Abstract
This chapter focuses on epigenetics: the study of stable, often heritable changes that influence gene expression but are not mediated by DNA sequence. These changes play crucial roles in chromatin state regulation which influences processes such as gene expression, DNA repair, and recombination. Evidence demonstrates that epigenetic patterns are altered by environmental factors which are associated with disease risk including diet, smoking, alcohol intake, environmental toxicants, and stress. Studiers have linked environmental pollutants with epigenetic variations particularly changes in DNA methylation, histone modifications, and microRNAs. Growing data have linked epigenetic alterations with heavy metal exposure, organic toxicants, and water chlorination by-products. Studies focusing on the effects of air pollution in humans demonstrate an association between exposure to air pollution and DNA methylation. Several classes of pesticides can modify epigenetic marks, including endocrine disruptors, persistent organic pollutants, arsenic, several herbicides, and insecticides. This chapter explores epigenetics.