[Reference values: from guidance values to the exposome.]

OBJECTIVES: The correspondence between biomarkers and the complex interaction of toxics with the human organism has been fully described years ago by the American National Research Council which developed a precious diagram.

METHODS: This model is still valid in describing the new methodologic agnostic or "omic" approaches to the science of exposure.

RESULTS: Reference values and exposome share indeed the search for internal dose biomarkers; adduttomics may be seen as an evolution of the target dose markers while epigenetics itself is a new way of exploring the world of early effect biomarkers.