Risks in Perspective:

Quantitative risk characterizations need to be viewed in perspective.

If plaintiff experts use regulatory cancer potencies and other regulatory  characterizations of health risk, then the regulatory overestimation bias needs to be understood and made clear to all concerned.  Regulatory agencies insist on upper-bound characterizations that are biased toward overestimating any real risks.  The regulatory agency's goal is to err on the side of health protection by going to great lengths to avoid underestimation of the magnitude of the risk to the public.  In pursuit of this goal, risk assessments developed under regulatory guidelines result in upper-bound risk characterizations that may greatly overestimate the risks and are not intended to be construed as real risks or accurate estimates of actual risks. 

            The magnitudes of numerical risk characterizations are often confusing and misunderstood.  How big is one-in-a-million or one-in-a-billion?  Simple examples and appropriate analogies can help.

            The risks alleged by plaintiffs' experts do not exist in a vacuum.  There are also background levels of those same risks as well as risks from naturally occurring carcinogens and human activities.