Toxicoepigenetics and Environmental Health: Challenges and Opportunities

Abstract

The rapidly growing field of toxicoepigenetics seeks to understand how toxicant exposures interact with the epigenome to influence disease risk. Toxicoepigenetics is a promising field of environmental health research, as integrating epigenetics into the field of toxicology will enable a more thorough evaluation of toxicant-induced disease mechanisms as well as the elucidation of the role of the epigenome as a biomarker of exposure and disease and possible mediator of exposure effects. Likewise, toxicoepigenetics will enhance our knowledge of how environmental exposures, lifestyle factors, and diet interact to influence health. Ultimately, an understanding of how the environment impacts the epigenome to cause disease may inform risk assessment, permit noninvasive biomonitoring, and provide potential opportunities for therapeutic intervention. However, the translation of research from this exciting field into benefits for human and animal health presents several challenges and opportunities. Here, we describe four significant areas in which we see opportunity to transform the field and improve human health by reducing the disease burden caused by environmental exposures. These include (1) research into the mechanistic role for epigenetic change in environment-induced disease, (2) understanding key factors influencing vulnerability to the adverse effects of environmental exposures, (3) identifying appropriate biomarkers of environmental exposures and their associated diseases, and (4) determining whether the adverse effects of environment on the epigenome and human health are reversible through pharmacologic, dietary, or behavioral interventions. We then highlight several initiatives currently underway to address these challenges.

Figure 1.

Schematic illustrating the interplay between the environment, the epigenome, and human health. Numerous environmental toxicants play a role in the etiology of human diseases. A few examples of toxicants linked to disease include perfluoroalkyl substances (PFAS), which are ubiquitous in the environment and bioaccumulate in the human body, tobacco products, and the heavy metal lead. Epigenetic changes may be biomarkers of exposure and/or disease, mechanistic mediators of environment-induced disease, or both. Factors such as sex, age, and allostatic load alter susceptibility to environment-induced disease, but the role of the epigenome in these interactions is currently unclear.