Genetics, Epigenetics, and Environmental Interactions

Genetics refers to heritable variability that encodes for our various traits and is hardwired in the DNA of the individual. In contrast, epigenetics refers to non-genetic alterations that can influence expression of traits without actually changing the genetic code. Interpersonal variability in the genetic code, along with epigenetic programing that is set during early embryonic development but remains malleable throughout the life course, is what sets individuals apart from one another by providing diversity in manifested traits, ranging from physical appearance to chemical metabolism and DNA damage repair. This diversity, in conjunction with the various physical, chemical, and biological exposures that are encountered—including those in the occupational setting—combine to modulate cancer risk. Therefore, it is important to comprehend how genetics and epigenetics interact with environmental exposures to understand how occupational factors influence development of malignant disease. This chapter provides an introduction to basic concepts in genetics and epigenetics and how they interact with the environment.