The health risks of e-cigarettes are not known for certain, but the risk of serious adverse events is thought to be low, and e-cigarettes are likely safer than combusted tobacco products. With professional help, they can help people quit smoking. Less serious adverse effects include abdominal pain, headache, blurry vision, throat and mouth irritation, vomiting, nausea, and coughing. Nicotine is addictive and harmful to fetuses, children and young people. In 2019 and 2020, an outbreak of severe vaping lung illness in the US was strongly linked to vitamin E acetate by the CDC. E-cigarettes produce similar levels of particulates to tobacco cigarettes. There is "only limited evidence showing adverse respiratory and cardiovascular effects in humans", with the authors of a 2020 review calling for more long-term studies on the subject. E-cigarettes increase the risk of asthma by 40% and chronic obstructive pulmonary disease by 50% compared to not using nicotine at all. Pregnancy The Royal College of Midwives states, "While vaping devices such as<unk> s (e-cigs) do contain some toxins, they are at far lower levels than found in tobacco smoke. If a pregnant woman who has been smoking chooses to use an e-cig and it helps her to quit smoking and stay smokefree, she should be supported to do so." Based on the available evidence on e-cigarette safety, there was also "no reason to believe that use of an e-cig has any adverse effect on breastfeeding." The statement went on to say, "vaping should continue, if it is helpful to quitting smoking and staying smokefree". The UK National Health Service says: "If using an e-cigarette helps you to stop smoking, it is much safer for you and your baby than continuing to smoke." Many women who vape continue to do so during pregnancy because of the perceived safety of e-cigarettes compared to tobacco. United States In one of the few studies identified, a 2015 survey of 316 pregnant women in a Maryland clinic found that the majority had heard of e-cigarettes, 13% had used them, and 0.6% were current daily users. These findings are of concern because the dose of nicotine delivered by e-cigarettes can be as high or higher than that delivered by traditional cigarettes. Data from two states in the Pregnancy Risk Assessment System (PRAMS) show that in 2015—roughly the mid-point of the study period—10.8% of the sample used e-cigarettes in the three months prior to the pregnancy while 7.0%, 5.8%, and 1.4% used these products at the time of the pregnancy, in the first trimester, and at birth respectively. According to National Health Interview Survey (NHIS) data from 2014 to 2017, 38.9% of pregnant smokers used e-cigarettes compared to only 13.5% of non-pregnant, reproductive age women smokers. A health economic study found that passing an e-cigarette minimum legal sale age law in the United States increased teenage prenatal smoking by 0.6 percentage points and had no effect on birth outcomes. Nevertheless, additional research needs to be done on the health effects of<unk>  use during pregnancy. According to the CDC, E-cigarettes are not safe during pregnancy. "Although the aerosol of e-cigarettes generally has fewer harmful substances than cigarette smoke, e-cigarettes and other products containing nicotine are not safe to use during pregnancy. Nicotine is a health danger for pregnant women and developing babies and can damage a developing baby's brain and lungs. Also, some of the flavorings used in e-cigarettes may be harmful to a developing baby." Harm reduction Effects of vaping, compared to alt=Switching from tobacco to vaping may reduce weight gain after smoking cessation, increase exercise tolerance, reduce exposure to toxic chemicals, and reduce risk of death. Vaping may reduce shortness of breath, reduce coughing, reduce spitting, and reduce sore throat compared to tobacco. Harm reduction refers to any reduction in harm from a prior level. Harm minimization strives to reduce harms to the lowest achievable level. When a person does not want to quit nicotine, harm minimization means striving to eliminate tobacco exposure by replacing it with vaping. E-cigarettes can reduce smokers' exposure to carcinogens and other toxic chemicals found in tobacco. Tobacco harm reduction has been a controversial area of tobacco control. Health advocates have been slow to support a harm reduction method out of concern that tobacco companies cannot be trusted to sell products that will lower the risks associated with tobacco use. A large number of smokers want to reduce harm from smoking by using e-cigarettes. The argument for harm reduction does not take into account the adverse effects of nicotine. There cannot be a defensible reason for harm reduction in children who are vaping with a base of nicotine. Quitting smoking is the most effective strategy to tobacco harm reduction. Tobacco smoke contains 100 known carcinogens and 900 potentially cancer-causing chemicals, but e-cigarette vapor contains less of the potential carcinogens than found in tobacco smoke. A study in 2015 using a third-generation device found levels of formaldehyde were greater than with cigarette smoke when adjusted to a maximum power setting. E-cigarettes cannot be considered safe because there is no safe level for carcinogens. Due to their similarity to traditional cigarettes, e-cigarettes could play a valuable role in tobacco harm reduction. However, the public health community remains divided concerning the appropriateness of endorsing a device whose safety and efficacy for smoking cessation remain unclear. Overall, the available evidence supports the cautionary implementation of harm reduction interventions aimed at promoting e-cigarettes as attractive and competitive alternatives to cigarette smoking, while taking measures to protect vulnerable groups and individuals. The core concern is that smokers who could have quit entirely will develop an alternative nicotine addiction. Dual use may be an increased risk to a smoker who continues to use even a minimal amount of traditional cigarettes, rather than quitting. The promotion of vaping as a harm reduction aid is premature, while a 2011 review found they appear to have the potential to lower tobacco-related death and disease. Evidence to substantiate the potential of vaping to lower tobacco-related death and disease is unknown. The health benefits of reducing cigarette use while vaping is unclear. E-cigarettes could have an influential role in tobacco harm reduction. The authors warned against the potential harm of excessive regulation and advised health professionals to consider advising smokers who are reluctant to quit by other methods to switch to e-cigarettes as a safer alternative to smoking. A 2014 review recommended that regulations for e-cigarettes could be similar to those for dietary supplements or cosmetic products to not limit their potential for harm reduction. A 2012 review found e-cigarettes could considerably reduce traditional cigarettes use and they likely could be used as a lower risk replacement for traditional cigarettes, but there is not enough data on their safety and efficacy to draw definite conclusions. There is no research available on vaping for reducing harm in high-risk groups such as people with mental disorders. A 2014 PHE report concluded that hazards associated with products currently on the market are probably low, and apparently much lower than smoking. However, harms could be reduced further through reasonable product standards. The British Medical Association encourages health professionals to recommend conventional nicotine replacement therapies, but for patients unwilling to use or continue using such methods, health professionals may present e-cigarettes as a lower-risk option than tobacco smoking. The American Association of Public Health Physicians (AAPHP) suggests those who are unwilling to quit tobacco smoking or unable to quit with medical advice and pharmaceutical methods should consider other nicotine-containing products such as e-cigarettes and smokeless tobacco for long-term use instead of smoking. A 2014 WHO report concluded that some smokers will switch completely to e-cigarettes from traditional tobacco but a "sizeable" number will use both. This report found that such "dual-use" of e-cigarettes and tobacco "will have much smaller beneficial effects on overall survival compared with quitting smoking completely." Smoking cessation The use of e-cigarettes for quitting smoking is controversial. Limited evidence suggests that e-cigarettes probably do help people to stop smoking when used in clinical settings. However, according to a review article by Hussein Traboulsi et al. in May of 2020, a study by Dr Peter Hajek also resulted in more smokers becoming dual users than succeeded in complete abstinence; "Nonetheless, the continued use of and dependence on nicotine and the creation of dual users were issues in this trial...Additionally, while 18% of the e-cigarette users achieved complete abstinence, 25% (110/438) became dual users of e-cigarettes and conventional cigarettes." Data regarding their use includes at least 26 randomized controlled trials and a number of user surveys, case reports, and cohort studies. At least once recent review (2019) found that vaping did not seem to greatly increase the odds of quitting smoking. As a result of the data being confronted with methodological and study design limitations, no firm conclusions can be drawn in respect to their efficacy and safety. A 2016 review found that the combined abstinence rate among smokers using e-cigarettes in prospective studies was 29.1%. The same review noted that few
Electronic cigarette
Herbal cigarette
Ventilated cigarette
Roll-your-own cigarette
Cigarette
Herbal smokeless tobacco
Dissolvable tobacco
Smokeless tobacco