Assessing & Managing Real Life Risks from Chemical Mixtures

17 November 2017 09:15-16:00, London, United Kingdom

Humans and wildlife are exposed to hundreds of chemicals at varying doses every day, for example in the air we breathe, the water we drink, the food we eat and from the consumer products we use. Typically, we assess the risks of chemicals by considering exposure to individual chemicals and their effects. In reality, organisms are exposed to many chemicals simultaneously and sometimes chronically or frequently over long durations. Some would say that the existing system to assess the risks of individual chemicals is adequate to protect us from our exposures to different chemicals simultaneously, so long as exposure of each chemical is controlled below a certain dose. Others argue that when exposed to multiple chemicals, their combined action on the body as a whole can lead to harmful effects that are not evaluated by the current methods.  Examples of adverse outcomes in humans are an increased risk of reproductive effects, metabolic and endocrine disorders such as diabetes, or increased incidence of cancer. Chemical mixtures in the environment can also adversely affect ecological species such as fish, birds and mammals, in terms of their normal reproduction, growth and population numbers.

There are many questions for the scientific research community to answer that will aid the development of more effective policy and regulation. These include questions around monitoring and measurement methods – are current methods effective or are there improvements to be made. The modelling of source-pathway-receptor exposure routes is often uncertain, for example as to how chemicals travel from air, water and soil and into the body, and at what concentrations. Many assumptions are made – can these be refined by better measurement? Other questions are around how to identify and characterise adverse effects that may be caused, ameliorated or exacerbated by the presence of multiple chemicals in the body simultaneously. Is there an increased risk of adversity that we are not adequately addressing by current policy and regulation, or is the current system of risk assessment and risk management adequate for health protection goals? Chemistry is relevant to all of these questions, and we will ask what should be the focus of future chemical sciences research to provide the right types of evidence to inform policy and decision making.


In this symposium, we shall consider the following questions:
  1. What are the gaps in our knowledge as to the sources and quantities of the (potentially hazardous) chemicals present in air, soil, water, food and consumer products?
  2. What are the gaps in our knowledge as to how living systems are exposed and affected by multiple and simultaneous chemical exposures at the chemical & biological interface?
  3. How can we assess the real level of risk from multiple and simultaneous exposures to hazardous chemicals via multi-causal perturbations of  biology in humans & wildlife?
  4. How can the chemical science community perform research and generate fit-for-purpose evidence to enable policy and chemicals regulation to be developed for chemical mixtures (that aims to adequately protect public health & the environment whilst at the same time realises the beneficial use of chemicals for society)?
For the purposes of this symposium, ‘chemical mixtures’ are:
  • Substances that are mixtures themselves according to ECHA definitions within REACH (i.e. multi-constituent substances (MCS); materials of unknown or variable composition, complex reaction products or biological materials (UVCB))
  • Products that contain more than one chemical, e.g. cosmetics, biocidal or plant protection products
  • Chemicals jointly emitted from production sites, during transport processes, and consumption or recycling processes
  • Several chemicals that might occur together in environmental media (water, soil, air), food items, biota and human tissues, as a result of emission from various sources, via multiple pathways. 


Early Bird
(By 9 October 2017)
(By 6 November 2017)
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Non Members £85 £100
Student Members £45 £65
Student Non Member £60 £80
The Royal Society of Chemistry

The Royal Society of Chemistry, Burlington House, Piccadilly, London, W1J 0BA, United Kingdom

Professor Paul Leinster, University of Cranfield, United Kingdom

Professor Paul Leinster CBE is Professor of Environmental Assessment at Cranfield University. Prior to joining Cranfield he was Chief Executive of the Environment Agency from June 2008 to September 2015. He is a member of the government’s Natural Capital Committee, a Non-Executive Director of Flood Re, a Non-Executive Director of Delphic HSE a toxicology consultancy, Chair of the Bedfordshire Local Nature Partnership and a board member of the Institute of Environmental Management and Assessment. Prior to joining the Environment Agency in 1998 Paul worked in the private sector for over 20 years including for BP, SmithKline Beecham and Schering Agrochemicals including on the assessment and control of exposures to chemicals in the workplace and the general environment.  

Professor Juliette Legler, Brunel University, United Kingdom

Juliette Legler is Professor of Toxicology and Environmental Health at the College of Health and Life Sciences, Brunel University London. She is Leader of the Environment and Health Theme, a multidisciplinary group of researchers within Brunel University’s Institute for Environment, Health and Societies. Prior to joining Brunel University London in January 2016, she was employed at the Institute for Environmental Studies, VU University Amsterdam, where she was Deputy Head of the Department of Chemistry and Biology. From 2014-2015 she also served as Director of the SENSE Research School for Socio-Economic and Natural Sciences of the Environment, a joint venture of the environmental research institutes of ten Dutch universities. Prof. Legler is a European Registered Toxicologist and served as Vice President of the Netherlands Society of Toxicology from 2015-2016. Her research focusses on the molecular mechanisms of toxicity of endocrine disrupting chemicals and the effects of exposures on the health of humans and wildlife. 

Professor Alastair Lewis, University of York, United Kingdom

Alastair Lewis is professor of atmospheric chemistry at the University of York and Science Director at the National Centre for Atmospheric Science. His specialism is in atmospheric chemistry where he has worked on the development of novel instrumentation and sensors to study pollution and emissions and in 2013 led the establishment of the Wolfson Atmospheric Chemistry Laboratories, a joint research initiative of the University of York, NCAS and The Wolfson Foundation.   He has participated in > 25 major air pollution field projects from the polar regions to city centres, open oceans to tropical forests and is currently leading a major UK-China collaborative project studying air pollution processes in Beijing, bringing together 15 UK and Chinese research institutions. He has received several awards for his research including a Philip Leverhulme Prize, the 2012 Royal Society of Chemistry Award for Environment, Energy and Sustainability and their SAC Silver Medal for analytical science. He was listed in 2016 as one of the world’s 100 most influential analytical scientists.   He has written more than 240 peer-reviewed articles and book chapters and has been a member of a number of international science advisory boards including with Defra, WMO and UNEP.

Dr Ovnair Sepai, Public Health England, United Kingdom

Ovnair Sepai has worked in academia and the public sector as an analytical chemist and toxicologist since completing her PhD at Royal Holloway College, London University in 1989.  Her first post doc was with the UK Medical Research Council toxicology Unit where she developed her skills in human biomonitoring in relation to assessing population exposures to chemicals and risk assessment.  This lead to a second post-doc at the Institute for Pharmacology and Toxicology in Wurzburg, Germany.  In 1994 Ovnair moved to Newcastle University to become a course director for a Master’s degree and to continue her interests in human biomonitoring.  At Newcastle University Ovnair gained a post graduate certificate in business management.  From 2000 till 2002 Ovnair worked as an education volunteer and course facilitator for VSO (Voluntary Services Overseas) in Ethiopia.   Ovnair’s career after returning to the UK moved from academia to the Public sector working for the Health Protection Agency which was formed in 2003.  She worked her way up to Group Leader at the Centre for Radiation, Chemical and Environmental hazards (CRCE) now part of Public Health England.  Ovnair leads a team of 8 Toxicologists who’s remit spans from providing advice on the health impacts of chemicals to Government to delivering training to Master’s degree students in Public Health.  Ovnair has lead workshops and events for her group as well as for research projects.  Ovnair leads for PHE on a Pan-European project HBM4EU ( ) – which requires both scientific and leadership skills.  Ovnair is a Fellow of the Royal Society of Chemistry.   Ovnair volunteers at a local music school where her daughter learns the Oboe and Recorder.  She also has two grownup step daughters.  Ovnair is learning Spanish and music theory – just for the fun of it.

Dr Miranda Loh, The Institute of Occupational Medicine (IOM) , United Kingdom

Miranda is a Senior Scientist working in the Centre for Human Exposure Science of the Research Division at the Institute of Occupational Medicine.  She is an exposure scientist who tries to understand how people interact with their environment, and how this affects their exposure to both negative and positive aspects of the environment.   She has been involved in evaluating air pollution and physical activity sensors and is using a multi-stressor indoor and personal exposure assessment system, including sensor technology, that can be used in exposome studies as part of the Health and Environment-wide Associations based on Large Population Surveys (HEALS) study, funded by the European Union.  Her work on environmental health extends also to Asia, as the Principal Investigator for the Air Pollution Impacts on Cardiopulmonary disease in Beijing: An integrated study of Exposure Science, Toxicogenomics & Environmental Epidemiology (APIC-ESTEE) funded by the British Natural Environment Research Council, the Medical Research Council, and China’s National Natural Science Foundation.  She is also involved in air pollution exposure and health projects in India and Thailand. Past projects include assessment of metals exposures of children living near a hazardous waste site in a former mining community and measurement and modelling of exposures and risk to volatile organic compounds.

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