ON CONTRASTING MARIJUANA WITH TOBACCO AND ALCOHOL

The recent "flap" about our comparative report on the health risks of
marijuana (Marijuana Flap Gets Pot Boiling at WHO -- March 3) is more
interesting for what is left unsaid in the media than for what happened
about its publication.

Three of us -- one researcher in Australia, two in Canada -- were asked by
an Expert Working Group of the World Health Organization (WHO) to prepare a
report comparing the health and psychological consequences of marijuana,
alcohol, tobacco and opiates, on the basis of existing research. This was
one of 16 commissioned review papers in WHO's first review of marijuana and
health since 1982. By arrangement with WHO, the whole series of papers,
updated by their authors, will be published later this year as an Addiction
Research Foundation book by the Addicition and Mental Health Services
Corporation of Toronto.

Drawing on papers, WHO published a summary report late last year. The flap
has been about this report, since it dropped the comparisons wih other
drugs, arguing "the reliability and public health significance of such
comparisons are doubtful." However, the report acknowledged the existence
of our comparison paper, and WHO staff have sent copies of it on request.
It would therefore not be accurate to say our paper has been suppressed.

What about the claim that comparisons are unreliable or unscientific? This
is very much a matter of judgement. Everyone would agree that more
research, particularly on the epidemiology of harms from marijuana, is
needed. But in my view enough is known for such comparisons to be useful.
Indeed, both the public and the public policy process deserve from
scientists our best efforts and advice on important issues of public health
and policy.

Two big things are left unsaid in the flap. One is that marijuana does
cause harm to health. Our paper has a long catalogue of these harms. In the
debates over marijuana's legal status, these harms should not be denied.

The second is that marijuana appears relatively less harmful only because
of the severe and wide-ranging health and social harms from alcohol and
from tobacco. Even gross comparisons are illuminating on this. The
accompanying table lists the main adverse health effects of the three
drugs, with a rough distinction between effects that are important in terms
of numbers affected and effects that are less well-established or less
important numerically. In some respects, the table is a matter of
judgement. And it does not consider potential beneficial effects of each
drug. But it makes that point thjat there are important harms from both
alcohol and tobacco that do not exist for marijuana.

Comparing Adverse Effects on Health

xx Important effect x Some effect known or suspected

Marijuana Alcohol Tobacco

Traffic and x x other accidents

Violence xx and suicide

Overdose x Death

Liver cirrhosis x

Heart disease x xx

Respiratory x xx
diseases

Cancers x x xx

Mental illness x x

Addiction xx xx xx

Lasting effects x xx x on
fetus

In a society like ours, where commerce in alcohol and tobacco is deeply
entrenched, where leading sports and cultural institutions depend on
alcohol or tobacco sponsorship, and where media draw considerable revenue
from alcohol and tobacco advertisements, we tend to look away from the
health and social harms of alcohol and tobacco.

Our worries about illicit drugs sometimes seems like a convenient
distraction. But it is alcohol and tobacco that are the main sources of
drug harm in Canada today, as the cost-of-illness comparisons of the
Canadian Center on Substance Abuse showed: $7.5-billion in 1992 for
alcohol, $9.5-billion for tobacco, and $1.4-billion for all illicit drugs
together.