Commentary: Role of Hormesis in Ecological Risk Assessment

Mohamed T. Elnabarawy, M.S.

Senior Environmental Specialist

3M Company

Environmental Technology and Services

St. Paul, MN 55133-3331

Tel: 651-778-5151

Fax: 651-778-7203

Email: mtelnabarawy@mmm.com

The Implications of Hormesis to Ecotoxicology and Ecological Risk Assessment offers welcome and much needed thoughts on redirecting and advancing the ecotoxicology sciences. The current ecotoxicity testing paradigm is rigid and much in need for alignment with risk assessment data needs. Hormesis is more than just an interesting phenom - its implications are potentially profound. But can it compete for precious research dollars ? The author articulates possible complementary paradigm shifts, but offers no compelling argument for research needs - emphasis on needs.

A greater variability would be expected for individual response to low-dose exposure. How do we translate individual response to community response in ecological risk assessments ? How will this affect the risk assessment of background levels ? Thoughts are needed on how to handle low-dose exposure toxicity of mixtures. How do we assess low-dose environmental exposure (air, water/sediment, or soil) versus dietary exposure ?

I agree, hormesis could play a legitimate and useful role in ecotoxicology and ecological risk assessment. It seems we need to offer the research community some guidance on how to extrapolate low-dose toxicity endpoints. As for the regulators and the regulated community, we can show the role of hormesis in regulatory model development, and how it will affect criteria and standards development. Above all, can we convince the public that hormetic effects are primarily stimulatory effects? There are a number of low-dose negative effects that concern the public. Societal expectations will dictate that we evaluate and understand harmful as well as beneficial outcomes.