David Hammond, assistant professor of health studies and gerontology at the University of Waterloo, assesses the Massachusetts report on nicotine yields (PDF). He writes:

1. I am somewhat dismayed by the language used in the report. The first bulleted point in the report states that, "the total amount of nicotine delivered to the smoker has increased significantly." This is factually incorrect. The report did not measure nicotine delivery to smokers. This involves measuring biomarkers of uptake in a biosample such as urine, blood, or saliva. The most fundamental point that should be made in the report or in any media coverage is that cigarette yields –regardless of whether they are tested using the FTC, Massachusetts, or Canadian testing methods—are NOT associated with human exposure or delivery. (Note: I have attached a paper that was published this past month and makes this point directly with regards to the Massachusetts method.) [Emphasis by the author.]

In the background information on page 6, the report makes another inaccurate statement: "Nicotine yield is a measure of the amount of nicotine in the smoke that a smoker inhales." This is simply incorrect. Smokers of the same product inhale significantly different amounts of nicotine from the same cigarettes. This has been demonstrated over and over, including in population-based studies.

To be fair, the report certainly makes an attempt to present the relevant context on emissions. However, the misleading terms used in the executive summary and elsewhere get the fundamental point wrong and only perpetuate the misconception that the emission levels from machine smoking are associated with human exposure. If nothing else, the report is an excellent illustration of the confusion on this fundamental issue, even among well-intentioned and progressive tobacco control agencies. It is no surprise, therefore, that many consumers continue to believe that "lower tar" cigarettes are also reduced exposure/risk products.

2. The report indicates that, "The MDPH [Massachusetts Department of Public Health] testing method better simulates the smoking behavior of the typical smoker under typical smoking conditions." Unfortunately, this isn't entirely the case. It is true that the MDPH method provides more intense measures of smoking behaviour, but it does not "mimic" human smoking behaviour. The most fundamental aspect of human smoking behaviour is that it is compensatory. In other words, humans adjust the intensity of their smoking in response to the cigarette design and emission level. Therefore, "lower nicotine" yield cigarettes are smoked systematically more intensely. The MDPH testing method is no better at "mimicking" this aspect of human smoking than the FTC method.

3. In my view, perhaps the most important point to communicate is the following: "For all brands tested in both 1998 and 2004, there were no significant differences in the total nicotine content between 'full flavor,' 'medium,' 'mild,' 'light,' or 'ultra-light' cigarettes." Cigarettes have been designed to be "elastic" or "compensatible," and there is more than enough nicotine available in any of the products to promote and sustain addiction. Moreover, the modern cigarette has been designed to present the smoke to consumers in a palatable manner that minimizes the irritation and unpleasantness of inhaling smoke. In this sense, the modern cigarette design is no less harmful or less addictive than brands from 50 years ago, and perhaps even more so.

4. The primary design feature used to reduce emissions under the FTC and the MDPH method is filter ventilation. The report notes the range in filter ventilation levels, which appeal to different segments of the market, and appear to give smokers a "choice" or range of nicotine and tar levels. This range helps to reinforce the misconception that switching to "lower emission" products confers some advantage. As indicated above, smokers compensate for more highly ventilated cigarettes. In some cases, smokers cover the vent holes either intentionally or unintentionally, although the most common means of compensation is simply to change the intensity of puffing behaviour. (The report only mentions vent-hole blocking, which is an oversight.)

5. The terms "light", "ultra-light" etc, are merely brand descriptors that are decided upon by manufacturers. There is a strong association between the tar/nicotine emissions and the descriptors (i.e. "ultra light" brands typically have lower tar and nicotine emissions), but they are arbitrary marketing descriptors. Although there are conventions for classifying the tar emission levels of different descriptors, there is no "official" categorization and the same categories do not necessarily apply in different markets. (i.e. an "ultra-light" cigarette in China, may have a similar tar level as a "light" or even a full flavour brand. There are also examples of this happening within a market.)

6. The current recommendation from the WHO and other expert panels is not to communicate emission information directly to consumers, regardless of the testing method. Emission information can help scientists and regulators to learn about product design, but it is useless to the individual consumer. Expert groups also recommend removing the deceptive "light/mild" descriptors. The European Union has already banned these descriptors, as have other countries.

7. Why have the MDPH emissions increased? I'm not sure. Without the data it's hard to get a sense of brand specific changes and general market trends. Some of the increases would suggest design changes, although many of the differences appear to be relatively modest. At first blush, the changes don't appear to signal any significant change in cigarette design across the market, but I really couldn't say based on the report summary.

8. So, in conclusion, is the increase in MDPH nicotine emissions worrisome? Not beyond the fact that it illustrates that manufacturers continue to manipulate emissions levels to appeal to different market segments and to ensure that cigarettes are as appealing to consumers as possible. We should not interpret a 10% reduction in nicotine emissions as a decrease in addictive potential; thus, we should not interpret cigarettes with a 10% increase as more addictive. Any suggestion that the brands in 2005 are more addictive than the 1998 studies would require much more evidence than the changes in emission levels depicted in the report. Indeed, I would not argue that the modern cigarette is any less addictive than the 1950's cigarette despite the fact they cigarettes in the 1950's had many more times the nicotine emission levels than current brands. Cigarettes remain both incredibly addictive and lethal, and manufacturers have designed cigarettes to produce deceptively low nicotine readings on the standard test while delivering more than enough nicotine to create and sustain addiction. The MDPH report makes this important point, although regulators and the public health community must be cautious about placing too much important on changes in emission levels without corresponding data on human patterns of use and actual measures of exposure.