EXPOSOME

A few years ago, one doctor among the scientific community studying environmental factors related to Occupational Medicine and Environmental Toxicology (1) came up with the term and concept of Exposome to refer to all the environmental factors to which we are exposed during the course of life and affect our health.

The term is intended to mimic others associated with the «layers» or biological organizations that also configure the specificity of each individual being, such as the genome, microbiome or epigenome. The Greek suffix (-σῶμα) -soma means body or (-ῶμα) -oma which gives an idea of the whole, biological structure, and the Latin prefix Expo meaning to be exposed.

Assessing the risk of exposure to environmental factors is a difficult endeavor for researchers since during the course of his life, an individual is exposed to thousands of factors, which influence varies as per the exposure time, age, concentration, among some of the variables. This entails a challenge for epidemiologists and generates statistical difficulties since it is not possible to separate each factor individually and to its degree.

On the one hand, there is some evidence that is easy to identify: The Exposome of subjects exposed to radiation by contamination, generates alterations that lead to cancer. Children who collect waste in landfills in developing countries will suffer skin and respiratory problems and cancers due to exposure to toxins, heavy metals and carcinogenic gases. Pollution in large cities causes respiratory and cardiovascular diseases. The Exposome, as it encompasses all the factors to which one can be exposed, ranges from work, family to leisure activities. Living in a city or in the countryside, working in industry or in services, protecting yourself from the sun during vacations or agricultural work, being exposed to occupational hazards, lifestyles… all of this makes up our Exposome.

The Exposome can clearly be transmitted as well. How? In the same way that our lifestyle affects our epigenome, (alterations in our genome that are fixed in new chemical bonds in our genetic code and that are therefore transmitted between generations), nutrition, respiration, interaction with our dermis, are factors that are going to modify our epigenome and therefore we are going to leave them in our heritage. This by itself, justifies that we should worry much more about the health of our Exposome then we currently are.

Risk factors and their influence are increasingly understood. Examples such as tobacco smoke, inhalation of PM2.5 particles, contact with heavy metals, chlorination products in drinking water, Occupational hazards, etc. What is still unknown is the combined effect of all these factors on the population.

Around three quarters of people die from chronic diseases, mainly CVD and cancer. (2) These diseases result from a combination of genetic (G) and environmental (E -Exposome) factors. Genetic studies, or GWAS (Genetic-Wide Association studies) are those that look for the origin of the disease in the genes. The explanation based on genetics has been amazingly completed with new biochemical techniques, but it has been found that the genetic component represents a very low percentage of the causes of the disease. On the other hand, the EWAS studies (Exposome-wide association studies) or those that try to measure the cause of the disease by environmental factors is still deficient: It is based on questionnaires, geographic information and specific measurements, the type of research that was done a century ago.

Meanwhile, we have no choice but to take precautions and protect ourselves to the greatest extent from the agents proven harmful in the studies. Eating healthy, having non-sedentary habits, and making sure we breathe healthy air are obvious and affordable steps. In cases where the absence of contaminants cannot be guaranteed, the use of purification systems that increase the Fresh Air Factor (Open Air Factor) such as hydroxyl emitters or natural detergent to neutralize them, are advisable.

(1) Wild, C.P., Cancer Epidemiol Biomarkers Prev 14(8), 1847-1850 (2005). Christopher P. Wild, a molecular epidemiologist and director of the International Agency for Research on Cancer in the United States, first defined this concept in 2005.
YE. Rappaport University of California, Berkeley -Research support from NIEHS and the American Chemistry Council