Ralph Perona
Risk Assessment Specialist

[.]Professional Biography

Ralph Perona specializes in assessing human health risks associated with exposure to chemical and radiological contamination in environmental media. Ralph began working in environmental health in 1988 performing public outreach and regulatory compliance services for a county health department in New Jersey. After earning his MS in Environmental Health, he assisted a state health department in developing a wellhead protection program before joining an enviromental consulting firm as a toxicologist and risk assessor.

As a human health risk assessor, Ralph provides decision support for evaluating and managing complex environmental problems requiring the integration of numerous disciplines including data analysis, exposure assessment, chemical fate and transport among environmental media, toxicology, and uncertainty analysis. His knowledge of the relationships among the different facets of an environmental investigation allow him to develop practical conceptual site models to assist in problem definition, sampling design, and interpretation of data analysis and risk assessment results. Ralph has provided assistance to clients including the Los Alamos National Laboratory, the New Mexico Environment Department, the Department of Defense, Westinghouse Hanford, and private clients in the U.S. and Canada.

Ralph holds an MS in Environmental Health from the University of Washington (1992) and a BS in Food Science from Cook College, Rutgers University (1985). He is experienced in the use of many types of software for performing risk and dose modeling of chemicals and radionuclides in various environmental media and has developed independent models for benchmarking and interpreting commercially available software.

[.]A Personal Look at the Status of Risk Assessment

Human health risk assessment is somewhat unique among the various disciplines that contribute to a successful evaluation of the impacts of environmental contamination in environmental media. Risk assessment is not a well-defined specialty such as geology, statistics, or engineering. Instead, a good risk assessor must be generalist who can orchestrate and integrate the contributions of many such specialties to develop a useful and defensible evaluation of potential health risks. Also, because the metric of a risk assessment is a detrimental health effect in human beings, risk assessment is properly viewed as residing within the field of public health.

Because risk assessment by necessity integrates so many different disciplines, and by virtue of their own training and that of their colleagues, no two risk assessors approach their task in exactly the same way. A risk assessment becomes a unique blend of quantitative analyses and qualitative arguments based on these calculations. The assessment describes potential health effects that are too slight to measure epidemiologically but are nevertheless frequently judged to warrant remedial action. The technical merit of a risk assessment is generally associated with the strength of the qualitative arguments since these become the bases of recommendations for action.

So, different risk assessors are likely to produce different assessments for the same set of conditions and the merit of these assessments lies in the strength of the arguments. This is approximately equivalent to the situation in a legal trial, except in a trial you have two lawyers advocating for their respective clients. A risk assessor is like a lawyer serving two clients simultaneously; one client is the unwittingly exposed public (remember, risk assessment lies within the field of public health) and the other is whomever has hired the assessor to write an assessment.

Maybe the biggest hurdle to using risk assessment as a tool for environmental decision making is the recognition by regulatory agencies and the general public that an assessment can be written to serve a particular client. The arguments can still be well-crafted and the calculations verifiable, it's the myriad of small and large assumptions that create the boundaries of the assessment that are so easy to manipulate. This has created a frustrating environment for both responsible parties and regulatory agencies. Mistrusting risk assessors, and without the resources to thoroughly disect every assessment, regulatory agencies often require that assessments use exceedingly simplified (ie, conservative) assumptions and models. Inevitably, poor remedial decisions are made and cleanup levels are negotiated in the absence of good information on potential risks.

What can be done? A good start would be if practicing risk assessors and risk managers held a common view of risk assessment as a branch of public health. Professional certification in risk assessment would also be helpful by allowing for the development of recognized professional standards. Risk assessment and risk management must be integrated to produce defensible risk-based decisions, and this cannot happen unless the assessor and the manager view themselves as colleagues rather than adverseries.

Last modified: 20 Mar 2002