Aging of an organism appears to be a precursor for most, if not all disease outcomes. However, some diseases associated with aging are due to genetic mutations, while others occur even without altering the genetic sequence, through a phenomenon known as epigenetics. DNA methylation and histone modifications are classic examples of epigenetic modifications. These modifications appear to be in a constant flux and, therefore, can be altered by exposure to environmental insults over the life time of the organism. This chapter focuses on how environmental conditions such as heat stress, exposure to metals, and nurturing can affect the dynamic epigenetic modifications in aging. In addition, how these modifications can either directly or indirectly result in age-associated pathologies are also addressed.