Wednesday, October 31, 2012

E-Cigarettes Prove Effective for Smoking Cessation

The scientific foundation for tobacco harm reduction is well established.  My comprehensive reviews of the evidence in 2006 (here) and 2011 (here) were based on 279 articles published primarily in medical and scientific journals.  Dozens more articles were published in the past year.

Tobacco prohibitionists remain blind to this evidence. 

On September 11, the Oklahoma House of Representatives’ Public Health Committee convened a hearing on tobacco harm reduction.  Daniel McGoldrick, Vice President for Research at the Campaign for Tobacco-Free Kids, told legislators that “Tobacco harm reduction is a complicated and risky strategy that currently lacks an evidence base…” 

A particularly vulnerable target of anti-tobacco forces is the e-cigarette, which has been on the market for less than a decade. Even in that short time-frame, scientific studies have emerged to put the lie to “no evidence” charges.  For example, a clinical trial conducted at Italy’s University of Catania and the UK’s University of Southampton (available here) concluded that “…the e-cigarette can help smokers to remain abstinent or reduce their cigarette consumption.  By replacing tobacco cigarettes, the e-cigarette can only save lives.”

Lead author Riccardo Polosa and colleagues enrolled 40 healthy adult smokers who were not interested in quitting into a prospective trial where they were invited to use e-cigarettes with 7.4 mg cartridges at no cost over 24 weeks.  The authors note that “…no emphasis on encouragement, motivation and reward for the smoking cessation effort were provided…”  Twenty-seven participants completed all study visits.

One-third (n=13) of the participants reported a sustained 50% reduction in the number of cigarettes smoked, from 25 per day at enrollment to six per day at completion.  Further, nine participants had completely quit smoking, with six still using e-cigarettes at the end of the study. 

These reports were confirmed by testing carbon monoxide levels in exhaled air.  High levels were measured in all smokers before the study; levels at study’s end confirmed little or no smoking.

Few side effects, including mouth and throat irritation and dry cough, were seen, mostly at the beginning of the study; they were not present at study completion.

In summary, this small clinical trial from Italy demonstrates that use of e-cigarettes resulted in smoking reduction or elimination in 55% of smokers who did not intend to quit.  The evidence base is solid and growing.

Wednesday, October 24, 2012

Low Trace Metal Levels in American Smokeless Tobacco Products Mean No Significant Health Risk

I previously discussed a comprehensive chemical analysis of smokeless tobacco products conducted by M.F. Borgerding and colleagues at RJ Reynolds Tobacco Company and published in Regulatory Toxicology and Pharmacology (abstract here).  I focused on the results for tobacco-specific nitrosamines in that post (link here). 

Borgerding and colleagues analyzed many other agents, including trace metals.  As they write, “Human exposure to toxic trace metals occurs from a variety of sources that include diet, the environment, vitamin and dietary supplements, tobacco and tobacco smoke, among others.”  They measured levels of cadmium, arsenic, nickel, chromium and lead.

The diet is a prominent source of trace metals, so it is reasonable to compare the exposures to these metals from smokeless tobacco to those from the diet.  I will use a series of reports from the European Food Safety Authority (EFSA) for these comparisons.  I will report the metal levels in smokeless tobacco products as micrograms (ug) per gram (g) of tobacco, in dry weight.  I will compare the exposure from using one can of moist snuff per day (about 15 g of tobacco, dry) with daily dietary exposure.

It is important to note that this discussion will deal only with exposure, which is the amount of a substance that is contained in food or other products that we consume.  The other factor is uptake, which is the amount that we absorb.  Substances have a broad range of absorption rates; the absorption rate from food traveling through the gastrointestinal tract may be different from that of a smokeless tobacco product held in the lip. 

The absorption rate of trace metals from smokeless tobacco is not known, but a general idea is provided by studies that have estimated the percentage of nicotine absorbed from these products.  A study that I discussed recently (here) estimated that one-quarter to one-third of the nicotine in Swedish snus is delivered to the user.  That is a good place to start with respect to the potential absorption of other agents.  


Cadmium occurs naturally in the environment; for nonsmokers, the diet is the dominant source of this contaminant.  It is potentially toxic to the kidneys, and is listed by the International Agency for Research on Cancer (IARC) as a carcinogen, primarily based on lung cancer after inhalation by workers in high-exposure industries (here).   

The EFSA reports that dietary exposure is 19.5 ug (here).  Borgerding reports that moist snuff contains cadmium at a level of 1.05 ug/g.  Thus, a user of one can per day is exposed to 15.8 ug of cadmium, or about 80% of the dietary level.  This combined exposure is only one-half of the 70 ug that the World Health Organization suggests as a safe daily cadmium intake (reported in this article). 

A recent analysis of federal data revealed that smokeless tobacco users do not have elevated blood or urine cadmium levels compared with nonusers of tobacco (abstract here).  In that study cigarette smokers have elevated cadmium levels.


Arsenic also occurs naturally in the environment, and is present in a variety of forms (here).  IARC lists arsenic as a cause of urinary bladder, lung and skin cancers, based on studies of high levels of the metal in drinking water (hundreds to thousands of ug per liter)(here).  The World Health Organization guideline recommends that level of arsenic in drinking water not exceed 10 ug per liter.   

The EFSA reports that dietary exposure is 56 ug per day (here).  Borgerding reports that moist snuff contains arsenic at a level of 0.21 ug/g, meaning that a one-can-per-day user is exposed to 3.2 ug of arsenic, or about 6% of the dietary exposure. 


Nickel alloys and compounds have been produced commercially for over 100 years. IARC lists some nickel compounds as a cause of lung and nasal cancers, based on workers in these industries who were exposed to massive quantities by inhalation (here).  In comparison, everyone else is exposed to vanishingly small quantities of nickel, mainly from food and water, and there is no evidence of health risks at this level.

The EFSA reports that dietary exposure to nickel is 150 ug/day (here).  Borgerding observes that moist snuff contains nickel at a concentration of 2.05 ug/g.  Thus, a one-can-per-day user is exposed to about 31 g, or roughly 21% of the dietary exposure.       


As with nickel, metal workers who were exposed to massive quantities of some chromium compounds developed lung cancer, resulting in IARC classification of chromium as a carcinogen (here).  However, there is little evidence that much lower exposure from food and water is problematic. 

Chromium is, in fact, an essential micronutrient. The recommended daily allowance is 35 ug for adult men and 25 ug for adult women (here).  Borgerding advises that moist snuff contains chromium at a concentration of 1.6 ug/g, so one can provides about 24 ug.


Lead occurs naturally in the environment, but exposures were elevated in the last century due to its use in water pipes, paint and gasoline.  However, lead is no longer used for these purposes, making diet the primary source for most people.  Because lead affects the developing nerve system, exposure among children is of particular concern.  Although numerous studies have focused on workers exposed to massive quantities of lead, links to cancer are not conclusive; IARC lists lead as a probable carcinogen (here).

The EFSA reports that dietary exposure to lead is 41 ug/day (here).  Borgerding notes that moist snuff contains lead at a concentration of 0.32 ug/g.  A one-can-per-day user is exposed to about 6.1 ug, or 21% of the dietary exposure.      

In summary, exposure to cadmium, arsenic, nickel, chromium and lead from moist snuff is much lower than that from a typical diet.  Although all of these metals cause cancer in workers and others with massive exposures, levels from the diet and moist snuff are vastly lower and present no significant health risks.

Wednesday, October 17, 2012

Canada’s Health Department, Health Canada: Favorable to Marijuana Vapor But Bans E-Cigs

Since 2009, Health Canada has blocked importation, advertising and sales of nicotine vapor systems, including e-cigarettes (here).  Yet the agency has published a supportive comment about vapor delivery systems for tetrahydrocannabinol (THC), the active ingredient in marijuana.

The following appears on a Health Canada webpage for health professionals (here):

“The advantages of vaporization apparently include the formation of a smaller quantity of toxic by-products such as carbon monoxide, polycyclic aromatic hydrocarbons (PAHs) and tar, as well as a more efficient extraction of THC from the cannabis material. The subjective effects and plasma concentrations of THC are comparable to those of smoked cannabis with absorption being somewhat faster with the vaporizer. The vaporizer is well-tolerated, with no reported adverse effects, and is generally preferred over smoking by most subjects...”

Among the comment’s scientific references, the most frequently cited is a study of vaporized marijuana published in 2007 by scientists at the University of California at San Francisco (abstract here).  It concluded:

“Whereas smoking marijuana increased [carbon monoxide, CO] levels as expected for inhalation of a combustion product, there was little if any increase in CO after inhalation of THC from the vaporizer. This indicates little or no exposure to gaseous
combustion toxins. Combustion products are harmful to health and reflect a major concern about the use of marijuana cigarettes for medical therapy as expressed by the Institute of Medicine… Vaporization of marijuana does not result in exposure to combustion gases, and therefore is expected to be much safer than smoking marijuana cigarettes. The vaporizer was well tolerated and preferred by most subjects compared to marijuana cigarettes.”

Even more interesting, the senior author of this study was Dr. Neal Benowitz, who currently serves on the FDA Tobacco Products Scientific Advisory Committee.  It is perplexing that Dr. Benowitz has taken a rational and scientific position with respect to a “much safer” (his words) delivery system for marijuana, but his position on tobacco is entirely prohibitionist (as I have documented here and here). 

The conclusion by Dr. Benowitz and Health Canada that marijuana vaporization is vastly safer than combustion is perfectly applicable to e-cigarettes versus conventional cigarettes.  If vaporization is safer than combustion, why do they deny smokers a product that could save hundreds of thousands of lives in the U.S. and Canada?

Given the agency’s charter, that it is “responsible for helping Canadians maintain and improve their health, while respecting individual choices and circumstance,” Health Canada is failing in its mission as it caters to the unfounded bias of tobacco prohibition forces.

Wednesday, October 10, 2012

Tobacco-Free Kids: Don’t Tell Oklahoma Smokers the Truth

On October 3 I testified at an Oklahoma legislative hearing on tobacco harm reduction, providing the state’s smokers and policymakers with the facts about vastly safer smoke-free cigarette substitutes. My op ed column on the subject was published in The Oklahoman on September 30 (available here). 

In response, an October 10 commentary by Danny McGoldrick (here) urged lawmakers not to inform Oklahoma smokers about safer products. 

McGoldrick argued “there’s little evidence that this tobacco industry scheme reduces smoking.  In fact, there is considerable risk it would backfire and encourage more tobacco use, including among children. The result would be more tobacco-caused death and disease.”

That these unsubstantiated, demonstrably false claims are made by a vice president for research at a national anti-tobacco group is appalling, but not unexpected.  McGoldrick’s employer, the Campaign for Tobacco-Free Kids, like other tobacco prohibitionist groups, routinely ignores scientific evidence that doesn’t support their objective.  Rather, they offer conjecture, unfounded assertions and ad hominem attacks.

The scientific foundation for tobacco harm reduction is well established by decades of research.  My comprehensive reviews of the evidence in 2006 (here) and 2011 (here) were based on 279 articles published primarily in medical and scientific journals.  Numerous articles have been published in the past year.

McGoldrick ignores this evidence.  Instead, he repeats an unsupported claim about marketing to children.  Tobacco initiation by young people should be stopped, but offering adult smokers safer products is not a children’s issue.  If Tobacco-Free Kids has evidence that tobacco manufacturers are marketing to children, they should present it to states’ attorneys general.  The 1998 Master Settlement Agreement prohibits manufacturers from targeting children, and many states have expedited processes for policing and enforcing these provisions. 

McGoldrick’s group and its allies have made significant strides in pushing the FDA to stifle promotion of smoke-free products. In March of this year, the agency released a 50-page draft document listing information that will be required for a product to be accepted as “modified [i.e., reduced] risk” (available here).  If adopted, these overly burdensome requirements will condemn smokeless tobacco products, and therefore tobacco harm reduction, to regulatory purgatory (here).

For Tobacco-Free Kids, wrecking the tobacco industry is more important than saving smokers’ lives.  Discouraging the education of smokers about safer products contributes to the 440,000 smoking-attributable deaths recorded in the U.S. annually.  Public policy should support healthier choices for all Americans, including those addicted to nicotine.

Thursday, October 4, 2012

More Evidence That Smokeless Tobacco Products in the U.S. Have Low TSNA Levels

New data shows that tobacco-specific nitrosamines (TSNAs) were at very low levels in almost all popular smokeless products available in the U.S. in 2006 and 2007. The findings appear in a research article in Regulatory Toxicology and Pharmacology (abstract here) authored by M.F. Borgerding and other scientists at RJ Reynolds Tobacco Company.

TSNA levels for specific brands are listed in the table below.  In reviewing the data, one should consider these points:

1.  The table lists levels in parts per million (ppm) by weight, or micrograms of TSNAs per gram of dry product.  This allows products with different moisture levels (e.g., dissolvable tobacco at 4% and moist snuff at about 50%) to be compared directly.

2.  ALL of the American products had low TSNA levels, especially when compared to products from the 1970s and 1980s (described here).  In the early 1980s, it was common to see moist snuff products with TSNA levels at 40-80 ppm; by the end of the decade, most products were under 40 ppm.  With rates declining further, to around 20 ppm in 1995, analytic reports ceased.

3.  Several Swedish snus products were analyzed; all had TSNA levels below 2 ppm. 

4.   The lowest TSNA levels were found in Ariva (0.1 ppm) and Stonewall (0.4 ppm) dissolvable tobacco pellets made by Star Scientific, Inc. (here). 

5.  Chewing tobacco products all had levels below the Gothiatek standard, which is 10 parts per million.  Gothiatek was developed by Swedish Match in the late 1990s to serve as a voluntary standard for maximum levels of some contaminants (described here).

6.  The highest TSNA levels (12-41 ppm) were found in powdered dry snuff, a form of tobacco historically favored by older Southern women, but steadily declining in popularity (evidence here).  When I worked with an investigator at the Swedish National Food Administration to analyze TSNAs in American products in 2003, we found very high levels in two powdered dry snuff brands ( abstract here).

How do smokeless tobacco TSNA levels compare with those in cigarettes?  The Reynolds scientists did not test cigarettes, but I did.  Camel and Marlboro cigarettes had TSNA levels around 7 ppm in 2003, putting them in the same range as many moist snuff and chewing tobacco products.  However, TSNAs are but one of many thousands of toxins delivered in smoke, so comparing these agents in cigarettes and smokeless is almost meaningless.  

A National Cancer Institute fact sheet describes TSNAs as “the most harmful chemicals in smokeless tobacco…” (here), but this study shows that TSNAs are present in tiny concentrations.  As discussed in a previous post (here), there is virtually no evidence that current TSNA levels are associated with any measurable cancer risks.

TSNA Levels in Smokeless Tobacco Products in the U.S., 2006 and 2007
Product Parts Per Million
Dissolvable Tobacco
Chewing Tobacco
Beech Nut2.9
Levi Garrett5.2
Red Man1.8
Red Man Golden1.2
Stoker Chew Apple4.6
Taylor’s Pride8.3
Traditional Moist Snuff
Cooper LC WG35.7
Copenhagen LC9.7
Copenhagen Pouches9.9
Grizzly LC WG 200610.1
Grizzly LC WG 20079.0
Husky FC11.2
Kayak LC WG25.5
Kodiak WG 200611.9
Kodiak WG 200713.1
Longhorn LC WG7.6
Red Seal FC10.0
Renegades WG7.9
Skoal FC Original10.0
Skoal LC Cherry9.1
Skoal LC Mint10.5
Skoal LC Straight10.4
Skoal LC WG13.9
Timberwolf LC WG8.1
Snus and Snus-Style Snuff
Camel Frost 20061.8
Camel Frost 20072.3
Camel Original 20061.9
Camel Original 20072.5
Camel Spice 20061.8
Camel Spice 20072.1
Catch Dry Eucalyptus*1.4
Catch Dry Licorice*1.4
General Portion*1.6
General White Portion*1.3
Skoal Dry2.7
Taboka Green1.6
Powdered Dry Snuff
Dental Sweet41.0
Levi Garrett25.8
Railroad Mills27.2
Red Seal18.6
*Manufactured in Sweden
LC- long cut
FC- fine cut