January 20th is Weedless Wednesday, a focal point for National Non-Smoking Week. In this story, we report further on the emergence of e-cigarettes, which are beginning to eclipse tobacco cigarettes in use among young people.
Tracking a moving target -- that’s the challenge for researchers who are trying to get a handle on the long-term health effects of e-cigarettes, and their potential as a cessation aid for smokers of tobacco cigarettes.
As e-cigarette usage (or vaping) has begun to eclipse that of tobacco among young people, “the product is changing constantly – an e-cigarette in Toronto may be very different from an e-cigarette in Sudbury or New York City,” Dr. Robert Schwartz, CAMH Senior Scientist in Social and Epidemiological Research, told an international research panel in Toronto.
“We are seeing a range of devices, mechanisms and contents,” says Dr. Schwartz, who heads up the Ontario Tobacco Research Unit (OTRU). “For example, some e-cigarettes may deliver as much nicotine in 10 puffs as a tobacco cigarette, and we know that nicotine can affect brain development. Other e-cigarettes may contain little or no nicotine.”
The huge variation in product, wide availability of e-cigarettes, and lack of regulation in many areas, has made it a difficult but important area to study, he said.
This month, Dr. Schwartz hosted an international expert panel at the University of Toronto’s Dalla Lana School of Public Health. The panel is part of a comprehensive Research on E-cigarettes (RECIG) project funded by the Ontario Ministry of Health and Long-Term Care, Health System Research Fund.
In an overview presentation, Dr. Schwartz and his CAMH colleague, Clinician-Scientist Dr. Laurie Zawertailo, noted some “take home messages” for the public and policymakers based on findings to date:
There is sufficient evidence on health effects to suggest that anybody who is not a current smoker of tobacco cigarettes should not vape e-cigarettes
Compounds including carbonyls, TSNAs (tobacco-specific nitrosamines, which are carcinogenic) and impurities are frequently detected in e-liquids; low levels of carbonyls, VOCs (volatile organic compounds), TSNAs, metals, impurities and particulate matter have been detected in e-cigarette vapour; studies suggest e-cigarette vapour may have some cytotoxic (cell-killing) effects.
Nicotine and other compounds are released into the environment and may result in passive exposure from e-cigarette use.
E-cigarettes generally contain low levels of toxicants compared to tobacco cigarettes
E-cigarette rates among young people are a concern as they have begun to eclipse rates for tobacco use among young people. In the latest CAMH survey (2015 Ontario Student Drug Use and Health Survey -- OSDUHS), about 12 per cent of students in Grades 7-12 reported using e-cigarettes (more than just a few puffs) compared to about nine per cent for tobacco.
For youth, nicotine can affect brain development.
Second-hand smoke from e-cigarettes is lower than for tobacco, but it may result in low-level exposure to nicotine, organic compounds, metals and particulate matter.
Potential for addiction
Most people who have tried e-cigarettes do not continue to use them.
Effectiveness of e-cigarettes as a cessation aid
Some tobacco smokers who use certain kinds of e-cigarettes in certain ways may quit tobacco smoking
E-cigarettes may present another option for tobacco cessation, but results on relative effectiveness are just starting to emerge.
Most smokers who tried quitting with e-cigarettes vaped only a few times, and did not quit smoking tobacco.
Some key points from other presenters on the international panel:
Dr. Thomas Eissenberg, Virginia Commonwealth University: Regular e-cigarette users typically take puffs about twice as long in duration as novice e-cigarette smokers. Nicotine in e-cigarette delivery can exceed that inhaled from a tobacco cigarette.
Dr. Alan Shihadeh, American University of Beirut: Puff duration, not velocity, increases the nicotine yield of e-cigarettes. E-cigarette regular users tend to take longer, slower puffs, to maximize nicotine delivery.
Dr. Mirjana Djordjevic, National Cancer Institute (U.S.): More than 70 studies are underway through TCORS (Tobacco Centers of Regulatory Science) on e-cigarette issues, including use among college students. E-cigarette use and effects are being assessed in a longitudinal study of 32,000 adults.
Dr. Maciej Goniewicz, Roswell Park Cancer Institute (U.S.): E-cigarette toxicants tend to be lower across the board compared to tobacco toxicants, while nicotine exposure tends to be unchanged.
Professor Linda Bauld, Cancer Research UK: Use of e-cigarettes for tobacco cessation is increasing in the UK. Tobacco smokers who have tried other methods to quit should not be discouraged from trying e-cigarettes to quit tobacco.
The Ontario RECIG research project encompasses a longitudinal study of adult smokers, in-depth interviews with youth and young adults, social media analysis, a clinical trial looking at cessation effectiveness, and a biomarker study of e-cigarette contents. In addition, the study analyzes existing surveys and synthesizes international knowledge. Launched in 2014, the study will conclude later this year. Learn more about RECIG on the OTRU web site.