Standard Article

Extra Risk

Environmental Health

  1. R. Webster West

Published Online: 15 JAN 2013

DOI: 10.1002/9780470057339.vae058.pub2

Encyclopedia of Environmetrics

Encyclopedia of Environmetrics

How to Cite

West, R. W. 2013. Extra Risk . Encyclopedia of Environmetrics. 2.

Author Information

  1. Texas A&M University, College Station, TX, USA

Publication History

  1. Published Online: 15 JAN 2013


To properly quantify the toxic effect of a toxin, the background risk of no exposure to the toxin, R (0), must first be specified. The excess risk incurred by exposure to a dose, d, of the toxin is then viewed as the added risk at this dose relative to the rate of nonadverse responses, 1 − R(0), in the unexposed population.