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. Liakoni E, Nardone N, St Helen G, Dempsey DA, Tyndale RF, Benowitz NL. Effects of Nicotine Metabolic Rate on Cigarette Reinforcement. 2019. PMID: 31725872

  2. Jacob P, St Helen G, Yu L, Nardone N, Havel C, Cheung P, Benowitz NL. Biomarkers of Exposure for Dual Use of Electronic Cigarettes and Combustible Cigarettes: Nicotelline, NNAL, and Total Nicotine Equivalents. 2019. PMID: 31833541

  3. Benowitz NL, Helen GS, Nardone N, Cox LS, Jacob P. Urine Metabolites for Estimating Daily Intake of Nicotine from Cigarette Smoking. 2019. PMID: 30852610

  4. St Helen G, Nardone N, Addo N, Dempsey D, Havel C, Jacob P, Benowitz N. Differences in nicotine intake and effects from electronic and combustible cigarettes among dual users. 2019. PMID: 31691397

  5. Benowitz N, Nardone N, St Helen G, Addo N, Jacob P, Liakoni E, Jain S, Hooshfar S, Lynch K. Quantitative biochemical screening for marijuana use and concordance with tobacco use in urban adolescents. 2019. PMID: 31600618

  6. Liakoni E, St Helen G, Dempsey DA, Jacob P, Tyndale RF, Benowitz NL. Relationship between skin melanin index and nicotine pharmacokinetics in African American smokers. 2019. PMID: 31521954

  7. St Helen G, Benowitz NL, Ko J, Jacob P, Gregorich SE, Pérez-Stable EJ, Murphy SE, Hecht SS, Hatsukami DK, Donny EC. Differences in exposure to toxic and/or carcinogenic volatile organic compounds between Black and White cigarette smokers. 2019. PMID: 31406274

  8. Nardone N, Helen GS, Addo N, Meighan S, Benowitz NL. JUUL electronic cigarettes: Nicotine exposure and the user experience. 2019. PMID: 31408770

  9. Stroud L, Werner E, Matteson K, Carey M, Helen GS, Eissenberg T, Scott-Sheldon LAJ. Waterpipe (hookah) tobacco use in pregnancy: use, preferences and perceptions of flavours. Volume 29 of Issue Suppl 2. 2019. PMID: 31320397

  10. St Helen G, Benowitz NL, Ahluwalia JS, Tyndale RF, Addo N, Gregorich SE, Pérez-Stable EJ, Cox LS. Black Light Smokers: How Nicotine Intake and Carcinogen Exposure Differ Across Various Biobehavioral Factors. 2019. PMID: 31084916

  11. Liakoni E, Edwards KC, St Helen G, Nardone N, Dempsey DA, Tyndale RF, Benowitz NL. Effects of Nicotine Metabolic Rate on Withdrawal Symptoms and Response to Cigarette Smoking After Abstinence. 2018. PMID: 30242831

  12. Elias J, Dutra LM, St Helen G, Ling PM. Revolution or redux? Assessing IQOS through a precursor product. 2018. PMID: 30305324

  13. St Helen G, Jacob Iii P, Nardone N, Benowitz NL. IQOS: examination of Philip Morris International's claim of reduced exposure. 2018. PMID: 30158205

  14. St Helen G, Eaton DL. Public Health Consequences of e-Cigarette Use. Volume 178 of Issue 7. 2018. PMID: 29801158

  15. St Helen G, Shahid M, Chu S, Benowitz NL. Impact of e-liquid flavors on e-cigarette vaping behavior. 2018. PMID: 29879680

  16. Velicer C, St Helen G, Glantz SA. Tobacco papers and tobacco industry ties in regulatory toxicology and pharmacology. Volume 39 of Issue 1. 2017. PMID: 29116189

  17. Havel CM, Benowitz NL, Jacob P, St Helen G. An Electronic Cigarette Vaping Machine for the Characterization of Aerosol Delivery and Composition. 2017. PMID: 27281605

  18. Benowitz NL, Jain S, Dempsey DA, Nardone N, Helen GS, Jacob P. Urine Cotinine Screening Detects Nearly Ubiquitous Tobacco Smoke Exposure in Urban Adolescents. 2017. PMID: 28031377

  19. St Helen G, Dempsey DA, Havel CM, Jacob P, Benowitz NL. Impact of e-liquid flavors on nicotine intake and pharmacology of e-cigarettes. 2017. PMID: 28704768

  20. Schick SF, Blount BC, Jacob P, Saliba NA, Bernert JT, El Hellani A, Jatlow P, Pappas RS, Wang L, Foulds J, Ghosh A, Hecht SS, Gomez JC, Martin JR, Mesaros C, Srivastava S, St Helen G, Tarran R, Lorkiewicz PK, Blair IA, Kimmel HL, Doerschuk CM, Benowitz NL, Bhatnagar A. Biomarkers of exposure to new and emerging tobacco delivery products. 2017. PMID: 28522563

  21. St Helen G, Ross KC, Dempsey DA, Havel CM, Jacob P, Benowitz NL. Nicotine Delivery and Vaping Behavior During ad Libitum E-cigarette Access. 2016. PMID: 28393086

  22. St Helen G, Havel C, Dempsey DA, Jacob P, Benowitz NL. Nicotine delivery, retention and pharmacokinetics from various electronic cigarettes. 2015. PMID: 26430813

  23. St Helen G, Aguilar-Villalobos M, Adetona O, Cassidy B, Bayer CW, Hendry R, Hall DB, Naeher LP. Exposure of pregnant women to cookstove-related household air pollution in urban and periurban Trujillo, Peru. Volume 70 of Issue 1. 2015. PMID: 24215174

  24. St Helen G, Jacob P, Peng M, Dempsey DA, Hammond SK, Benowitz NL. Intake of toxic and carcinogenic volatile organic compounds from secondhand smoke in motor vehicles. 2014. PMID: 25398951

  25. St Helen G, Benowitz NL, Dains KM, Havel C, Peng M, Jacob P. Nicotine and carcinogen exposure after water pipe smoking in hookah bars. 2014. PMID: 24836469

  26. Dempsey DA, St Helen G, Jacob P, Tyndale RF, Benowitz NL. Genetic and pharmacokinetic determinants of response to transdermal nicotine in white, black, and Asian nonsmokers. 2013. PMID: 23933970

  27. Jones IA, St Helen G, Meyers MJ, Dempsey DA, Havel C, Jacob P, Northcross A, Hammond SK, Benowitz NL. Biomarkers of secondhand smoke exposure in automobiles. 2013. PMID: 23349229

  28. Benowitz NL, Dempsey D, Tyndale RF, St Helen G, Jacob P. Dose-independent kinetics with low level exposure to nicotine and cotinine. 2013. PMID: 22574797

  29. St Helen G, Dempsey D, Wilson M, Jacob P, Benowitz NL. Racial differences in the relationship between tobacco dependence and nicotine and carcinogen exposure. 2012. PMID: 22971134

  30. St Helen G, Holland NT, Balmes JR, Hall DB, Bernert JT, Vena JE, Wang JS, Naeher LP. Utility of urinary Clara cell protein (CC16) to demonstrate increased lung epithelial permeability in non-smokers exposed to outdoor secondhand smoke. Volume 23 of Issue 2. 2012. PMID: 22805990

  31. St Helen G, Novalen M, Heitjan DF, Dempsey D, Jacob P, Aziziyeh A, Wing VC, George TP, Tyndale RF, Benowitz NL. Reproducibility of the nicotine metabolite ratio in cigarette smokers. 2012. PMID: 22552800

  32. St Helen G, Bernert JT, Hall DB, Sosnoff CS, Xia Y, Balmes JR, Vena JE, Wang JS, Holland NT, Naeher LP. Exposure to secondhand smoke outside of a bar and a restaurant and tobacco exposure biomarkers in nonsmokers. Volume 120 of Issue 7. 2012. PMID: 22484462

  33. St Helen G, Goniewicz ML, Dempsey D, Wilson M, Jacob P, Benowitz NL. Exposure and kinetics of polycyclic aromatic hydrocarbons (PAHs) in cigarette smokers. 2012. PMID: 22428611

  34. St Helen G, Hall DB, Kudon LH, Pearce J, Baptiste S, Ferguson S, Green T, Naeher LP. Particulate matter (PM2.5) and carbon monoxide from secondhand smoke outside bars and restaurants in downtown Athens, Georgia. Volume 74 of Issue 3. 2011. PMID: 22010328

  35. Hall JC, Bernert JT, Hall DB, St Helen G, Kudon LH, Naeher LP. Assessment of exposure to secondhand smoke at outdoor bars and family restaurants in Athens, Georgia, using salivary cotinine. Volume 6 of Issue 11. 2009. PMID: 19757294