For the past 15 years the anti-smoking
lobby has pushed the view that cigarette
smoking is a public health hazard. This was a
shrewd tactic. For having failed to persuade
committed smokers to save themselves, finding
proof that passive smoking harmed non-smoking
wives, children or workmates meant smoking
could be criminalized. Last week the science
fell off the campaign wagon when the
definitive study on passive smoking,
sponsored by the World Health Organization,
reported no cancer risk at all.
But don't bet that will change the
crusaders' minds. smoking, like fox hunting,
is something that certain factions want to
ban simply because they don't like it. It has
slipped from a health crusade to a moral one.
Today, National No smoking Day in Britain
will be marked by demagoguery from the
Department of Health, which has already set
its agenda to ban smoking. The U.K.
Scientific Committee on Tobacco or Health
(SCOTH) report on passive smoking, due out
Thursday, is headed by a known anti-tobacco
crusader, Professor Nicholas Wald of the
Royal London School of Medicine.
However, it is now obvious that the health
hazard of environmental tobacco smoke (ETS)
has been knowingly overstated. The only
large-scale definitive study on ETS was
designed in 1988 by a WHO subgroup called the
International Agency on Research on Cancer
(IARC). It compared 650 lung-cancer patients
with 1,542 healthy people in seven European
countries. The results were expressed as
"risk ratios," where the normal
risk for a non-smoker of contracting lung
cancer is set at one. Exposure to tobacco
smoke in the home raised the risk to 1.16 and
to smoke in the workplace to 1.17. This
supposedly represents a 16% or 17% increase.
But the admitted margin of error is so
wide--0.93 to 1.44--that the true risk ratio
could be less than one, making second-hand
smoke a health benefit.
This is what anyone with common sense
might have expected. After all, the dose
makes the poison. But in 1988, IARC decreed
mainstream tobacco smoke as a carcinogen,
fully expecting that the second-hand product
would have a similar, lower effect which
would be capable of measurement by linear
extrapolation. In anticipation of
confirmation of this belief many countries
have been adopting anti-smoking policies in
the name of public health. The U.S.
Environmental Protection Agency has
confidently stated that 3,000 Americans die
annually from inhaling environmental tobacco
smoke, and the state of California leads the
pack with a total smoking ban in all public
places enacted on Jan. 1, 1998. Although Iran
did enact such a ban in 1996, this was
overturned as unconstitutional. The Indian
city of Delhi has a smoking ban and Britain
is working toward one.
Before the IARC study, no other reliable
study on ETS was available. For the effect of
the modestly increased risk of ETS to be
detected, the number of cases in the study
must be very high in order to distinguish the
effect from other background noise. Acting in
the most unscientific manner, the U.S. EPA
decided to pool results of 11 studies, 10 of
which were individually non- significant, to
arrive at a risk ratio of 1.19. As is always
a problem with this kind of meta-analysis,
the studies were all different from each
other in various ways so that they were not
measuring the same thing.
Last October, the British Medical Journal
ran the results of a similarly flawed study
by SCOTH's Mr. Wald claiming an increased
risk of lung cancer from ETS of 26%. It was
supported by an editorial and timed to
coincide with noise from the anti-smoking
lobby and a Department of Health press
release, talking of "shocking"
figures and alluding to innocent victims. The
Wald report has been dismissed as a
"statistical trick" by Robert
Nilsson, a senior toxicologist at the Swedish
National Chemicals Inspectorate and a
professor of toxicology at Stockholm
University. He says that there are so many
unacknowledged biases in Mr. Wald's analysis
that the alleged risk figure is meaningless.
For example, Mr. Wald relies on data from the
memories of spouses as to how much their dead
partner used to smoke. Survey bias is often
considerable, potentially far higher than the
26% estimate of increased risk, but this is
not even mentioned by the authors. Mr.
Nilsson also explains that Mr. Wald's
meta-analysis has pooled data from
non-comparable studies. His most stinging
criticism is aimed at the BMJ editorial
board, who he considers must be
"innocent of epidemiology" to have
allowed publication of the Wald paper in its
existing form. Nevertheless the U.K. SCOTH
inquiry into ETS due to report on Thursday,
with Mr. Wald at the helm, will probably
ignore the flaws of the Wald study and brand
ETS a killer.
New Labour has done a U-turn on fox
hunting. Will it do one on Thursday when
SCOTH reports? Or will it ignore the best
evidence and press on with public smoking
bans? My guess is that two climbdowns in a
month is one too many. It will remind us all
this week that smoking is bad for you and
eventually ban it in public.
Ms. Mooney is medical demographer for
the Cambridge-based European Science and
Environment Forum.
Copyright © 1998 Steven
J. Milloy. All
rights reserved. Site developed and hosted by
WestLake Solutions, Inc.
Source March 2005: http://www.junkscience.com/news/euwsjets.htm
