We all agree, I am sure, that excess in and abuse of any human activity are undesirable and should be discouraged whether it is the use of alcohol or coffee or tobacco or the function of eating, of exercise or inactivity, of work or recreation. For the vast majority, however, the temperate expression of most of these same activities is an essential part of total health and well-being.
When any of these commonplace activities falls under suspicion as being a specific factor in the causation of human disease, we can agree also that this is a matter for serious consideration, but we must be extremely cautious in evaluating the basis for such suspicion and the extent of the supposed risk involved, and in avoiding the creation of fear and panic.
This is especially true today, when we are dealing with ailments, such as cancer and heart disease, of people mostly in advanced age groups. These do not, so far as our present knowledge goes, fit into the categories of the old-time pathologists—they are not specific diseases produced by specific causes with specific patterns of injury to specific tissues.
It is now generally agreed that they are, at least in part, diseases related in some way to present-day stress, modern environment, and to extension of life into the problem of old age. The worries of home, of business, of driving along highways of crowded living, the search for relaxation and, not the least, the fears of being sick or of catastrophe have an untold effect upon the body and, if sufficiently intense, may certainly lead to illness, if not cause it.
As to seeking specific causes of cancer, and also heart disease, science is only now on the threshold of what I hope will be great advances in developing better methods of testing the biologic activity of many, many substances that we all use or are exposed to from day to day and, more important, of assigning to them their relative place in the scale of risks we assume in our daily lives. For it cannot be gainsaid that while there is an absoluteness about the hazards to life, there is no such thing as absolute safety for life. The very things that are essential or important to continued, effective living may be harmful or even fatal under conditions of misuse or abuse.
In the field of tobacco use and health, all concerned admit the need for more knowledge and research. Differences exist mainly over the evaluation of our present knowledge or lack of it, and the direction and emphasis of future research.
There are some who feel and proclaim that "beyond reasonable doubt" cigarette smoke contains one or more as yet unknown substances that may cause cancer in man. They would concentrate their research on isolating, identifying, or removing these substances even though no such agent has been discovered experimentally.
Others believe, however, that the existence in tobacco smoke of substances carcinogenic to the lungs of men has not been and cannot be proved by statistical associations or by painting the skin of mice of certain specific strains with highly concentrated extracts of tobacco smoke. They therefore focus attention on development of more exact and more direct methods of assaying the cancer-inducing powers of suspected substances. In this direction may be found contributions not only to the smoking question but also to the total problem of bio-assay of other substances.
FEAR OR CALM DELIBERATION?
Generally speaking, the public believes in dicta from scientists or public health groups. Doubt, suspicion, fear, and mental tension can be created and maintained by one type of presentation of a situation. Balance, poise, a judicial attitude and calm deliberation can be engendered by another. For at least four years there have been repeated, sensational, and fear-arousing statements and resultant headlines on the theoretical lethal nature of tobacco smoke.
The repeated expression of these views, however, is no measure of their general acceptance by all who are concerned with the problems involved. For instance, the statistical evidence in support of the cigarette theory has not been accepted as proof of generalized conclusions about smoking by a number of distinguished statisticians, among whom may be mentioned especially Dr. Joseph Berkson, Section of Biometry and Medical Statistics of the Mayo Foundation for Medical Education and Research in Rochester, Minnesota.
There are certain unfeatured but fundamental contradictions in different statistical papers from which points of agreement have been selected for presentation by advocates of the "cigarette guilt" theory.
For example, the implication of the American school of cigarette theorists is that inhalation and, therefore, direct contact of smoke with lung tissue is an important factor in the origin of lung cancer. On the other hand, certain British investigators state that it would appear that inhalation is a "negligible" factor. If this is the case, direct contact is not an important element. In any attempt to identify a suspected agent or agents, these two possibilities are an unsolved complication and are evidence of incomplete knowledge.
The clinical pathological data of one American Cancer Society grantee was hailed by the then medical director of that society as "the very evidence skeptics demanded." These same data have not been so evaluated by a considerable number of trained clinical pathologists not affiliated with the American Cancer Society but familiar with much more data of a similar nature.
The reports of inducing skin cancer on some mice by smearing highly concentrated tobacco smoke condensates have been countered not only by similar experiments failing to result in cancer but by universally negative carcinogenic results reported by a number of investigators following the inhalation of cigarette smoke or its injection directly into the lungs of rodents.