- Friday, 04 September 2015 16:40
By Dr Farsalinos
Nothing surprises me anymore in the field of e-cigarette research, debate and media campaigns which predominantly misinform and distort the truth. This time, the Center for Environmental Health (CEH) has made headline announcements about tests they performed on e-cigarettes, finding the “cancer-causing chemicals” formaldehyde and acetaldehyde. The story has been presented as a new shocking and breakthrough discovery about how bad e-cigarettes are.
CEH has released a report saying they tested several brands of e-cigarettes under “realistic conditions of use”. They say that they found levels much higher than the limits set by Proposition 65 California’s consumer protection law. They do not mention a single sentence on how they performed the testing, they do not mention how “realistic conditions of use” were defined and they do not mention a single number (amounts of formaldehyde and acetaldehyde found) or how they made the calculations (daily exposure? based on how many puffs per day?). Despite that, the CEH CEO was more than willing to go on TV, and present pseudo-dilemmas about how being hit by a car is not any better than being hit by a bus and other colorful but misleading and unscientific claims.
The truth is that we know for several years that e-cigarettes when heated can release aldehydes such as formaldehyde and acetaldehyde. CEH cites the research letter published in New England Journal of Medicine (finding 5-15 times higher levels of formaldehyde in e-cigarettes compared to tobacco cigarettes), which was recently challenged by our study published in Addiction (which did not fit to CEH tactics to mention it). CEH used the California-defined limits for formaldehyde exposure, which is 40 ug per day. In our study in Addiction, we found 11.3 ug formaldehyde per 10 puffs under normal vaping conditions (no overheating). Thus, the California limit would be exceeded by taking just 40 puffs per day. However, in our paper we mentioned that our findings probably do not represent any meaningful risk for consumers. This was based on the fact a recent toxicological review found that a limit of 100 ppb (125 ug/m3) “should protect even particularly susceptible individuals from both irritation effects and any potential cancer hazard”. This means that a total daily exposure of 2500 ug (20m3 is the average daily breathing volume) is safe (> 2500 e-cigarette puffs per day). The WHO has calculated that the average daily exposure to formaldehyde is 500-1100 ug/day (300-600 ug at home, 200-500 ug at work, excluding occupational exposure to sources of formaldehyde). According to the WHO criteria, formaldehyde emissions from e-cigarettes are not different from levels found in the environment! The WHO mentions: “To prevent significant sensory irritation in the general population, an air quality guideline value of 0.1 mg/m3 as a 30-minute average is recommended. Since this is over one order of magnitude lower than a presumed threshold for cytotoxic damage to the nasal mucosa, this guideline value represents an exposure level at which there is a negligible risk of upper respiratory tract cancer in humans”. In any case the formaldehyde emissions from e-cigarettes are at least 7 times lower compared to tobacco cigarettes (as we found in our study in Addiction), and comparing their risk as if being hit by a car instead of a bus is a misleading claim with the only purpose of misinforming.
Formaldehyde is linked with nasopharyngeal but not lung cancer. However, there is a lot of dispute on whether this is accurate. Moreover, formaldehyde is naturally formed in the body of every human and is exhaled at levels of 1-10 ug/m3 or even more. The American Chemistry Council (ACC) and the National Academy of Sciences have criticized the risk assessment of formaldehyde exposure, presenting the paradox that “every human breath poses an unacceptable risk of cancer” based on such assessments.
For acetaldehyde, I am not going to comment on their findings. I am just going to say that the IARC has classified acetaldehyde as a possible carcinogen (group 2B), because no study has found acetaldehyde to produce cancer in humans through inhalation (there are only data on animals). It is a Group 1 carcinogen ONLY when produced by metabolism of ethanol, associated with alcohol drinking. Of note, the California limits for acetaldehyde are 90 ug/day, while the smoke of 1 tobacco cigarette contains more than 1000 ug acetaldehyde. In our study, we found 4.5 ug acetaldehyde per 10 puffs of e-cigarettes.
In conclusion, CEH has been engaged into a media campaign against e-cigarettes without providing any valuable information in their report. There is no information on how the devices were tested, how “realistic use conditions” were defined, how daily exposure was calculated and if background environmental levels were assessed and deducted from the results. They are using the limits set by California Proposition 65, which also contains chemicals that are released through the exhaled breath of healthy humans. The data are irrelevant to the realistic carcinogenic potential of e-cigarettes, which of course is incomparable to the risk of tobacco cigarettes. I have received many emails and social media messages from e-cigarette users, who are once again alarmed by “cancer risks” from e-cigarettes heard over the media. I hope none relapses to smoking after witnessing yet another campaign exaggerating and mis-presenting the risks associated with e-cigarette use.