Yahoo – AFP,
22 Jan 2015
A man smokes an electronic cigarette on February 20, 2014 in Miami, Florida (AFP Photo/Joe Raedle) |
Miami (AFP)
- When heated to the max and inhaled deeply, e-cigarettes produce the toxic
chemical formaldehyde, which could make the devices up to 15 times more
cancerous than regular cigarettes, US researchers said Wednesday.
E-cigarettes
are battery powered devices that heat up a liquid containing nicotine and
artificial flavoring. The vapor is inhaled, much like a cigarette.
While some
say e-cigarettes may help tobacco smokers kick the habit, others are concerned
that the unregulated devices are being marketed widely despite little long-term
evidence about their health effects.
The team
from Portland State University experimented with a machine that
"inhaled" e-cigarette vapor at low voltage and high voltage to see if
and how much formaldehyde was produced by the heating of the vaping liquid,
which contains flavoring chemicals, nicotine, propylene glycol and glycerol.
The machine
took 10 puffs over the course of five minutes, each puff lasting three to four
seconds.
No
formaldehyde was detected when the machine operated at the low, 3.3 voltage
setting, the authors said in a research letter published by the New England
journal of Medicine.
But when it
inhaled at the highest setting, five volts, formaldehyde was detected, at
levels far higher than seen in conventional tobacco cigarettes.
At high
voltage, an e-cigarette user vaping at a rate of three milliliters per day
would inhale about 14 milligrams of formaldehyde per day in
formaldehyde-releasing agents, the article said, describing the estimate as
"conservative because we did not collect all of the aerosolized liquid,
nor did we collect any gas-phase formaldehyde."
The daily
estimate of formaldehyde exposure for a pack-a-day smoker is three milligrams.
That level
of exposure could boost the risk of cancer five to 15 times higher than in
long-term smokers, it added, using two previous studies on formaldehyde in
cigarettes as reference.
"How
formaldehyde-releasing agents behave in the respiratory tract is unknown, but
formaldehyde is an International Agency for Research on Cancer group 1
carcinogen," the article said.
"Formaldehyde-releasing
agents may deposit more efficiently in the respiratory tract than gaseous
formaldehyde, and so they could carry a higher slope factor for cancer."
Peter
Hajek, director of the Tobacco Dependence Research Unit at Barts and The London
School of Medicine and Dentistry, said the study did not reflect real-world
conditions.
"In
e-cigarette use by humans, overheating the liquid generates acrid tasting 'dry
puff' which is unpleasant and avoided rather than slowly inhaled," said
Hajek, who was not involved in the study.
"When
a chicken is burned, the resulting black crisp will contain carcinogens but
that does not mean that chicken are carcinogenic," he added.
"Vaping
may not be as safe as breathing clear mountain air, but it is much safer than
smoking. It would be a shame if this study persuaded smokers who cannot or do
not want to stop smoking and contemplate vaping that they might as well stick
to their deadly cigarettes."
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