Select Projects

Toxicology Assessment:  Evaluated the toxicological significance and human health risks of exposure to per- and polyfluoroalkyl substances (PFAS) in drinking water and ambient air.  Reviewed the literature regarding animal toxicology and human health effects, as well as the historical state of knowledge of these topics.

Health Risk Evaluation:  Evaluated the potential for cancer and noncancer health effects from exposures to ethylene oxide in ambient air and assessed available regulatory evaluations of human health risks of ethylene oxide.

Carcinogenicity Assessment:  Evaluated whether the weight of epidemiology, animal toxicity, mechanistic, and pharmacokinetic evidence indicates that toluene diisocyanate is a human carcinogen.  This analysis used Gradient’s hypothesis-based weight-of-evidence approach and was published in a peer-reviewed journal.

Review of Toxicogenomics:  Critically reviewed global gene expression profiling data for a population exposed to benzene and determined whether the expression profile could be used as a biomarker of benzene toxicity in a broader population, particularly without proof of benzene exposure from a specific source.

Risk Evaluation:  Evaluated the potential lung cancer risk from exposure to asbestos during vehicle brake repair and considered the association between cigarette smoking and lung cancer in comparison to that expected from asbestos exposure.

Weight-of-Evidence Analysis:  Used Gradient’s hypothesis-based weight-of-evidence approach to assess whether the epidemiology, toxicology, and mechanistic evidence supports chlorpyrifos being a neurobehavioral toxicant in humans at relatively low exposure levels.  This work was published in a peer-reviewed journal.

Regulatory Comment:  Provided written and oral comments on several occasions to US EPA on clinical and epidemiology studies and their bearing on US EPA’s National Ambient Air Quality Standards (NAAQS) for ozone.