The exposome is generally understood as a measure of all the exposures, environmental or lifestyle, an individual experiences over lifetime. It was first mentioned in a 2005 paper by Christopher P Wild (10.1158/1055-9965.EPI-05-0456) who stated, " Unlike the genome, the exposome is a highly variable and dynamic entity that evolves throughout the lifetime of the individual." Major exposomics research initiatives include Emory University's HERCULES Exposome Research Center, and the European Union's Human Early-Life Exposome (HELIX) and Health and Environment-wide Associations based on Large population Surveys (HEALS) projects.
To learn more, and for links to additional resources, see:
Environmental health and toxicology - produced and maintained by Specialized information Services, National Library of Medicine
Exposome and exposomics - produced and maintained by the National Institute for Occuopational Safety and Health, Centers for Disease Control
Exposome, an Overview (Science Direct)