E-Cigarette Battery Hazards Minuscule and Overblown

Breathless reports of e-cigarette battery explosions have appeared recently in the Journal of the American Dental Association (here) and Cornea (here).  The latter article, alluding to a “number of media reports,” claimed that “e-cigarettes pose a significant public health risk.”  Clive Bates labeled that claim “inappropriate and alarmist” in his excellent PubMed Commons comment (here).

Bates explained that “Risk is a quantitative concept or it is meaningless… Claims that products or behaviours cause significant public health risks need to be proportionate and reflect both absolute risks (how much harm is caused) and relative risks - i.e. set in appropriate context by reference to risks arising from other common products and activities.”

In other words, the risk of e-cig accidents should be assessed in relation to smoking-related accidents.

According to the Federal Emergency Management Agency (FEMA), “Twenty-five separate incidents of explosion and fire involving an e-cigarette were reported in the United States media between 2009 and August 2014…nine injuries and no deaths.” (here)  The agency concluded: “Fires or explosions caused by e-cigarettes are rare.”

In contrast, the FEMA chart above shows that smoking caused 40,000 residential fires, 1,665 fire deaths and 4,550 fire injuries over roughly the same period (source here).  Clearly, a switch from combustible to electronic cigarettes will substantially decrease fire hazards as it reduces the 400,000+ annual deaths from cancers, cardiovascular and lung diseases.

E-cigarettes have lithium-ion batteries.  Battery explosions and fires, which also occur with cell phones and laptop computers, are rare events that can be prevented with quality control in manufacturing and with responsible use -- charging with manufacturer-recommended power adaptors and handling and storing appropriately, for example. 

In any rational analysis, the real public health hazard is smoking.

CDC Knows that Its Data Puts Smokeless Tobacco Risks Near Zero

Knowing that the Centers for Disease Control (CDC) has the means to calculate deaths due to smokeless tobacco – a statistic that is likely to be near zero – I have encouraged readers to call the agency at 800-232-4636 or email them (here) to demand data and sources on the precise dangers of smokeless tobacco use.

Three of my blog readers requested this information from the CDC and shared the agency’s responses.

Brenden Rudnick made the first request (here) in March, after reading one of my blog entries.  The CDC replied:

“...at this time, we do not provide estimates of deaths attributed to the use smokeless tobacco products…We are not aware of a source of this estimate.”

Another reader, F. Chambers, reported a similar response on April 21 (here):

“We do not estimate deaths resulting from the use of smokeless tobacco products and we are not aware of a source of these estimates.”

On April 22, reader Rob advised that the CDC had a more elaborate excuse:

“there are methodological limitations, including in regard to sample size, which impact our ability to calculate comparable estimates for smokeless tobacco. Chapter 12 of the 2015 Surgeon General’s Report (here) describes the limitations in establishing estimates on the cause of death for products other than cigarettes…the lack of appropriate relative risks related to tobacco products other than cigarettes. Further, dual use of cigarettes and another product may complicate estimates, particularly if dual use extends to persons in age ranges where most smoking-caused deaths occur. Therefore, at this time, we do not have an estimate or a timeframe to provide.”

These excuses are unacceptable.  The CDC has all the data it needs to make informed estimates.  Here is proof: Dr. Michael Fisher, a scientist at Altria, used CDC data to calculate the following tobacco use risks, an analysis he presented at a recent tobacco research meeting (here). 

Adjusted Risks* for Tobacco Users in National Health Interview Surveys
Tobacco Use	All Causes of Death	All Cancers	Heart Diseases
Exclusive Smokeless	1.05 (0.90 – 1.23)	1.05 (0.77 – 1.43)	0.94 (0.70 – 1.28)
Exclusive Smoking	2.17 (2.09 – 2.26)	3.08 (2.84 – 3.33)	1.98 (1.85 – 2.13)
Dual Use	2.34 (1.80 – 3.02)	2.78 (1.89 – 4.10)	1.76 (1.03 – 3.01)
Former Smoking	1.35 (1.30 – 1.40)	1.64 (1.52 – 1.78)	1.21 (1.13 – 1.29)
Former Smoking, Current Smokeless	1.38 (1.14 – 1.67)	1.62 (1.13 – 2.31)	1.62 (1.16 – 2.25)
*Compared with never tobacco use

    

The headline here is that the risks for exclusive ST users are not significantly different from those for never users.  In other words, ST users had ZERO excess risks for all causes of death, all cancers and heart diseases.  The rest of the estimates are significantly elevated.  Note that, by Dr. Fisher’s calculation, the risks for dual users are not very different from those for exclusive smokers.  Also note that the risks for former smokers who use ST are about the same as those who quit altogether; both were lower than smokers.

By continuing to obfuscate about the existence and implications of it smokeless risk data, the CDC is failing in its mission to promote public health. Worse, by supporting the false claim that smoke-free products are just as risky as cigarettes, the agency denies smokers vital and persuasive reasons to quit.

The Robust Public Health Case for Tobacco Harm Reduction

Last year, Margarete Kulik and Stanton Glantz (“KG”) proclaimed in Tobacco Control that there is no public health basis for telling smokers about smokeless tobacco and e-cigarettes as safer cigarette alternatives, because the smoking population in the U.S. was “softening,” i.e., becoming more likely to quit (abstract here).    

KG based their conclusion in part on an analysis of public survey data from the Tobacco Use Supplements of the Current Population Survey.  They had information on the percentage of smokers (prevalence), the percentage of smokers who made a quit attempt in the past 12 months, the proportion of former smokers among ever smokers (also called the quit ratio), and daily cigarette consumption (cigarettes per day, or CPD) for each state and for several survey years from 1992 to 2011. Using linear regression, they found that a 1% decline in smoking prevalence is associated with a 0.6% increase in quit attempts, a 1.1% increase in the quit ratio, and a reduction in consumption of 0.3 cigarettes per day (CPD). 

The KG analysis was seriously flawed, as the authors failed to consider other factors that may significantly affect smoking.  For example, KG should have considered data on the percentage of smokers who faced workplace or home smoking bans – information that was available in the survey datasets.  The effect of state cigarette excise taxes should have been weighed.  Additional factors, such as differences in smoking norms and anti-smoking sentiments in the various states, are commonly analyzed through the use of a standard fixed effects variable.  KG did none of this.

My research group has recreated the KG analysis and taken into account the missing variables.  Our results have now been published in the journal Addiction (here).  We found that “KG’s results are not robust…The inclusion of state fixed effects and state-level policies led to a large drop in the coefficients…and became statistically non-significant…the omitted state-level characteristics are most likely responsible for…KG’s results.”

We also note: “One further point needs to be made.  KG claim that their study bears on the question of whether smoke-free tobacco products have a contribution to make to tobacco control.  They claim that much of the argument for smokeless tobacco and e-cigarettes is dependent on the assumption that the smoking population is hardening.  This is not the case. The argument for these considerably safer products is simply that they may be short-term aids to cessation or permanent substitutes for tobacco cigarettes.  In a population such as that in the US, that argument is relevant as long as there are substantial numbers of smokers who will use them.”

For the 39 million smokers in the U.S., there is no public health basis to withhold either safer cigarette substitutes or the potentially life-saving facts about such products.