For those who are familiar with the May 17, 2003 BMJ paper on passive
smoking by Enstrom and Kabat
(http://bmj.com/cgi/reprint/326/7398/1057.pdf) and the resulting
controversy described in more than 150 rapid responses
(http://bmj.com/cgi/eletters/326/7398/1057), I want to bring an important
development to your attention. On February 14, 2006 Professor Sir Richard
Peto of the University of Oxford testified before The Select Committee on
Economic Affairs of the House of Lords in London regarding the health
risks of passive smoking and the proof copy of the minutes of evidence are
now available, as explained on the first page of the transcript
(http://www.publications.parliament.uk/pa/ld/lduncorr/econ140206.pdf).
Questions Q381-Q404 on this subject and his complete responses can be
found on pages 16-28 of the uncorrected and unpublished transcript of
evidence taken in public. Selected quotes are shown below.
Part of Q381 was “Sir Richard, I want to start by asking if you could
give us your assessment of the health risks associated with passive
smoking . . .” Part of his response was “I am sorry, I know that is what
you would like to be given, but the point is that these risks are small
and difficult to measure directly. What is clear is that cigarette smoke
itself is far and away the most important cause of human cancer in the
world – that is, cigarette smoke taken in by the smoker – and passive
smoking, exposure to other people’s smoke, must cause some risk of death
from the same diseases.”
Part of his response to Q389 was “The trouble is that because these
risks are small they are difficult to measure, for obvious reasons, and
the studies that have been done on heart disease – in many populations the
main way cigarette smoke kills smokers is by causing death from heart
disease rather than causing death from lung cancer, it varies from one
population to another. . . . (O)n heart disease . . . these studies
indicate risks that are a lot bigger than would be expected from
extrapolation. Nobody has really argued the studies away, yet everybody
feels uncomfortable with the conclusion unless it can be better
understood.”
Part of his response to Q400 was “Yes, certainly, as you know, you
are going to get people who are enthusiastic about tobacco control wanting
to have studies demonstrating the hazards of passive smoking and, as a
result, you will get some claims that are not justified.”
Q401 was “Could I draw you out on one further thing. You have been
unwilling to quantify the risks from passive smoking.” His answer was
“Yes.”
Sir Richard’s testimony is not inconsistent with the conclusions of
the Enstrom and Kabat paper, which are: “The results do not support a
causal relation between environmental tobacco smoke and tobacco related
mortality, although they do not rule out a small effect. The association
between exposure to environmental tobacco smoke and coronary heart disease
and lung cancer many be considerably weaker than generally believed.”
Because of this testimony, please recall the criticism of the Enstrom
and Kabat paper by the International Agency for Research on Cancer (IARC)
Working Group which authored the 1452-page May 2004 IARC Monographs Volume
83, “Tobacco Smoke and Involuntary Smoking,”
(http://monographs.iarc.fr/ENG/Monographs/vol83/volume83.pdf). This
criticism was contained in their May 30, 2003 bmj.com rapid response
(http://bmj.bmjjournals.com/cgi/eletters/326/7398/1057#32784) and their
subsequent August 30, 2003 BMJ letter
(http://bmj.com/cgi/content/full/327/7413/501-b), which ended with the
following sentence: “Enstrom and Kabat’s conclusions are not supported by
the weak evidence they offer, and, although the accompanying editorial
alluded to 'debate' and 'controversy,' we judge the issue to be resolved
scientifically, even though the 'debate' is cynically continued by the
tobacco industry.” It is important to note that only 14 of the 25 Working
Group members were listed as supporting this criticism. Although five
senior US epidemiologists (Drs. Patricia Buffler, Elizabeth Fontham,
Jonathan Samet, Michael Thun, and Anna Wu) were among the 14 members
listed, Sir Richard was among the 11 members who were not listed. The
names of all 25 members can be found on pages 3 and 4 of Volume 83.
Sir Richard’s testimony is direct evidence that there is substantial
doubt in the mind of a preeminent epidemiologist about the quantitative
health risks of passive smoking. Hopefully, this fact will help
contribute to rational and objective evaluation of the health risks of
passive smoking. Hopefully, this evaluation can be based on the
epidemiologic findings themselves, where their merits can be properly
assessed without being influenced by ad hominem attacks.
Competing interests:
The same as those stated previously.
Rapid Response:
Professor Sir Richard Peto and the House of Lords
For those who are familiar with the May 17, 2003 BMJ paper on passive
smoking by Enstrom and Kabat
(http://bmj.com/cgi/reprint/326/7398/1057.pdf) and the resulting
controversy described in more than 150 rapid responses
(http://bmj.com/cgi/eletters/326/7398/1057), I want to bring an important
development to your attention. On February 14, 2006 Professor Sir Richard
Peto of the University of Oxford testified before The Select Committee on
Economic Affairs of the House of Lords in London regarding the health
risks of passive smoking and the proof copy of the minutes of evidence are
now available, as explained on the first page of the transcript
(http://www.publications.parliament.uk/pa/ld/lduncorr/econ140206.pdf).
Questions Q381-Q404 on this subject and his complete responses can be
found on pages 16-28 of the uncorrected and unpublished transcript of
evidence taken in public. Selected quotes are shown below.
Part of Q381 was “Sir Richard, I want to start by asking if you could
give us your assessment of the health risks associated with passive
smoking . . .” Part of his response was “I am sorry, I know that is what
you would like to be given, but the point is that these risks are small
and difficult to measure directly. What is clear is that cigarette smoke
itself is far and away the most important cause of human cancer in the
world – that is, cigarette smoke taken in by the smoker – and passive
smoking, exposure to other people’s smoke, must cause some risk of death
from the same diseases.”
Part of his response to Q389 was “The trouble is that because these
risks are small they are difficult to measure, for obvious reasons, and
the studies that have been done on heart disease – in many populations the
main way cigarette smoke kills smokers is by causing death from heart
disease rather than causing death from lung cancer, it varies from one
population to another. . . . (O)n heart disease . . . these studies
indicate risks that are a lot bigger than would be expected from
extrapolation. Nobody has really argued the studies away, yet everybody
feels uncomfortable with the conclusion unless it can be better
understood.”
Part of his response to Q400 was “Yes, certainly, as you know, you
are going to get people who are enthusiastic about tobacco control wanting
to have studies demonstrating the hazards of passive smoking and, as a
result, you will get some claims that are not justified.”
Q401 was “Could I draw you out on one further thing. You have been
unwilling to quantify the risks from passive smoking.” His answer was
“Yes.”
Sir Richard’s testimony is not inconsistent with the conclusions of
the Enstrom and Kabat paper, which are: “The results do not support a
causal relation between environmental tobacco smoke and tobacco related
mortality, although they do not rule out a small effect. The association
between exposure to environmental tobacco smoke and coronary heart disease
and lung cancer many be considerably weaker than generally believed.”
Because of this testimony, please recall the criticism of the Enstrom
and Kabat paper by the International Agency for Research on Cancer (IARC)
Working Group which authored the 1452-page May 2004 IARC Monographs Volume
83, “Tobacco Smoke and Involuntary Smoking,”
(http://monographs.iarc.fr/ENG/Monographs/vol83/volume83.pdf). This
criticism was contained in their May 30, 2003 bmj.com rapid response
(http://bmj.bmjjournals.com/cgi/eletters/326/7398/1057#32784) and their
subsequent August 30, 2003 BMJ letter
(http://bmj.com/cgi/content/full/327/7413/501-b), which ended with the
following sentence: “Enstrom and Kabat’s conclusions are not supported by
the weak evidence they offer, and, although the accompanying editorial
alluded to 'debate' and 'controversy,' we judge the issue to be resolved
scientifically, even though the 'debate' is cynically continued by the
tobacco industry.” It is important to note that only 14 of the 25 Working
Group members were listed as supporting this criticism. Although five
senior US epidemiologists (Drs. Patricia Buffler, Elizabeth Fontham,
Jonathan Samet, Michael Thun, and Anna Wu) were among the 14 members
listed, Sir Richard was among the 11 members who were not listed. The
names of all 25 members can be found on pages 3 and 4 of Volume 83.
Sir Richard’s testimony is direct evidence that there is substantial
doubt in the mind of a preeminent epidemiologist about the quantitative
health risks of passive smoking. Hopefully, this fact will help
contribute to rational and objective evaluation of the health risks of
passive smoking. Hopefully, this evaluation can be based on the
epidemiologic findings themselves, where their merits can be properly
assessed without being influenced by ad hominem attacks.
Competing interests:
The same as those stated previously.
Competing interests: No competing interests