DISEASE AND CIVILIZATION
By ALAN MONCRIEFF
THE terms " disease " and " civilization " offer a direct challenge to the scientifically minded, who like to work from clear-cut definitions. Both terms are frankly useful abstractions. Civilization in relation to disease can be regarded. only as it is manifested in its products—the civilized man and woman ; whilst disease is the effect of the interaction between certain injurious agents, varying from bacteria to motor-cars, and the individuals whom they assault. There are, in fact, as Hippocrates taught hundreds of years ago, no diseases, only diseased individuals. The possible effect of civiliza- tion on disease is therefore two-fold, in that it may both vary the nature of the injurious agents and also produce alterations in the resistance and reaction of the individual, There is a further consideration which arises from this. Essentially, the abstractions called " diseases " are little more than labels applied by doctors in the process of making a diagnosis. The better the means available for investigation, the more accurate will such diagnosis be ; and civilization certainly brings with it more effective means of diagnosis and classification.
This is relevant to the often-quoted statement that cancer is a disease of civilization. The fallacies involved in such a generalization, are many. It is obvious that opportunities for the correct certification of causes of death are likely to be better in great modern cities with up-to-date pathological laboratories than in sparsely populated communities in the centre of Africa or the Australian bush. Another factor which adds to the difficulties in estimating the significance of the recent increased incidence of cancer is indicated in the expres- sion " population at risk." During the past fifty years, the expected span of life has considerably lengthened and there are more old people in the community. Cancer is essentially a disorder of the elderly, and is likely to show an increase in its incidence because of the greater propor- tion of potential sufferers. Here is another consideration. The enormous reduction in the infant mortality rate in the past half-century, whereby last year in England and Wales nearly 40,000 more babies survived the first year of life than would have done thirty years ago, possibly means the existence of more relatively weakly individuals, and various consequent increased susceptibilities among adults. The fall in the birth-rate, again, means a relative increase of " first babies." The resulting slightly higher dangers of child-bearing may in part account for the rising death-rate among mothers.
The principal cause of death at all ages today is officially described as " diseases of the heart and circulatory system." These account for more than twice as many deaths as does any other group of disorders.' The effect of civilization on this part of the body's mechanism is considerable. But it must be remembered that modern methods of diagnosis—such as X-rays, the ingenious pulse- recording device of the late Sir James MacKenzie, and the electrical recording of the heart beat—may well mean that the certification of death from heart disease is more accurate than ever before. Consider again the apparent increase in disorders of blood pressure and disease of the arteries. Whether degeneration of the blood vessels precedes changes in blood pressure or whether a rising blood pressure from other causes results in irremediable changes, in the walls of the arteries is still a subject of debate among the experts. They, are agreed, however, that " essential " high-blood pressure, without obvious gross, changes in the arteries, is found more commonly in those who live the type of high-pressure life demanded by the ways in which civilized people earn their livelihoods. Serious changes in the blood vessels which supply nourishment to the heart muscle also appear to be more common than ever before. The strain of modern life may well be a factor in their causation.
Then again, as already mentioned, the type of injurious agent may be varied by eiVilization. The part played by the motor-car in the death-returns needs no emphasis here. Modern bacteriological science shows that certain microbes, especially the group known as streptococci, are playing an increasingly important part as disease pro- ducers. The national problem of the rheumatic disorders is probably closely concerned with this group of organ- isms as one of the important factors. Modern sleeping arrangements in public schools and institutions appear to offer facilities for the streptococcus to paSs from one boy or girl to another. The problems of ventilation and the heating of houses do not arise for the out-of-door uncivilized individual ; but the indoor canditicins in which civilized man is forced to spend such a very large proportion of his life Call for adjustments and adaptations which man has not yet succeeded in accomplishing.
But even the out-door environment of the city worker is little less inimical to Man's normality. - The pollution of the atmosphere by smoke exposes the delicate lining membranes of the lungs to irritation, 'against which resis- tance can be but slowly built up. An apparent increase in cancer of the lung in recent times is sometimes attri- buted in part to this cause. The acid fumes in London are powerful enough to eat into the stone-work of the Houses of Parliament—a natural propagandist hint, if there ever was one.
Tuberculosis, one of the scourges of the civilized areas of the world, appears, in certain countries, in- c!uding our own, to be yielding to scientific attack. The factors which led to its prevalence are appar- ently being brought under control. One group of the population, however, does not share in the general decrease in the tuberculosis mortality rate, the group which includes the young adolescent girl. The in- creased employment of women in industry has, without doubt, raised many new problems for the health authori- ties. The average young female office-worker lives a thoroughly unhygienic life, civilization offering her easy transport in crowded vehicles, late nights spent in the cinema or dance-hall, and facilities for eating the wrong sort of machine-prepared food in insufficient quantity amid attractive surroundings. To such injurious agents, her reactive capacity, amazingly good in some instances, is bound to be weakened sooner or later. Not surpris- ingly, tuberculosis takes its toll. Among the survivors, and perhaps more among the working women of the north, anaemia is a severe handicap to health.
Civilization has increased the hygienic risks of mankind in many directions, without coincidently bringing the means of countering them. The decreased risk to life from ancient causes, consequent on the success of our public health " methods, means that more people survive to old age and are exposed to the dangers peculiar to senescence. Meanwhile, in my opinion, the general quality of the race as regards health is certainly on the up-grade; but the problem is a complex one.