On July 27, the latest paper released by researchers from the Centers for Disease Control and Prevention (CDC) showed that e-cigarette users have extremely low levels of the tobacco-specific nitrosamine (TSNA) metabolite NNAL in their urine, only 2.2% of tobacco user and 0.6% of smokeless tobacco users (snuff, chewing tobacco, etc.).

The research results once again proved that e-cigarettes are far less harmful than traditional tobacco, and e-cigarettes do not have the second-hand smoke problem of traditional tobacco.

More than 70 carcinogens have been identified in traditional tobacco and second-hand smoke. Among them, tobacco-specific nitrosamines (TSNA) are the most important carcinogens in tobacco and the smoke produced by combustion, which are extremely harmful to the health of smokers and second-hand smokers. Big. TSNA includes NNK, NNN, NAB, NAT, etc. The World Health Organization (WHO) has determined that NNK and NNN are the main factors causing the carcinogenicity of cigarette smoke.

The study lasted for 7 years. Since 2013, it has collected related epidemiological data on tobacco usage behavior, including use methods, attitudes, habits, and health effects, and used this to evaluate the impact of US Food and Drug Administration (FDA) related tobacco regulatory policies. This paper is the first phase of the study. It mainly monitors the NNAL concentration in the urine of the experimenters in the first wave (W1) of the PATH study conducted from September 12, 2013 to December 15, 2014.

vape research

                                        From: Screenshot of the latest paper published by CDC researchers

NNAL is a metabolite produced when the human body processing nitrosamines (TSNAs), which is excreted through the urine. People inhale nitrosamines (TSNA) through the use of tobacco products or secondhand smoke, and then excrete the metabolite NNAL through the urine.

The results of the study showed that the average urine NNAL concentration of smokeless tobacco users was 993.3 ng/g creatinine, cigarette users were 285.4 ng/g creatinine, and e-cigarette product users were 6.3 ng/g creatinine, which means the nitrosamine metabolite NNAL in urine of e-cigarette users is only 2.2% of cigarette users and 0.6% of smokeless tobacco users.

This study is not the first time that CDC has published evidence that second-hand smoke problem of traditional tobacco does not exist in e-cigarettes. As early as 2014, CDC researchers published a research paper about the study on VOCs (volatile organic compounds) in the smoke of traditional tobacco and e-cigarettes, which showed that the levels of VOCMs of VOCs metabolites in the urine of e-cigarette users are comparable to people who has never smoked. Then the concentration of VOCMs in smokers is significantly higher than that of e-cigarette users, smokeless tobacco users and people who has never smoked. VOCMs are metabolites produced when the human body processing VOCs and are excreted through urine.


VOCs (Volatile Organic Compounds) is a general term for organic compounds that are volatile under certain conditions. The commonly known harmful substances such as benzene, toluene, and formaldehyde belong to the category of VOCs.

TSNA (nitrosamines) and VOCs (volatile organic compounds) are two most important carcinogens in second-hand smoke of traditional tobacco. The above-mentioned CDC research proves that e-cigarettes do not have the same second-hand smoke problems as traditional tobacco.

This also shows once again that conflating e-cigarettes with traditional tobacco, and even regarding the harm of second-hand smoke of traditional tobacco as the evidence that e-cigarettes should be included in the category of indoor tobacco control, lacks scientific basis and is absurd.