Gradient Senior Scientists
Leslie A. Beyer, M.S., DABT
Ms. Beyer is a senior project manager and toxicologist with over 20 years of experience. Her areas of expertise include environmental health, occupational health and safety, litigation support, project management, and risk assessment. Her projects have covered a variety of topics, including substantiation of structure-function claims for dietary supplements; historical toxicology of vinyl chloride, benzene, and lead; and review and interpretation of toxicological and epidemiological literature and data. She evaluates the significance of occupational and residential exposures, conducts health risk assessments for cancer and non-cancer endpoints, and assesses health effects from exposure to environmental chemicals. Ms. Beyer conducts in-depth technical analyses on a range of projects involving product liability and chemical exposures (e.g., MTBE, dioxin, perchloroethylene, ozone, chromium).
Analysis of MTBE Carcinogenicity: Conducted an in-depth analysis of available literature to evaluate the reliability of the findings for individual tumor types in rodents exposed to MTBE (e.g., Leydig cell tumors, leukemia/lymphoma, kidney tumors, and liver tumors), and assessed their relevance to humans. Conducted a prevalence analysis and determined that Leydig cell tumors in rats was not statistically significantly increased when age was taken into account.
Analysis of US EPA Proposed Ozone NAAQS: In 2007, US EPA proposed to reduce the NAAQS standard for ozone from 0.08 ppm ozone to a concentration within the range of 0.070 to 0.075 ppm, based on recent findings in human health studies. Gradient analyzed US EPA's use of studies to support its proposed standard, and assessed the strength of a causal relationship for a number of endpoints. The analysis was used as part of regulatory comments submitted to US EPA by a trade association.
Dioxin Health Impacts Near a Pigment Manufacturing Facility: Examined whether a manufacturing facility was responsible for health problems of residential neighbors. Compared dioxin congener pattern data from plaintiffs’ blood serum to soils, house dust, sediments, shellfish, food, and other background sources. Also compared diseases with epidemiological and toxicological literature on dioxins (and some metals) and critiqued plaintiffs’ experts reports and unorthodox approaches to exposure and risk assessment.
Structure-Function Claim Evaluation for Dietary Supplements: Conducted comprehensive literature searches, purchased the most relevant literature, reviewed the literature, and summarized each article/document in a tabular format, providing detailed information on the methods, findings, conclusions, strengths, and weaknesses. Compared this documentation to products’ structure-function claims to assess degree of support provided.
Goodman, JE; Gaylor, D; Beyer, LA; Rhomberg, LR; Beck, BD. 2008. "Effects of MTBE on the reported incidence of Leydig cell tumors in SpragueDawley rats: Range of possible Poly-3 results." Regul. Toxicol. Pharmacol. 50: 273-284.