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Puffing
and inhalation testing
Health New Zealand tests show NZ smokers inhale more
smoke and tar than cigarette packets indicate (based on cigarette company
smoke machine testing)
Health New
Zealand Ltd is the only NZ firm so far equipped to measure puff volumes,
duration of puff, inter-puff interval, total smoke inhalation, and peak
smoke flows
Background The Smoke-free Environments Regulations 1999,
under review in 2005, specify tar and nicotine be tested by the ISO
machine smoking method. Reports from other countries suggested that this
method tended to under report the amount of smoke (and therefore of
nicotine and tar) in comparison with the amount of smoke actually inhaled
by the average smoker.
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Method
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Fig.
1. The Cress Micro transducer
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The portable Cress Micro transducer with mouthpiece and
cigarette holder (Plowshare Technologies USA) enables study of smoking
in natural outdoor non-laboratory settings, without distorting natural
smoking patterns.1
It measures total smoke inhaled per cigarette (total puff volume TPV),
puff volume, average and peak airflow, and inter-puff interval. www.plowshare.com The device (6.5 x 5.5 x 3 cm, battery
operated- see Figure 1) records insertions and removals of a cigarette,
and records volume, interval, and duration of puffs for later uploading
to a computer. It disregards miniscule false puffs, a problem with an
earlier prototype. The puff count for 100 mm cigarettes was scaled to a
standard king size cigarette 83 mm (65 mm rod).
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Subjects Six male smokers smoked 11 cigarettes of their own brand
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Materials Of the 10 manufactured cigarettes, five were 83
mm; and six 100 mm in length.
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Results
Figure
2. Comparison smoke inhaled per cigarette, New Zealand and US smokers, versus smoke
machine.
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Source:
US smokers n=77, smoking cigarettes of 0.9-1.2 mg nicotine
yield. Djordjevic M 2000.2
New Zealand male smokers n=5, smoking 10 cigarettes of 0.5
to 1.1 mg nicotine yield. Laugesen M. using Cress Micro transducer,
2005. Preliminary unpublished data.
The
puff counts
for smoking machine methods are for Marlboro Red regular. Counts ME.
2005.3
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The preliminary Health New Zealand
data agrees well with research from the American Health Foundation New
York.
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The observed total puff volumes per
cigarette correspond closely to the total puff volumes obtained by Health
Canada
intensive method for a regular Marlboro cigarette.
Conclusion
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The Health Canada method is a better guide
to the average smokers’ behaviour than is
the ISO method.
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The ISO test, the test currently used,
greatly underreports cigarette smoke yields.
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The ISO test method underestimates the
exposure to cigarette smoke of those tested by at least half.
Figure
3. Size of smoke puffs: smoking machine test methods versus smokers
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Health New Zealand
preliminary data, using Cress Micro transducer, 2005.
The
average smoker took 47 ml of smoke per puff; whereas a machine
working to ISO specifications, is programmed to
take 35 ml less of smoke per puff.
ISO
method (the lower straight line in Figure 1) underreports the smoke
by 30%. This graph shows that the ISO method corresponds to the lowest
puff volumes recorded among 11 cigarettes smoked.
Health
Canada’s intensive method requires 55 ml puffs to be taken by
the machine every 30 seconds. As Figure 1 shows, this method would be
more in line with the way the mainly young adult males we tested,
actually smoked.
Figure
4. Interval between puffs –
smoking machine versus smokers
- Health New
Zealand preliminary data, using Cress
Micro transducer, 2005.
The average
smoker took a puff every 23 seconds. An ISO-programmed machine will
take a puff every 60 seconds. Add on the average 1.6 seconds for the
duration of the puff itself, and the machine should be taking one puff
every 25 seconds. This underestimates the amount of smoke by 58%.
ISO
method. A smoke machine under
ISO conditions, as NZ cigarette testing regulations have required since
1999, takes a puff every 60 seconds, with an inter-puff interval of 58
seconds.
Health Canada intensive smoking method (puff
every 30 seconds, inter-puff interval 28 seconds) provides a more
realistic way to test cigarettes than the ISO method as currently
required in regulations.
Figure 5. Duration of the puff,
smoking machine versus smokers
Health New Zealand preliminary data, 2005.
The average
smoker took a puff of average duration 1.6 seconds. Smokers’ 3rd
puff was on average deeper (see above), and lasted just over 2 seconds.
All other puffs were shorter than the machine method specified.
Machine
methods. Both methods specify a puff lasting 2 seconds. Whichever
machine smoking method was used, the machine would overestimate duration
of the puff by 20%.
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1
Lee EM, Malson
JL, Waters AJ, Moolchan ET, Pickworth
WB. Smoking topography: reliability and validity in dependent smokers.
Nicotine Tob Res
2003; 5: 673-9.
2
Djordjevic MV, Stellman SD,
Zang E. Doses of nicotine and lung carcinogens
delivered to cigarette smokers. J Nat Cancer Institute 2000; 92: 106-11.
3
Counts ME, Morton MJ, Laffoon
SW, Cox RH, Lipowicz PJ. Smoke composition and
predicting relationships for international commercial cigarettes smoked
with three machine-smoking conditions. Regulatory Toxicology and
Pharmacology 2005; 41: 185-227.
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