Professor Kevin Thomas leads the Environmental Health Toxicology team at QAEHS. He leads and/or contributes to a wide range of national and international programs that focus on understanding environmental fate, behaviour, effects and risks of contaminants of emerging concern (CECs) with the goal of protecting environmental and human health.
Meet the Environmental Toxicology research team.
Plastic is everywhere and when not disposed of properly it can enter the environment, generally through waste, and then continually fragments until ‘microplastics’ are created. Micro and nano plastics are very small pieces of plastic that are not biodegradable, and could ultimately create risks in the environment and the human body, which are yet to be discovered.
Microplastics have been detected in seafood and a range of other food items, including rice, beer, honey, sugar, salt and mineral water. The primary routes of human exposure to micro and nano-sized plastics are likely to be the consumption of food and drink and inhalation. In order to develop adequate controls to reduce human exposure through ingestion, it is imperative to understand the sources of microplastics and how they are introduced during the food production chain.
The Minderoo Centre - Plastics and Human Health enables world-leading research, including developing methods to accurately sample and measure plastic chemicals and particles in humans, and in particular, human brains.
Current Research Projects
Developing protocols to measure plastic chemicals in human brain, blood and urine
Microplastics: long-term effects of plastic additive chemicals on marine organisms
Fate and impact of past, present and future consumer plastic on soil
Current HDR Student Projects
Assessing Dietary Exposure to Microplastics
Removal of Micro and Nano Plastics from Waters by Foam Fractionation and Froth Floatation
Investigating Mother-Infant Plastics Exposure
Environmental Fate of Microplastics and Tyre Wear Particles in the Environment
Human Exposure and Fate of Micro and Nanoplastics
Identifying Baby Food Pouch Migrants and Evaluating their Potential Risk
Human Exposure and Accumulation of Plastics
Completed Projects
Microplastic Pollution: Nanoscale Surface Interactions and Public Perceptions
Antimicrobial resistance (AMR) is a designated ‘global health emergency’ and although antimicrobial-resistant bacteria and their genes occur naturally in the environment, the phenomenon of rapidly increasing AMR is an entirely manmade crisis which threatens human, animal and environmental health.
AMR occurs when bacteria, viruses, fungi, and parasites resist the effects of medications, making common infections harder to treat and increasing the risk of disease spread, severe illness and death.
Wastewater treatment plants are increasingly seen as ‘hotspots’ of AMR propagation and transfer, and wastewater products (biosolids and recycled water) are known to contain resistant organisms and resistance genes; however, the Australian water industry is unclear about the nature and level of AMR risks associated with their activities and products. Similarly, the follow-on implications of AMR in water and wastewater products for end-users (e.g. in food and agriculture) remain largely untested and unknown.
Such uncertainty is unacceptable and accordingly, the industry needs further information to assess and manage AMR-associated risks to its operations and customers, and regulators need robust data, information and decision-making frameworks/protocols to guide future strategies for mitigating AMR transmission and associated risks to human and environmental health.
Current Research Projects
A National Wastewater Surveillance Program for Antimicrobial Resistance
Current HDR Student Projects
Antimicrobial Resistance Genes in the Atmospheric Environment
Antimicrobials and Other Chemicals that Select for Resistance
The Suitability of Wastewater-based Epidemiology for Antimicrobial Resistance Surveillance
Completed Projects
The Characterisation of Antimicrobial Resistance in Australian Wastewater
Wastewater is known to contain the accumulated biomarkers of human metabolism that directly reflects the exposure and stressors placed upon all those in a contributing community.
Quantitatively measuring specific biomarkers in wastewater collated from defined communities allows the averaged patterns of chemical exposure to be evaluated with the potential to provide excellent spatial and temporal coverage. An important, well recognised issue associated with the use of a wastewater-based exposure monitoring approach is that the level measured in the wastewater may not directly reflect population exposure for certain chemicals. To date no direct link has been made between population-based human biomonitoring and population-based wastewater studies.
Wastewater analysis is an alternative approach for monitoring the population level consumption of a substance based on the analysis of residues of the substance or its metabolite(s) in urine that is pooled in influent wastewater. Wastewater analysis has the advantage of being cost-effective and capable of high resolution temporal and geographic sampling compared with conventional epidemiological methods. Quantitative estimation of the use of a particular type of drug or product is dependent on both the measurement of a biomarker specific to the drug or product, as well as knowing the percentage of that biomarker excreted following human consumption when compared to the quantity consumed.
A recent example of a highly successful application of wastewater analysis to estimate substance use is the National Wastewater Drug Monitoring Program (NWDMP). This program is funded by the Australian Criminal Intelligence Commission, which provides reliable data to inform policy and shape local responses to drug supply and demand. The NWDMP, performed in collaboration with QAEHS researchers, has regularly reported the level of substance use in >50% of the Australian population each quarter since 2016. In Australia, in addition to the NWDMP, our group has also used wastewater analysis to estimate spatial and temporal trends of nicotine use in different communities across the country.
Current Research Projects
Estimating the Use of Tobacco and Nicotine Products through Wastewater Analysis
Revolutionizing Real-Time Genomic Epidemiology in Urban Wastewater Systems
Exposure mapping – combining wastewater analysis with human biomonitoring
National Wastewater Drug Monitoring Program
Improved monitoring of aquatic pollutants in national water resources
Completed Projects
Wastewater Analysis for the Detection of World Anti-Doping Agency (WADA) Prohibited Substances
Innovative Sampling Strategies for Improved Wastewater-based Epidemiology
The Australian population is exposed to a multitude of chemicals that include environmental pollutants such as pesticides, flame retardants, per-fluorinated chemicals, personal care products and metals. Some of these may be associated with adverse health effects in highly exposed and/or vulnerable subgroups. Exposure to these chemicals in the general or specific populations (or individuals) may be determined by the collection and analysis of blood serum and/ or urine; commonly referred to as human biomonitoring (HBM). HBM data have become crucial tools for government policy makers in the legislation and regulation of chemicals.
One of the key challenges in the environmental and exposure sciences is to establish experimental evidence of the role of chemical exposure in human and environmental systems. Non-target analysis employing high-resolution mass spectrometry (HRMS) has been established over the past years as one of the key approaches for tackling this complexity and allows for the retrospective screening of previously archived HRMS data. The sharing and community curation of HRMS data allows the potential to globally collaborate and share data through an online platform in order to optimise the way emerging chemical threats are identified.
The archiving of HRMS data also allows for data to be processed retrospectively, for example to investigate the occurrence of a newly identified compound or simply one that was not considered at the time of analysis. This has even led to proposals for the establishment of data repositories, akin to environmental data banks, where digital information can be safely stored for future retrospective analysis. As far as we are aware there have not been any coordinated studies to investigate the spatial and temporal distribution of contaminants of emerging concern (CECs) in environmental samples through performing retrospective analysis on HRMS data acquired using different instrumental platforms and data processing software.
Current Research Projects
A Global Platform for Identifying Emerging Chemical Threats
Novel Testing Strategies for Endocrine Disruptors in the Context of Developmental Neuro Toxicity
Per- and poly-fluoroalkyl substances (PFAS) are a large group of chemicals commonly used since the 1950s in a range of consumer and industrial applications. Due to their properties and widespread use, PFAS are environmentally ubiquitous and frequently detected in humans worldwide. The Organisation for Economic Co-operation and Development (OECD) has identified to date >4,700 PFAS in use globally. Ninety percent of these have been identified as potential precursors to specific PFASs that bioaccumulate in humans (e.g. perfluoroalkyl acids, PFAAs). Transformation of PFAS precursors in the environment, or their metabolism in humans, leads to indirect exposure pathways for the same bioaccumulative PFAS.
Despite the high number of PFAS known to be in use, targeted biomonitoring typically targets only a limited number of ~30 analytes using tandem mass spectrometry (LC-MS/MS). In Australia, 26 PFAS have been detected in human serum including four previously unreported compounds. Notably, current biomonitoring programs exclude most known precursors and have been slow to add new fluorinated compounds substituted by industry to replace those phased out of production.
In addition to the routinely monitored PFAS, 1,031 other PFAS were recently reported to occur in the environment, discovered using nontarget high-resolution mass spectrometry (HRMS) techniques. Australians, and others elsewhere in the world, are therefore undoubtedly exposed to more PFAS compounds than those typically measured in human biomonitoring programs, either directly or through the transformation of precursors. Understanding of the PFAS exposome, i.e. the totality of human environmental exposures to PFAS, is therefore limited amongst scientists and stakeholders such as exposed individuals, the wider general public and public health regulators.
Current HDR Student Projects
Detecting Per-and-Polyfluoroalkyl Substances from Unidentified Chemical Compounds
PFAS Identification Algorithm from Mass and Fragmentation Data