug can change significantly after its administration, metabolism in and excretion from the body. It can be subsequently altered during biological wastewater treatment and when the drug is already present in the environment. Biological processes can lead to stereoselective enrichment or depletion of enantiomeric composition of chiral drugs. Therefore the very same drug might reveal different activity and toxicity and this will depend on its origin and exposure to several factors governing its fate in the environment.
Existing reports on the presence and fate of pharmacologically active compounds, due to their non-enantioselective analysis, do not tackle the problem of their chirality. As a result, current understanding of environmental fate and effects of chiral drugs is limited, might be inaccurate and misleading, as it incorrectly assumes that enantiomers have identical environmental behaviour and toxicity. Therefore to understand and predict the mechanisms governing the fate of chiral drugs, their possible toxicity and impact on the environment, determination of enantiomeric composition of chiral drugs in environmental matrices is essential and constitutes a vital part of our research. This involves also the development of analytical methods capable of enantiomeric separation of chiral drugs and their application in environmental context.
Antimicrobials and antimicrobial resistance
Rapid assessment of public health is essential for the prevention, control or mitigation of exposure risks (e.g. to chemical contaminants or pathogenic organisms) and for improving health. There is growing, albeit still limited, evidence of cause – effect association between man-made chemicals present in industrial and household products, often leaching into the environment, and public health outcomes. These include poor air quality linked with higher prevalence of asthma in urban populations, and presence of endocrine disrupting chemicals in household products linked with diabetics or infertility. Strategies to control and regulate anthropogenic chemicals are limited due to gaps in evidence resulting from limited risk assessment methods. More efficient approaches are needed to identify cause-effect linkages between the environment and human health. Attempts to link environmental stressors with health effects are currently undertaken via molecular epidemiology and human biomonitoring. However, the limitations of molecular epidemiology, due to logistical difficulties and high cost, are the restricted size of study groups and inability to gather comprehensive information on combined spatiotemporal exposure to mixtures of stressors and their effects. There is therefore a need for an evidence-based public health diagnostics and risk prediction system, which will collate long-term comprehensive, spatiotemporal datasets on public health status and trigger rapid response from regulatory and public health sectors with the aim of disease prevention and environmental health promotion. This system, if operated in real-time and if linked with timely response systems, could allow public health threats to be rapidly identified, at low cost, and instantly dealt with, reducing the global burden on public health. Wastewater fingerprinting or wastewater-based epidemiology provides a timely solution.
Wastewater-Based Epidemiology (WBE) currently informs worldwide illicit drug use trends. WBE has also been applied to estimate public exposure to lifestyle chemicals, pharmaceuticals, industrial chemicals, household contaminants as well as food contaminants. WBE has revolutionised population health studies, especially in the context of the COVID pandemics.
Our research focusses on the development and application of WBE tools with an aim of building early warning systems for environmental and public health. We are currently focussing on biochemical mining of wastewater for markers of community-wide intake of wide-ranging harmful chemicals, pathogenic organisms as well as resulting effects.
Catalytic ozonation in water treatment
Ozone, due to its high oxidation and disinfection potential, has received much attention in water treatment technology. It is applied in order to improve taste and colour as well as to remove the organic and inorganic compounds in water. Despite the several advantages of using ozone, it has a few disadvantages which limit its application. The main ones are: relatively low solubility and stability in water. Because of both the high cost of ozone production and only partial oxidation of organic compounds present in water, the application of ozonation might not be feasible from an economic point of view. Advanced oxidation processes such as O3/H2O2, UV/O3, UV/H2O2, TiO2/UV, Fenton’s reagents and catalytic ozonation involve the generation of hydroxyl radicals, which are active oxidative species. However, their reactions are not selective and therefore more likely to be hindered by competitive reactions. For that reason, it is also desirable to investigate new methods based on molecular ozone reactions, which allow for both better ozone dissolution and stability in water due to the presence of non-polar materials such as: non-polar fluorinated hydrocarbon solvent or perfluorinated alumina. We focus on investigating the application of metal oxides and zeolites as heterogeneous catalysts for the ozonation of common water micropollutants.
We develop methods utilising primarily chromatographic techniques and mass spectrometry aiming at environmental and epidemiology applications. We are also interested in new approaches to sample preparation.