Gideon St Helen, PhD

Assistant Professor

Gideon St.Helen, PhD, is an environmental toxicologist with postdoctoral training in clinical pharmacology. His research interests involve three major themes: (1) understanding the safety and risk of novel tobacco products, such as electronic cigarettes, particularly on the cardiovascular system to inform regulatory policies; (2) examination of the pharmacology and safety of cannabis products, and the interplay/interaction between cannabis and tobacco; and (3) examination of biological and behavioral factors that underlie smoking-related health disparities among American smokers.

Dr. St.Helen received his PhD in toxicology from the University of Georgia followed by postdoctoral training in the Benowitz lab. He joined the UCSF faculty in 2015.
PhD, Environmental Toxicology, 2011 - College of Public Health, University of Georgia
BS, Biology, 2006 - , Livingstone College
  1. Effects of Nicotine Metabolic Rate on Cigarette Reinforcement.
  2. Biomarkers of Exposure for Dual Use of Electronic Cigarettes and Combustible Cigarettes: Nicotelline, NNAL, and Total Nicotine Equivalents.
  3. Twenty-four Hour Subjective and Pharmacological Effects of Ad Libitum Electronic and Combustible Cigarette Use among Dual Users.
  4. Urine Metabolites for Estimating Daily Intake of Nicotine from Cigarette Smoking.
  5. Differences in nicotine intake and effects from electronic and combustible cigarettes among dual users.
  6. Comparison of systemic exposure to toxic and/or carcinogenic volatile organic compounds (VOCs) during vaping, smoking, and abstention.
  7. Quantitative biochemical screening for marijuana use and concordance with tobacco use in urban adolescents.
  8. Relationship between skin melanin index and nicotine pharmacokinetics in African American smokers.
  9. Differences in exposure to toxic and/or carcinogenic volatile organic compounds between Black and White cigarette smokers.
  10. JUUL electronic cigarettes: Nicotine exposure and the user experience.
  11. Waterpipe (hookah) tobacco use in pregnancy: use, preferences and perceptions of flavours.
  12. Black Light Smokers: How Nicotine Intake and Carcinogen Exposure Differ Across Various Biobehavioral Factors.
  13. Effects of Nicotine Metabolic Rate on Withdrawal Symptoms and Response to Cigarette Smoking After Abstinence.
  14. Revolution or redux? Assessing IQOS through a precursor product.
  15. IQOS: examination of Philip Morris International's claim of reduced exposure.
  16. Public Health Consequences of e-Cigarette Use.
  17. Impact of e-liquid flavors on e-cigarette vaping behavior.
  18. Comparison of Urine 4-(Methylnitrosamino)-1-(3)Pyridyl-1-Butanol and Cotinine for Assessment of Active and Passive Smoke Exposure in Urban Adolescents.
  19. Tobacco papers and tobacco industry ties in regulatory toxicology and pharmacology.
  20. An Electronic Cigarette Vaping Machine for the Characterization of Aerosol Delivery and Composition.
  21. Urine Cotinine Screening Detects Nearly Ubiquitous Tobacco Smoke Exposure in Urban Adolescents.
  22. Impact of e-liquid flavors on nicotine intake and pharmacology of e-cigarettes.
  23. Biomarkers of exposure to new and emerging tobacco delivery products.
  24. Effect of UGT2B10, UGT2B17, FMO3, and OCT2 genetic variation on nicotine and cotinine pharmacokinetics and smoking in African Americans.
  25. Nicotine Delivery and Vaping Behavior During ad Libitum E-cigarette Access.
  26. Disposition kinetics and metabolism of nicotine and cotinine in African American smokers: impact of CYP2A6 genetic variation and enzymatic activity.
  27. The Influence of Puff Characteristics, Nicotine Dependence, and Rate of Nicotine Metabolism on Daily Nicotine Exposure in African American Smokers.
  28. Nicotine delivery, retention and pharmacokinetics from various electronic cigarettes.
  29. Exposure of pregnant women to cookstove-related household air pollution in urban and periurban Trujillo, Peru.
  30. Intake of toxic and carcinogenic volatile organic compounds from secondhand smoke in motor vehicles.
  31. Nicotine and carcinogen exposure after water pipe smoking in hookah bars.
  32. Genetic and pharmacokinetic determinants of response to transdermal nicotine in white, black, and Asian nonsmokers.
  33. Stability of the nicotine metabolite ratio in smokers of progressively reduced nicotine content cigarettes.
  34. Biomarkers of secondhand smoke exposure in automobiles.
  35. Dose-independent kinetics with low level exposure to nicotine and cotinine.
  36. Racial differences in the relationship between tobacco dependence and nicotine and carcinogen exposure.
  37. Utility of urinary Clara cell protein (CC16) to demonstrate increased lung epithelial permeability in non-smokers exposed to outdoor secondhand smoke.
  38. Reproducibility of the nicotine metabolite ratio in cigarette smokers.
  39. Exposure to secondhand smoke outside of a bar and a restaurant and tobacco exposure biomarkers in nonsmokers.
  40. Exposure and kinetics of polycyclic aromatic hydrocarbons (PAHs) in cigarette smokers.
  41. Particulate matter (PM2.5) and carbon monoxide from secondhand smoke outside bars and restaurants in downtown Athens, Georgia.
  42. Assessment of exposure to secondhand smoke at outdoor bars and family restaurants in Athens, Georgia, using salivary cotinine.