Millions of Americans use e-cigarettes. Despite their popularity, little is known about their health effects. Some suggest that e-cigarettes likely confer lower risk compared to combustible tobacco cigarettes, because they do not expose users to toxicants produced through combustion. Proponents of e-cigarette use also tout the potential benefits of e-cigarettes as devices that could help combustible tobacco cigarette smokers to quit and thereby reduce tobacco-related health risks. Others are concerned about the exposure to potentially toxic substances contained in e-cigarette emissions, especially in individuals who have never used tobacco products such as youth and young adults. Given their relatively recent introduction, there has been little time for a scientific body of evidence to develop on the health effects of e-cigarettes.

Public Health Consequences of E-Cigarettes reviews and critically assesses the state of the emerging evidence about e-cigarettes and health. This report makes recommendations for the improvement of this research and highlights gaps that are a priority for future research.

Contents

• The National Academies of SCIENCES • ENGINEERING • MEDICINE
• COMMITTEE ON THE REVIEW OF THE HEALTH EFFECTS OF ELECTRONIC NICOTINE DELIVERY SYSTEMS
• Reviewers
• Preface
• Summary
  • CONSTITUENTS
  • HUMAN HEALTH EFFECTS
  • INITIATION AND CESSATION
  • HARM REDUCTION
  • MODELING
  • RESEARCH RECOMMENDATIONS
  • FINAL OBSERVATIONS
• Summary Annex: Report Conclusions by Level of Evidence
  • CONCLUSIVE EVIDENCE
  • SUBSTANTIAL EVIDENCE
  • MODERATE EVIDENCE
  • LIMITED EVIDENCE
  • INSUFFICIENT EVIDENCE
  • NO AVAILABLE EVIDENCE
• 1. Introduction
  • STATEMENT OF TASK
  • A NOTE ON TERMINOLOGY: WHAT ARE E-CIGARETTES?
  • THE RAPID RISE OF E-CIGARETTE USE IN THE UNITED STATES
  • POTENTIAL PUBLIC HEALTH RISKS AND BENEFITS OF E-CIGARETTES
  • REGULATORY BACKGROUND
  • OUTLINE OF THE REPORT
  • REFERENCES
• 2. Committee Approach
  • LITERATURE SEARCH
  • LITERATURE REVIEW AND QUALITY ASSESSMENT
  • APPROACH TO ASSESSING CAUSALITY
  • CONCLUSIONS
  • REFERENCES
• I. Section I: E-Cigarette Devices, Constituents, and Exposures
  • 3. E-Cigarette Devices, Uses, and Exposures
    • CHARACTERISTICS OF E-CIGARETTE DEVICES
    • E-CIGARETTE USE
    • EXPOSURE TO AEROSOLS AND PARTICULATES
    • SECONDHAND EXPOSURE TO E-CIGARETTE AEROSOL
    • REFERENCES
  • 4. Nicotine
    • CONCENTRATION OF NICOTINE IN COMMERCIAL E-CIGARETTES
    • NICOTINE CONCENTRATION IN E-CIGARETTE EMISSIONS
    • pH OF E-LIQUIDS
    • NICOTINE SALTS
    • TOXICOLOGY AND MODES OF ACTION
    • EXPOSURE TO NICOTINE AND NICOTINE DERIVATIVES FROM E-CIGARETTES
    • RELATIONSHIP BETWEEN E-CIGARETTE TOPOGRAPHY AND NICOTINE EXPOSURE
    • SYNTHESIS
    • REFERENCES
  • 5. Toxicology of E-Cigarette Constituents
    • HUMECTANTS (DELIVERY SOLVENTS)
    • FLAVORINGS
    • CARBONYL COMPOUNDS
    • MINOR TOBACCO ALKALOIDS
    • TOBACCO-SPECIFIC NITROSAMINES
    • FREE RADICALS AND REACTIVE OXYGEN SPECIES
    • OTHER TOXICANTS
    • SYNTHESIS
    • METALS
    • REFERENCES
  • 6. Research Needs: E-Cigarette Devices, Constituents, and Exposures
    • ADDRESSING GAPS IN SUBSTANTIVE KNOWLEDGE
    • IMPROVING RESEARCH METHODS AND QUALITY
    • REFERENCE
• II. Section II: Effects of E-Cigarettes on Health
  • 7. Modes of Action
    • ENDOTHELIAL CELL DYSFUNCTION
    • OXIDATIVE STRESS
    • CONCLUSIONS
    • REFERENCES
  • 8. Dependence and Abuse Liability
    • CHARACTERIZATION OF DISEASE ENDPOINTS AND INTERMEDIATE OUTCOMES
    • OPTIMAL STUDY DESIGN
    • QUESTIONS ADDRESSED BY THE LITERATURE
    • EPIDEMIOLOGY
    • HUMAN LABORATORY STUDIES
    • CONCLUSIONS
    • REFERENCES
  • 9. Cardiovascular Disease
    • CHARACTERIZATION OF DISEASE ENDPOINTS AND INTERMEDIATE OUTCOMES
    • EVIDENCE FROM HUMAN STUDIES OF CARDIOVASCULAR EFFECTS
    • CONCLUSIONS
    • REFERENCES
  • 10. Cancers
    • CHARACTERIZATION OF DISEASE ENDPOINTS AND INTERMEDIATE OUTCOMES
    • OPTIMAL STUDY DESIGN
    • EPIDEMIOLOGY
    • CASE REPORTS AND OTHER CLINICAL STUDIES
    • IN VIVO ANIMAL STUDIES
    • STUDIES OF EFFECTS OF MAJOR COMPONENTS OF E-CIGARETTES ON CANCER OUTCOMES
    • VULNERABLE/SUSCEPTIBLE POPULATIONS
    • SYNTHESIS
    • REFERENCES
  • 11. Respiratory Diseases
    • CHARACTERIZATION OF DISEASE ENDPOINTS AND INTERMEDIATE OUTCOMES
    • OPTIMAL STUDY DESIGN
    • QUESTIONS ADDRESSED BY THE LITERATURE
    • CLINICAL AND EPIDEMIOLOGICAL STUDIES IN HUMANS
    • IN VIVO ANIMAL STUDIES AND IN VITRO MECHANISTIC STUDIES
    • SYNTHESIS AND CONCLUSIONS
    • VULNERABLE/SUSCEPTIBLE POPULATIONS
    • REFERENCES
  • 12. Oral Diseases
    • CHARACTERIZATION OF DISEASE ENDPOINTS AND INTERMEDIATE OUTCOMES
    • OPTIMAL STUDY DESIGN
    • QUESTIONS ADDRESSED BY THE LITERATURE
    • STUDIES IN HUMANS (CLINICAL AND EPIDEMIOLOGICAL)
    • IN VITRO STUDIES
    • SYNTHESIS
    • REFERENCES
  • 13. Developmental and Reproductive Effects
    • CHARACTERIZATION OF DISEASE ENDPOINTS AND INTERMEDIATE OUTCOMES
    • OPTIMAL STUDY DESIGN
    • QUESTIONS ADDRESSED BY THE LITERATURE
    • EPIDEMIOLOGY
    • CASE REPORTS AND OTHER CLINICAL STUDIES
    • IN VIVO ANIMAL AND IN VITRO/MECHANISTIC STUDIES
    • STUDIES ON COMBUSTIBLE TOBACCO AND NICOTINE
    • SYNTHESIS
    • REFERENCES
  • 14. Injuries and Poisonings
    • BURNS AND EXPLOSIONS
    • INTENTIONAL AND UNINTENTIONAL EXPOSURE TO E-LIQUID
    • REFERENCES
  • 15. Research Needs: Effects of E-Cigarettes on Health
    • ADDRESSING GAPS IN SUBSTANTIVE KNOWLEDGE
    • IMPROVING RESEARCH METHODS AND QUALITY
    • REFERENCE
• III. Section III: Public Health Implications of E-Cigarettes
  • 16. Combustible Tobacco Cigarette Smoking Among Youth and Young Adults
    • CONCEPTUAL FRAMEWORK: PATTERNS OF USE AMONG YOUTH AND YOUNG ADULTS
    • EVIDENCE REVIEW: LEVELS OF EVIDENCE AVAILABLE
    • EVIDENCE REVIEW: METHODS
    • EVIDENCE REVIEW: RESULTS
    • SYNTHESIS
    • REFERENCES
  • 17. Smoking Cessation Among Adults
    • CONCEPTUAL FRAMEWORK: PATTERNS OF E-CIGARETTE USE AMONG ESTABLISHED SMOKERS
    • EVIDENCE REVIEW: LEVELS OF EVIDENCE AVAILABLE
    • EVIDENCE REVIEW: METHODS
    • EVIDENCE REVIEW: RESULTS
    • SYNTHESIS
    • CONCLUSIONS
    • REFERENCES
  • 18. Harm Reduction
    • EVIDENCE REVIEW: LEVELS OF EVIDENCE AVAILABLE
    • EVIDENCE REVIEW: METHODS
    • EVIDENCE REVIEW: RESULTS
    • REFERENCES
  • 19. Modeling of E-Cigarette Use
    • MODEL
    • MODELING ASSUMPTIONS
    • SIMULATION SCENARIOS
    • RESULTS
    • SUMMARY
    • REFERENCES
  • 20. Research Needs: Public Health Implications of E-Cigarettes
    • ADDRESSING GAPS IN SUBSTANTIVE KNOWLEDGE
    • IMPROVING RESEARCH METHODS AND QUALITY
    • REFERENCE
  • 21. Concluding Observations
    • REFERENCES
• APPENDIXES
  • A. Questions from the Center for Tobacco Products of the Food and Drug Administration Submitted for the Committee's Consideration
  • B. Search Strategy and Quality Assessment
  • C. Glossary of Terms Related to E-Cigarettes
  • D. Cytotoxicity Tables
  • E. Public Meeting Agenda
  • F. Committee Biosketches

Suggested citation:

National Academies of Sciences, Engineering, and Medicine. 2018. Public health consequences of e-cigarettes. Washington, DC: The National Academies Press. doi: https://doi.org/10.17226/24952.