Arsenic Risk Assessment: The Importance of Speciation in Different Hydrologic Systems Academic Article uri icon


  • The processes impacting arsenic toxicity are a function of molecular speciation, where risk from chronic exposure to the reduced arsenic species is estimated to be four orders of magnitude higher than many oxidized arsenic species. While the adverse health effects of arsenic are generally well known, the impact of speciation on carcinogenic and noncarcinogenic adverse health effects has rarely, if ever, been considered in traditional chronic arsenic exposure risk assessments. Utilizing standard Environmental Protection Agency protocol, lifetime cancer risk and hazard quotient are calculated for chronic arsenic exposure at the local, regional, and national scale to characterize potential risk as a function of arsenic speciation. Additionally, the antagonistic and synergistic impacts of biogeochemical processes on arsenic bioavailability and bioaccessibility are discussed and show chronic exposure risk is likely to be reduced below some maximum value calculated for reduced arsenic species. 2009 Springer Science+Business Media B.V.

published proceedings


author list (cited authors)

  • Markley, C. T., & Herbert, B. E.

citation count

  • 16

complete list of authors

  • Markley, CT||Herbert, BE

publication date

  • November 2009