Electronic cigarette
First generation electronic cigarette resembling a tobacco cigarette
Second generation types of electronic cigarettes
The
benefits and risks of electronic cigarette use are uncertain. The limited evidence suggests that e-cigarettes are probably safer than traditional
cigarettes. The data is inconclusive on using e-cigarettes as a
smoking cessation aid.
[5] Their role in
tobacco harm reduction as a substitute for
tobacco products is unclear.
[7] They may possibly be as safe as other
nicotine replacement products, but there is not enough data to draw conclusions.
[8][9] The evidence suggests that the US
Food and Drug Administration (FDA) accepted products such as a
nicotine inhaler may be a safer way to give nicotine.
Electronic cigarettes may carry a risk of addiction in those who do not already smoke,
but there is no evidence of ongoing use among those who have never smoked.
They may promote delaying of
quitting smoking, or act as a deterrent to quitting
. Emissions from e-cigarette may contain tiny
ultrafine particles of flavors, aroma transporters, glycerol, propylene glycol, nicotine, tiny amounts of
carcinogens and
heavy metals, and other chemicals. The evidence indicates the levels of contaminants do not warrant health concerns according to workplace safety standards
. E-cigarette emissions have fewer
toxic components than cigarette smoke. They are likely to be less harmful to users and bystanders. Less serious
adverse effects from e-cigarette use include throat and mouth inflammation, vomiting, nausea, and cough.
The frequency of use has increased with up to 10% of American high
school students having ever used them as of 2012 and around 3.4% of
American adults as of 2011.
In the UK the number of e-cigarette users has increased from 700,000 in
2012 to 2.1 million in 2013. About 60% are smokers and most of the rest
are ex-smokers.
E-cigarette users most commonly continue to smoke traditional cigarettes
. Current e-cigarettes arose from an invention made by
Hon Lik in China in 2003, and devices are mostly manufactured in China.
E-cigarette brands have increased advertising with similar marketing to that used to sell cigarettes in the 1950s and 1960s.
Because of the possible relationship to tobacco laws and medical drug policies,
electronic cigarette legislation is being debated in many countries.
[3][16] The
European Parliament
passed regulations in February 2014 requiring standardization of
liquids and personal vaporizers, listing of ingredients, and
child-proofing of liquid containers. The United States
Food and Drug Administration (FDA) published proposed regulations in April 2014 with some similar measures.
[17]
Health effects
Position of medical organizations
As
of 2014 electronic cigarettes have not been approved for helping people
quit smoking by any government. In July 2014, a report produced by the
World Health Organization (WHO) for the Conference of the Parties to the
WHO Framework Convention on Tobacco Control,
found there was not enough evidence to determine if electronic
cigarettes can help people quit smoking. It suggested that smokers
should be encouraged to use approved methods for help with quitting.
But the same report also mentioned expert opinions in scientific papers
that suggested e-cigarettes may have a role helping people quit who
have failed using other methods.
A previous WHO statement from July 2013 stated that e-cigarettes have
not been shown to be effective helping people quit smoking. It also
recommended that "consumers should be strongly advised not to
use" e-cigarettes unless a reputable national regulatory body has found
them safe and effective. The
World Lung Foundation
applauded the 2014 WHO report's recommendation for tighter regulation
of e-cigarettes due to concerns about the safety of e-cigarettes and the
possible increased nicotine or tobacco addiction among youth.
The UK
National Health Service
has concluded, "While e-cigarettes may be safer than conventional
cigarettes, we don’t yet know the long-term effects of vaping on the
body. There are clinical trials in progress to test the quality, safety
and effectiveness of e-cigarettes, but until these are complete, the
government can’t give any advice on them or recommend their use."
In 2014, the US
Food and Drug Administration
(FDA) concluded, "E-cigarettes have not been fully studied, so
consumers currently don’t know: the potential risks of e-cigarettes when
used as intended, how much nicotine or other potentially harmful
chemicals are being inhaled during use, or whether there are any
benefits associated with using these products. Additionally, it is not
known whether e-cigarettes may lead young people to try other tobacco
products, including conventional cigarettes, which are known to cause
disease and lead to premature death."
Smoking cessation
As of 2014, research on the safety and efficacy of e-cigarette use for smoking cessation is limited.Their benefit in helping people quit smoking is uncertain and has not been convincingly demonstrated.
A 2014 review found no evidence confirming e-cigarettes as a more
effective aid than existing FDA-compliant nicotine replacement
treatments for smoking cessation.The same review found that to encourage e-cigarette use as a cessation aid in cigarette users is premature.
A 2013
randomized controlled trial
found higher smoking cessation rates associated with e-cigarettes with
nicotine than e-cigarettes without nicotine or traditional NRT patches,
but the study was too small to make these results statistically
significant.
There are some
non-controlled studies which have reported possible benefit. Electronic cigarettes were not regularly associated with trying to quit tobacco among young people.
A 2014 review concluded that the adverse public health effects
resulting from the widespread use of e-cigarettes could be significant,
in part due to the possibility that they could undermine smoking
cessation. This review therefore called for their use to be limited to smokers who are unwilling or unable to quit.
A 2014 review found four experimental studies and six cohort studies
that indicated that electronic cigarettes reduced the desire to smoke
and withdrawal symptoms. This review also noted that two cohort studies
found that electronic cigarettes led to a reduction in the number of
cigarettes smoked per day.
Harm reduction
Tobacco harm reduction has been a controversial area of tobacco control. The health community have been cautious to support the
tobacco industry to bring safer products to market that will lessen the risks related with tobacco use.
A 2011 review found in the fight to decrease tobacco related death and
disease, e-cigarettes show great promise. A 2014 review found no
long-term evidence on the safety or efficacy of
e-cigarettes, including whether they reduce harm for tobacco related
disease or will improve the health of the population as a whole.
Therefore, promotion of electronic cigarettes as a harm reduction
product is premature. A 2014 review found e-cigarettes may be less
harmful than tobacco cigarettes to users and bystanders.
The same review concluded that health professionals may consider
advising smokers who are reluctant to quit by way of other methods to
switch to e-cigarettes as a safer alternative to smoking
. A 2014 review argued that regulations for electronic cigarettes should
be similar to those for dietary supplements or cosmetic products to not
limit the potential for harm reduction with electronic cigarettes
replacing tobacco.
A 2012 review found electronic systems appear to generally deliver less
nicotine than smoking, raising the question of whether they can
effectively substitute for tobacco smoking over a long-term period.
Smoke from traditional tobacco products has 40 known carcinogens
among the 10,000 chemicals it contains, none of which has been found in
more than trace quantities in the cartridges or mist of e-cigarettes.
[26]
A 2011 review stated that while e-cigarettes can not be considered
"safe" because there is no safe level for carcinogens, they are
doubtless safer compared to tobacco cigarettes.
[26]
Any residual risk of e-cigarette use should be weighed relative to the
risk of continuing or returning to smoking, taking account of the low
success rate of currently-approved smoking cessation medications.
[27] Adults most frequently use electronic cigarettes as a replacement for tobacco, but not always to quit.
[13]
Although some people have a desire to quit smoking by using
e-cigarettes, other common explanations for the use of these products
are to reduce harm from smoking
[28] and to cut back on traditional cigarettes.
[1]
In 2014 a report commissioned by
Public Health England
concluded that there is large potential for health benefits when
switching from tobacco use to other nicotine delivery devices such as
electronic cigarettes, but realizing their full potential requires
regulation and monitoring to minimize possible risks.
[8]
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.
[29] 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 electronic
cigarettes and
smokeless tobacco for long term use instead of smoking.
[30] In an interview, the director of the Office on Smoking and Health for the U.S. federal agency
Centers for Disease Control and Prevention
(CDC) believes that there is enough evidence to say that using
e-cigarettes is likely less harmful than smoking a pack of conventional
cigarettes. However, due to the lack of regulation of the contents of
the numerous different brands of electronic cigarettes and the presence
of nicotine, which is not a benign substance, the CDC has issued
warnings.
[31]
A 2014 WHO report concluded that some smokers will switch completely to
e-cigarettes from traditional tobacco but a "sizeable" number will use
both tobacco cigarettes and electronic cigarettes. 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."
[18]
Safety
The risks of electronic cigarette use are uncertain.
[4][5] This is due to there being little data regarding their
health effects[32]
and to the variability of vaporizers and variability in liquid
ingredients and in their concentration and quality, and thus variability
of the contents of mist delivered to the user.
[1][4][6][31][33] The limited evidence suggests that e-cigarettes are probably safer than traditional
cigarettes.
[6] They are similar in
toxicity to other
nicotine replacement products, but there is not enough data to draw conclusions.
[9] The evidence suggests that the US
Food and Drug Administration (FDA) accepted products such as a
nicotine inhaler may be a safer way to give nicotine.
[7]
A July 2014 WHO report cautioned about potential risks of using
electronic cigarettes. The report concluded that "the existing evidence
shows that ENDS aerosol is not merely "water vapour" as is often claimed
in the marketing for these products. ENDS use poses serious threats to
adolescents and fetuses."
[18] A 2014
systematic review
concluded that the risks of e-cigarettes have been exaggerated by
health authorities and stated that it is apparent that there may be some
remaining risk accompanied with e-cigarette use, though the risk of
e-cigarette use is likely small compared to smoking tobacco.As of 2014, e-cigarettes cannot be regarded as harmless.
A 2013 review found until additional data is available on the topic,
using e-cigarettes cannot be regarded as safe. No long-term studies have
shown that e-cigarettes are a "healthier alternative" to conventional
cigarette
.
Addiction
A number of organizations have concerns that e-cigarettes might
increase addiction to and use of nicotine and tobacco products in the
young. This including: the Centers for Disease Control and Prevention, the
International Union Against Tuberculosis and Lung Disease, the
American Academy of Pediatrics
and the Food and Drug Administration The World Health Organization
raised concern of addiction for nonsmokers from their use in July 2013.
The
National Institute on Drug Abuse
stated that there is a possibility that they could promote continuation
of addiction to nicotine in those who are attempting to quit
.
It
is not clear whether using e-cigarettes will decrease or increase
overall nicotine addiction.The information concerning the drug action of
the nicotine in e-cigarettes is limited.The evidence suggests that the
nicotine in e-cigarettes is adequate to sustain nicotine dependence. The limited data suggests that the likelihood of abuse from e-cigarettes could be smaller compared to traditional cigarettes.
A 2014 systematic review found that e-cigarettes could cause
non-smokers to begin smoking are unsubstantiated. A 2014 review found no
evidence that they are used regularly by those who have never smoked,
while a 2014 review has found that in some populations nearly up to a
third of youth who have ever used electronic cigarettes have never
smoked traditional cigarettes. No long-term studies have been done on
the effectiveness of e-cigarettes in treating tobacco addiction.
The degree to which teens are using e-cigarettes in ways it is not
intended to be used, such as increasing the nicotine delivery, is
unknown
.
The extent to which e-cigarette use will lead to abuse in youth is
unknown. The impact of e-cigarette use by children in respect to
substance dependence is unknown
.
Asal dari Corona Virus
Virus korona manusia ditemukan pada 1960-an.Yang paling awal dipelajari adalah dari pasien manusia dengan flu biasa, yang kemudian dinamai human coronavirus 229E dan human coronavirus OC43. [15] Mereka pertama kali dicitrakan oleh ahli virus Skotlandia Juni Almeida di Rumah Sakit St. Thomas di London. [16] Virus corona manusia lainnya telah diidentifikasi, termasuk SARS-CoV pada 2003, HCoV NL63 pada 2004, HKU1 pada 2005, MERS-CoV pada 2012, dan SARS-CoV-2 pada 2019. Sebagian besar di antaranya melibatkan infeksi saluran pernapasan serius.Infeksi dimulai ketika viral spike (S) glycoprotein menempel pada reseptor sel inang pelengkap. Setelah perlekatan, protease sel inang membelah dan mengaktifkan protein lonjakan yang menempel pada reseptor. Bergantung pada protease sel inang yang tersedia, pembelahan dan aktivasi memungkinkan virus untuk memasuki sel inang dengan endositosis atau fusi langsung dari selubung virus dengan membran inang.
