Imperial College London


Faculty of MedicineSchool of Public Health

Reader in Analytical & Environmental Sciences







Norfolk PlaceSt Mary's Campus





Dr. Leon Barron leads the Emerging Chemical Contaminants team within the Environmental Research Group at Imperial. His research aims to further our understanding of the sources, risks and impacts existing, emerging and new chemical contaminants on environmental and public health. His projects have mainly focussed on pharmaceuticals, personal care products, illicit drugs, pesticides, disinfectant by-products, security-related substances (e.g., CB and E) and industrial chemicals. His work spans across all environmental spheres (soil, water, air and biological materials).

He holds a BSc(Hons) in Analytical Science (2001), a PhD in Analytical Chemistry (2005) and a Postgraduate Certificate in Academic Practice (2011). He pursued his postdoctoral research at Dublin City University, Ireland and at the Norwegian Institute for Water Research developing novel approaches to monitoring environmental contaminants in water and soil. He moved to King's College London as a Lecturer (in 2009) and then Senior Lecturer (in 2015) in Forensic Science. In 2020, he moved to Imperial College London as a Senior Lecturer in Analytical & Environmental Sciences. He has published >90 peer-reviewed articles in the fields of analytical chemistry, environmental pollution, ecotoxicology and forensic science.

He sits on the editorial board of Science & Justice, Journal of the Chartered Society of Forensic Sciences and from 2011-2014 was its Editor in Chief. He regularly acts as a peer-reviewer for several internationally reputed analytical journals. He is a Fellow of the Royal Society of Chemistry, the Chartered Society of Forensic Sciences and the Higher Education Academy. He also is an elected member of the Analytical Sciences Community Council and the Separation Science interest group committee at the Royal Society of Chemistry, as well as the Analytical Chemistry Trust Fund (ACTF).

Key Leadership Roles:

Emerging Chemical Contaminants Team lead within the Environmental Research Group 

Research Interests:

  • Analytical Science: trace environmental analysis with core expertise in  separation science (e.g. LC, IC, GC, IMS and CE), advanced sampling/sample preparation (e.g. including on/offline SPE, passive sampling, pressurised liquid extraction), high and low resolution (tandem) mass spectrometry and data mining/computational modelling (e.g., machine learning and multivariate analysis for large datasets). 
  • Chemical Risk Assessment: He actively researches in understanding the breadth, sources and fate of and as well as phenotypic and molecular level toxicological effects on biota. He is particularly interested in New Approach Methods (NAMs) including novel predictive in silico and in vitro tools for chemical hazard and risk assessment. This includes performing exposure-based and machine-learning enhanced metabolomics and lipidomics to understand molecular-level effects, and mainly in terrestrial and aquatic invertebrates. 
  • Wastewater-Based Epidemiology: Near real-time population-level health assessment through the wastewater analysis. His team has been a member of the Sewage analysis CORE Group since 2011 contributing to knowledge of the health of ~30 countries and 90 cities globally. For example, we have provided data for London annually to the European Monitoring Centre for Drugs & Drug Addiction on illicit drug use in the EU.
  • Early Warning Systems and 'Environmental Forensics': He focuses on identifying chemical or physical evidence that may indicate illegal activity including contact or clandestine manufacturing of illicit substances, chemical pollution or identifying imminent threats to public safety. 

Postgraduate PhD Student Supervision:

Shahid, A Measuring pesticide exposure and microbial-level impacts in soil ecosystems using novel passive sampler devices (EPSRC/ICB funded studentship with Syngenta)

Oloyede, O Measurement and prediction of the biotransformation rate of pharmaceuticals in the aquatic environment (BBSRC/AstraZeneca-funded PhD studentship)

Grant, D Developing cability for opioid misuse monitoring using wastewater-based epidemiology (NHIR-funded PhD studentship with UKHSA under the HPRU in Environmental Exposures and Health)

Ciccarelli, D Non-target analysis of drinking water for highly toxic agents (NIHR-funded PhD studentship, under the HPRU in Chemical and Radiation Threats and Hazards)

Egli, M Population-level monitoring of pharmaceutical use using wastewater-based epidemiology, PhD student

Birkitt, L A machine learning approach to understand how invertebrates maintain homeostasis upon exposure to pharmaceuticals, BBSRC/AstraZeneca funded PhD studentship 

Post-doctoral fellows:

Dr Keng Tiong Ng, Identification of illegal threat manufacturing activity via wastewater markers (ThreatMARK), Royal Academy of Engineering IC Research Fellow 

Dr Helena Rapp-Wright, Wastewater-based epidemiology

Dr Shane Fitzgerald, Low cost passive sampling of VOCs in indoor air (Wellhome project) and analysis using LC-QTOF-MS, GC-MS, comprehensive GCxGC-TOF-MS

Dr Alexandra Richardson  PFAS analysis in UK drinking water (NIHR funded project with UKHSA)

Professional Services staff

Stav Friedman and Chyshanthi Christy, Commercial Projects Manager and Coordinator

Margarita White Research Assistant



Perkins R, Barron L, Glauser G, et al., 2024, Down-the-drain pathways for fipronil and imidacloprid applied as spot-on parasiticides to dogs: Estimating aquatic pollution., Sci Total Environ, Vol:917

Egli M, Rapp Wright H, Oloyede O, et al., 2023, A One-Health environmental risk assessment of contaminants of emerging concern in London’s waterways throughout the SARS-CoV-2 pandemic, Environment International, Vol:180, ISSN:0160-4120

Rapp-Wright H, Rodríguez-Mozaz S, Álvarez-Muñoz D, et al., 2023, International comparison, risk assessment, and prioritisation of 26 endocrine disrupting compounds in three European river catchments in the UK, Ireland, and Spain, Molecules, Vol:28, ISSN:1420-3049, Pages:1-25


Ciccarelli D, Christopher Braddock D, Surman AJ, et al., 2023, Enhanced selectivity for acidic contaminants in drinking water: From suspect screening to toxicity prediction, Journal of Hazardous Materials, Vol:448, ISSN:0304-3894, Pages:1-12

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