What does the concept of exposome bring to the understanding of chronic diseases?
Prof. Robert Barouki, Professor at the University of Paris, Unit Director at Inserm, Chairman of the Exposome Working Group at ANSES
If we take the example of cancer, the genetic causes are now relatively well known. But as far as non-genetic factors are concerned, this is still very vague! For the first time, the concept of exposome makes it possible to study all the exposures to which an individual is exposed throughout his life. The temporal dimension associated with multiple exposures provides an overview of the causes of these diseases. How to translate it concretely into research? Different approaches, research projects and cohort studies are carried out around the world. All of this work makes it possible to document and model exposure to several hazards, whether chemical, biological, physical, psycho-social and according to different environments, for example urban, rural or work. It goes far beyond the combined effects of different chemicals.
Indeed, it is a question of knowing the interactions between various types of factors, such as the food imbalance and the contamination of food by chemical substances or the socio-economic situation of the populations and these same exposures. The exposome also highlights the consideration of more sensitive or vulnerable populations, for example unborn children and babies, but also disadvantaged populations. The temporal aspect of the exposome is one of the most difficult to study. How to explain that an exposure at a time T will have effects much later in our life?
“The challenge is to understand how an exposure at a time T will have effects much later in our life”
The solution to this challenge will undoubtedly come from epigenetics. These are modifications of the molecular environment of genes, without any change in sequence. These epigenetic modifications are relatively stable, heritable from one cell to another and influence gene expression. They can appear following a stress, remain present a long time followingwards and are expressed according to the physiological state of the organism, sometimes years or decades later.
Beyond research, it is important that health safety agencies like ANSES continue to address these issues. The challenge is to be able to know which exposures have the greatest impact on our long-term health and to act accordingly to prevent these diseases. ANSES’s Exposome working group is one of the first to attempt to take this concept into account in the assessment of health risks.
What research on the exposome is funded by ANSES?
Laetitia Dubois, Director of Research Funding and Scientific Watch
With the PNR EST (National Environment-Health-Work Research Programme), we finance research projects every year to better understand exposures in our daily environment and their effects on health. We address, for example, issues of air quality, chemical substances present in our environment and in consumer products, radio frequencies and 5G, or occupational health, etc. The data and knowledge resulting from this research must be directly usable to assess risks and support management measures. The study of the exposome is a vast subject, it requires the financing of research projects which will provide data which will make it possible to know it better. To study the cumulative effects of several stressors and their interactions, it is also important to properly document the effects of each factor alone. The introduction of the concept of exposome makes it possible to emphasize where there is a particular lack of data concerning less known effects such as, for example, the impacts of co-exposures to microbiological and chemical agents on human health.
“Introducing the exposome concept helps to focus where data on lesser-known effects is particularly lacking. »
To really document the exposome, it is necessary to study the impacts of multiple exposures and the interactions between the different types of chemical, physical, biological nuisances or even stress, organizational constraints in the professional environment and socio-economic conditions. It is also necessary to know the windows of exposure, that is to say the moments in life when we are most vulnerable. For example, concerning bisphenol A, we were able to determine that infants were more sensitive to the effects of this substance. The theme of endocrine disruptors is also one of the subjects particularly targeted during our calls for projects. Since 2011, it is estimated that nearly half of the projects funded have provided knowledge on the exposome.
Our latest call for projects emphasizes the importance of research on this question of the exposome. The objective is that in the long term we can put together all these research results. This will make it possible to make the link between multiple exposures, diseases and times of life when we would be at greater risk. Today more than ever, in an increasingly polluted environment and rapid technological developments, it is essential to strengthen research funding. We must be able to give ourselves the means so that science advances with our society.
What are the objectives of the Exposome working group?
Dr. Amélie Crépet, scientific project manager at the Risk Assessment Department
This working group (WG) aims to strengthen the integration of the exposome into ANSES’s expert appraisal work. The idea is to help the Agency make a gradual change in the treatment of the health questions it is asked, by proposing a global and temporal approach to exposures and risks. The exposome contains so many components that you have to be able to understand them step by step.
“The WG helps us to make a step change in dealing with health issues”
To do this, the WG is working to propose more or less long-term actions to ANSES to raise the awareness of expert committees and gradually introduce the various components of the exposome into the expert appraisals, such as multi-source, multi- substances, multi-hazards, which depend on lifestyle habits and the urban/rural and social environment, etc. In this context, it recommends the development of operational methods and tools as well as the generation of the necessary data. He also proposed questions to be investigated in the context of PNR EST research. Of course, it starts from what ANSES is already doing in terms of exposome.
In addition, the WG is working on making concrete proposals to better address issues related to the exposome in its ongoing expert appraisal work. For example, the Agency is currently working on the issue of risks for workers involved in household waste collection, sorting and processing activities. These people are affected by the risks associated with chemical substances, biological agents and they carry out activities that are often physically demanding. A reflection on the psychological, biological and socio-economic factors that determine the mental health of these professionals will be integrated.
Another example concerns the effects of digital tools on the health of children and adolescents. This expertise will attempt to assess the effects on physical and mental health by integrating the behavioral, socio-economic and family dimensions. In an “exposome” approach, it is planned to analyze the way in which everyday chemical and microbiological substances, particularly found in homes, can also contribute to the occurrence of disorders associated with the use of digital tools.
This multidisciplinary working group, made up of external scientific experts and ANSES coordinators, brings together risk assessors, toxicologists, microbiologists, epidemiologists, chemists/analysts, statisticians, sociologists, economists, etc.
