Gradient

Principals

Lorenz R. Rhomberg, Ph.D., ATS
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Education

Ph.D., Population Biology, State University of New York at Stony Brook

B.Sc. (Honours, Biology), Queen's University, Ontario

Fellow, Academy of Toxicological Sciences

Expertise

  • Weighing Toxicologic Evidence
  • Quantitative Risk Methods
  • Pharmacokinetic Modeling
  • Chlorinated Solvents
  • Risk Policy & Methodology
  • Cumulative Risk

Lorenz R. Rhomberg, Ph.D., ATS

Principal

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Dr. Rhomberg is an expert in quantitative risk assessment, including dose-response analysis, pharmacokinetic modeling, and probabilistic methods, with special experience in chlorinated solvents and endocrine-active agents. He is the author of books and of more than 50 articles on these topics.  His practice includes work in support of environmental litigation as well as work relating to a variety of regulatory programs including CERCLA, FIFRA, TSCA, and REACH, among others.  Before joining Gradient, Dr. Rhomberg was on the faculty of the Harvard School of Public Health and was employed by US EPA. Dr. Rhomberg is active in professional groups and environmental policy development, focusing on current issues in the interpretation of toxicological data in human health risk assessment through service on panels sponsored by government, industry, and such organizations as the National Academy of Sciences and the International Life Sciences Institute. Dr. Rhomberg was recognized as the Outstanding Practitioner of the Year by the Society for Risk Analysis in 2009.

Education

Ph.D., Population Biology, State University of New York at Stony Brook

B.Sc. (Honours, Biology), Queen's University, Ontario

Fellow, Academy of Toxicological Sciences

Expertise

  • Weighing Toxicologic Evidence
  • Quantitative Risk Methods
  • Pharmacokinetic Modeling
  • Chlorinated Solvents
  • Risk Policy & Methodology
  • Cumulative Risk

Services

Representative Projects

Skin Cancer Risk from Coal Tar Shampoo: Served as a testifying expert for a state government on the analysis of an animal bioassay on skin cancer risk from dermally applied coal tar, which included extrapolation to potential human risks from use of coal tar shampoo.

Potential Human Health Effects of Trichloroethylene: Performed expert evaluation of toxicologic and epidemiologic studies and critique of opposing expert reports in a matter under litigation.

Public Communication and Mediation on Dioxin Sampling: For the US Army, provided expertise to state regulators and a citizens board on the utility and pitfalls of environmental sampling for dioxin contamination near an Army laboratory facility.

"State-of-the-Science" Publication on Trichloroethylene Dose-Response Analysis: Commissioned by US EPA to analyze alternative bases for human carcinogenic potency using pharmacokinetic model results and data from rodent carcinogenicity bioassays.

Chlorinated Solvent Toxicology and Risk from Air Infiltration: Served as an expert defendants' witness regarding toxicologic knowledge of several solvents and potential for health risk to nearby residents based on exposure via infiltration into indoor air from a groundwater plume, in view of plume modeling, indoor air measurements, other plumes from other PRPs, and household chemical use.

Critical Review of US EPA Guidance: Provided critique and public comments on US EPA's proposed supplemental guidelines for assessing cancer risks to children, on behalf of a trade association.

Comprehensive Review of Bisphenol A Toxicity for REACH: Extensively reviewed all relevant scientific studies, summarized in vitro as well as nonoral and oral in vivo studies, and prepared "robust summaries" of those studies conducted under OECD/GLP guidelines, and "short summaries" of overall conclusions of review articles.  The information was compiled in IUCLID 5 for submission to the European Chemicals Agency.

Selected Publications

Rhomberg, LR; Lewandowski, TA.  2006. "Methods for identifying a default cross-species scaling factor." Hum. Ecol. Risk Assess. 12 : 1094-1127.

Lewandowski, TA; Rhomberg, LR.  2005. "A proposed methodology for selecting a trichloroethylene inhalation unit risk value for use in risk assessment." Regul. Toxicol. Pharmacol. 41 : 39-54.

Rhomberg, LR.  2004. "Separating pharmacokinetic and pharmacodynamic components in empirical adjustment factor distributions." Hum. Ecol. Risk Assess. 10 : 79-90.

Evans, JS; Rhomberg, LR; Williams, PL; Wilson, AM; Baird, SJS.  2001. "Reproductive and developmental risks from ethylene oxide: A probabilistic characterization of possible regulatory thresholds." Risk Anal. 21 : 697-717.