Environmental epigenetics: from novelty to scientific discipline.

Epigenetic phenomena have sparked much interest resulting in an exponential increase in scientific investigation in the last two decades. While growing, the field of environmental epigenetics remains small when compared to other areas of epigenetic inquiry such as cancer research. In this paper, our objective is to describe the status of the field of environmental epigenetics and lay out our vision for its future. While environmental epigenetic studies represent fewer than 5% of all epigenetic publications, the National Institute of Environmental Health Sciences ranks second in proportion of dollars spent on epigenetics of all NIH Institutes. Such investment highlights the hypothesis that epigenetic marks are modified by environmental exposures and the hope that interventions targeted at epigenetic mechanisms may ultimately lead to improved health outcomes. The road to achieve this vision will require: (1) attention to tissue specificity; (2) focused interventional studies; (3) collaboration among cohorts; (4) inclusion of environmental exposures in new large-scale epigenomic studies; and (5) understanding of multiple mechanisms beyond DNA methylation and histone modifications. The investment in environmental epigenetic inquiry will lead to great rewards if we can understand the biology of how phenotype results from environmental stimuli and genetic code. Understanding the epigenetic implications of our actions and exposures may benefit generations to come.