Environmental exposure: the concept of exposome, its applications and public health issues

The estrogen distilbene causes cancer and endometriosis in pregnant women; diet and sedentary lifestyle contribute to the obesity epidemic; tobacco is the leading cause of lung cancer; allergens and chemical pollutants cause the development of asthma; endocrine disruptors are responsible for reduced fertility and developmental delays in children.
74% of deaths in the world are caused by chronic diseases, considered by the WHO as an epidemic (cardiovascular diseases, cancers, respiratory diseases, diabetes…). The cause of these diseases is a combination of multiple genetic and non-genetic factors to which we are exposed. While the genetic factors are known, the non-genetic ones are not. Yet one in four deaths is caused by environmental factors, and one in six specifically by chemical pollution, according to the WHO. In this article, Alcimed is interested in this problem and in the concept of exposome, investigating the promises and the new angles of innovation that it opens.

What is the exposome?

Professor Christopher Paul Wild introduced the exposome concept in 2005 as “the totality of exposures to which an individual is subjected from conception to death. It is a complex and dynamic representation of the exposures to which a person is subject throughout his or her life, integrating the chemical, microbiological, physical, recreational, and drug environments, lifestyle, diet, and infections.

The exposome consists of 3 components:

• Internal exposures, which include exogenous molecules present in humans as well as their transformation products, such as hormones, inflammatory stress markers and metabolites.
• Specific external exposures, including chemical and environmental pollutants, diet, tobacco and drugs.
• General external exposures, including social, economic and psychological factors, as well as climate.

The exposome: a public health concern and major public research initiatives in Europe

While the genome has been extensively studied in recent decades, leading to precise knowledge of the genetic determinants of many diseases and opening the door to new treatments such as gene therapy, public policies are now progressively integrating the notion of the exposome into research programs and public health concerns. These studies may lead to better prevention of chronic diseases, via an adaptation of regulations related to marketed chemical substances and environmental restrictions and recommendations.

The characterization of the different components of the exposome, their interaction and the measurement of their effect on the appearance of human diseases are the current challenges of the research teams working on this subject. At the European level, the European Human Exposome Network encompasses 9 projects in 24 countries from 2020 to 2025, with Horizon 2020 funding exceeding 100 million euros. In France, Inserm has founded “France Exposome”, a research infrastructure aimed at structuring and energizing the scientific community working in this field. In addition, the University of Montpellier is launching this year, in collaboration with many partners (including CNRS, Inserm, the Montpellier University Hospital and the Occitanie Region) a call for projects to establish an institute for research and training on the exposome, named ExposUM.

What are the benefits of exposome?

Exposome and the emergence of environmental intelligence

In addition, companies that develop environmental intelligence products and services, by combining environmental measurements, connected objects and modeling, aim to give the population a better understanding of the effects of the exposome on human health and a better control of exposure.

Companies such as BreezoMeter or Meersens have developed solutions for analyzing environmental factors such as air or water quality, pollen levels, waves, solar radiation, noise, etc. In short, data are aggregated to measure all the environmental exposures to which people are subjected and which are likely to have an effect on their health.

These services are intended not only for individual users, but also for companies and public organizations as part of their CSR policy or for the design of smart cities. Some pharmaceutical companies use them to monitor the impact of exposure on human health.

The exposome concept applied to the cosmetics industry

The cosmetics industry is a pioneer in the application of the exposome concept to products and services for the general public. Healthy skin acts as a barrier between the outside world and the inside of our body; it is the first to be impacted by the exposome. UV rays, pollution, poor nutrition and lack of sleep contribute to skin aging.

At the same time, climatic changes, psychological stress and hormonal variations alter the function of the skin barrier. Solutions are developed at different levels, from exposure to protection:

• L’Oréal is collaborating with BreezoMeter, a leader in “climate tech” with an innovative environmental information platform, to reveal the links between environmental exposures and skin aging.
• Vichy (L’Oréal) has developed SkinConsultAI.com, a personalized diagnostic technology based on AI to detect signs of skin ageing, resulting from various exposures, and propose specific skincare protocols.
• Microphyt, proposes Renouvellance, a biomimetic ingredient derived from microalgae to fight against the combined effect of UV rays and pollution on the skin.

The exposome at the heart of the prevention and treatment of chronic diseases

The ultimate goal of these studies is to enable the development of personalized diagnostics and treatments, in the same way that the study of the genome has led to gene therapies.

Other sectors, such as health, are applying the exposome concept to their research and innovations. The prevention of chronic diseases is at the heart of these applications, notably through the environmental intelligence services mentioned above. In addition, the development of precision medicine to diagnose and treat complex diseases, the origin of which is linked to the exposome, is a major ambition of the sector. LinusBio has characterized biological pathways and mechanisms involved in some of these chronic diseases, such as autism, schizophrenia and Lou-Gehrig’s disease.

These studies have led to the definition of exposome biomarkers for these chronic diseases. An important advance was the development of the first diagnostic device for autism, StrandDxTM-ASD, which allows the detection of exposomic molecular biomarkers from a hair. The ultimate goal of these studies is to enable the development of personalized diagnostics and treatments, in the same way that the study of the genome has led to gene therapies.

Learn more about personalized medicine >

Challenges to overcome in order to achieve the great promises expected

The study of the exposome represents an infinite number of variables, including all the non-genetic environmental factors to which each individual is exposed in a dynamic way throughout life. Important challenges must therefore be overcome to reach a characterization of the exposome as it now exists for the genome:

• The quantity and diversity of exposures and their spatiotemporal variation. The mapping of the complete exposome is extremely laborious, and will require the combined use of different high-throughput analytical methods, the design of new standards and the consideration of synergistic effects between different exposures.
• Big data management. The collection, aggregation and analysis of the large amounts of data produced by all these measurement methods is one of the major challenges of exposome analysis.
• The temporality of the studies required. Causal links between exposures and diseases have already been established, but the cumulative and combined effect of many exposures remains largely unknown, due to the novelty of this research topic and the need for time to conduct long-term studies on the subject.

We have known for years that many diseases are not hereditary, but caused and triggered by our environment and all the exposures we face. In this context, the study of the exposome makes it possible to define non-genetic biomarkers for chronic diseases and to characterize avenues for both their prevention and the development of new treatments.

Our teams at Alcimed are passionate about this subject, which is why we help our customers, whether they are pharmaceutical leaders or chemical manufacturers, to better understand the associated issues! Don’t hesitate to contact our team!

About the author, 

Ana, Consultant in the Alcimed’s Life Sciences team in France