Imperial College London


Faculty of MedicineSchool of Public Health

Reader in Analytical & Environmental Sciences







Norfolk PlaceSt Mary's Campus





Dr. Leon Barron received both a BSc in Analytical Science (2001) and a PhD in Analytical Chemistry (2005) from Dublin City University (DCU), Ireland. He then pursued his postdoctoral research for a further four years there 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, where he led the Environmental & Forensic Chemistry group for 11 years. In 2020, he moved to Imperial College London as a Senior Lecturer in Analytical & Environmental Sciences. He has published >75 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 member of the Royal Society of Chemistry, the Chartered Society of Forensic Sciences and a Fellow of the Higher Education Academy. He also sits on the Analytical Division Council and the Separation Science interest group committee of the Royal Society of Chemistry, as well as the London Biological Mass Spectrometry Discussion Group committee.

Key Leadership Roles:

Emerging Chemical Contaminants Team lead within the Environmental Research Group 

The aim of the Emerging Chemical Contaminants team is 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).

Research Interests:

  • Analytical Science: His particular strength lies in trace environmental analysis and has core expertise in the separation sciences (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 Threat Warning 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. With a significant track record in forensic science, he specialises in identifying trace chemical signatures in forensic evidence types such as fingermarks, biological materials, as well as environmental matrices including early detection of explosives and new chemical/biological contaminants and hazards in the environment. He also led a major project on developing fit for purpose technologies for recovering forensic evidence from poached ivory which is now in use in >40 countries globally.

Postgraduate PhD Student Supervision:

Egli, M Population-level viral exposure and associated pharmaceutical treatments by 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 

Richardson, A Using surrogate passive sampler devices and predictive machine learning algorithms to replace invertebrate use in micropollutant bioconcentration testing, BBSRC/Agilent funded PhD studentship 

Irlam, R Solving the impact of sample matrix on trace explosives detection using 3D printed micro-solid phase extraction arrays and high-resolution analysis, EPSRC/Dstl funded PhD studentship 

Rapp-Wright, H Innovative monitoring to prioritise contaminants of emerging concern for Ireland, EPA Ireland funded PhD studentship 

Almekdad, D Standardization Of Laboratory Medicine; The Development And Application Of Isotope Dilution Mass Spectrometry Based Reference Method Procedures For The Analysis Of Immunosuppressant Drugs And Metanephrines In Biological Samples, LGC Funded PhD studentship 

Post-doctoral fellows under Supervision:

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



Barron L, 2023, A One-Health environmental risk assessment of contaminants of emerging concern in London’s waterways throughout the sars-CoV-2 pandemic, Environment International, ISSN:0160-4120

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, 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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