CHAPTER THREE: URBAN LIFE AND HEALTH
The Changing Urban Scene
Man’s environment attains a high degree of simplification in the modern metropolis. At first this may seem surprising: We normally associate metropolitan life with a diversity of individual types and with variety and subtlety in human relations. But diversity among men and complexity in human relations are social and cultural phenomena. From a biological point of view, the drab, severe metropolitan world of mortar, steel, and machines constitutes a relatively simple environment, and the sharp division of labor developed by the modern urban economy imposes extremely limited, monotonous occupational activities on many of the individuals who make their livelihood in a large city.
These have not always been the characteristics of urban life. The metropolitan milieu represents a sharp departure from the forms and styles of life that prevailed in communities of the pre-industrial era. Early towns produced highly varied and colorful environments. Students of the medieval commune and the Renaissance city never fail to single out the humanizing artistic touch that the urban dweller gave to his home and to everyday articles. Craftsmen seldom permitted the function of an object to completely dominate its form. Decorativeness is to be found even in tools and weapons-objects which in our day are noteworthy for their purely functional design. This high sense of individual artistry was nourished by a vocational tradition that directed the workman to nearly every phase of the making of a product. The craftsman often prepared his raw material with his own hands, smelting his metals or tanning his leather. The great architects and engineers of the Renaissance not only designed a structure but also participated in its construction. The roundedness of the Renaissance man, which we look upon with so much envy today, was due in large part to a unity of mind and body, to a combination of thought and physical activity.
Early urban life was leisurely and relaxed. Craftsmen worked more or less in accordance with a pace established by physiological cycles, accelerating the tempo of their work during moments of energy and slowing down or halting entirely during periods of lethargy. The rate of physical activity was determined by the body’s vitality rather than by external agencies, such as machines. Men did not try to “conserve” their energy and distribute it uniformly, as though it were an inorganic resource; human energy is seldom “conserved,” in this simple, mechanical sense. Craftsman and artist worked by “fits and starts,” giving themselves over to a task to the degree that their bodies were amenable to physical activity and artistic endeavor. Labor and art were seldom forced. The tempo of work varied, from hour to hour and day to day,with the changing vitality of the body.
The town developed in an agricultural matrix. Farms lay directly outside the city, not in a far-removed perimeter that the traveler could reach only after a long journey through suburbs and “exurbs.” A short stroll carried the urban dweller from the market place, on which the principal cultural activities of the community were centered, into open fields and orchards. Farmer and city man intermingled freely. In many cases, the urban dweller combined the work of a craftsman with that of a food grower, often maintaining a small garden inside the city walls to supply some of his own food. “One must not look at the narrow streets between the houses without remembering the open green, or the neatly chequered gardens, that usually stretched behind,” observes Lewis Mumford.
Food staples were grown nearby, on farms that produced a variety of crops. As soon as a crop was harvested, it found its way quickly to the market place and from there to the urban consumer. The city dweller was never completely urbanized, in the narrow sense, as he is today. Gardening within the city and easy access to the countryside helped to fuse all aspects of urban and country life.
Early city life, to be sure, was burdened with many problems that have largely been solved by modern science and technology. Diet was severely restricted, especially in medieval times, and fresh foods were available only during the growing season. Sanitation remained primitive for centuries, although Mumford points out that the existence of open spaces in the medieval town “shows that sanitary arrangements were not necessarily as offensive as they have been pictured, nor vile smells as uniformly ubiquitous.” Agricultural techniques were crude and few advances were made in transportation until railroads came into existence, but the early towns put the tools and the knowledge at their disposal to the best possible use. Life was usually serene. “One awoke in the medieval town to the crowing of the *censored*, the chirping of birds nesting under the eaves, or to the tolling of the hours in the monastery on the outskirts, perhaps to the chime of bells in the new belltower. Song rose easily on the lips, from the plain chant of the monks to the refrains of the ballad singer in the market place, or that of the apprentice and the house-maid at work. As late as the seventeenth century, the ability to hold a part in a domestic choral song was rated by Pepys as an indispensable quality in a new maid. There were work songs, distinct for each craft, often composed to the rhythmic tapping or hammering of the craftsman himself. Fitz Stephens reported in the twelfth century that the sound of the water mill was a pleasant one amid the green fields of London. At night there would be complete silence’ but for the stirring of animals and the calling of the hours by the town watch. Deep sleep was possible in the medieval towns, untainted by either human or mechanical noises.”
Modern science has eliminated nearly all the difficulties that earlier urban communities faced. Owing to advanced means of transportation, the city dweller now enjoys a highly varied diet, and the metropolis receives abundant supplies of foods of all types the year round. Sanitation has reached a high technical level; the daily wastes of millions of people are removed without hazard to public health. And yet for every difficulty science has eliminated, the metropolis has created a new and greater problem in our manner of urban life.
The metropolis lacks nearly all the humanizing features of early urban life. In the medieval and Renaissance towns, intellectual activity and art were combined with physical labor; in the metropolis, intellectual activity, art, and physical labor are sharply separated. The civil engineer who designs a structure seldom participates in its construction; his counterpart in the field rarely engages in design. Architects like Frank Lloyd Wright, who concerned himself with nearly every phase of construction, are rarities. Most jobs in the metropolis are sedentary and monotonous. Some of the more rapidly growing occupations require very little mental or physical work; they are mindless as well as sedentary. Work of this kind is typified by the tasks of the billing-machine operator and the dictaphone pool typist, whose principal qualification is the ability to endure an excruciatingly vacuous routine.
The current occupational trend is toward an extreme simplification of the labor process. Work is fragmented, limited, and overspecialized. Modern industry has broken down many highly skilled crafts into repetitive tasks that the worker can perform mechanically, by habit, without losing time either in thinking or in changing tools. Work tends to become sedentary, not because the comfort of the worker is kept in mind, but because any unnecessary movement of the body tends to diminish output by interrupting the smooth, uniform flow of labor. The same trend is evident in intellectual and artistic work, where over-specialization tends to replace creative activity with mechanical operations. While many such jobs allow for considerable individual leeway, progressively fewer faculties are used or developed. In the worst cases, physical work is limited to a few dexterous operations of the fingers, mental work to a few dexterous operations of the mind.
Labor becomes highly intensive. The few faculties that are brought into play are employed at continually higher rates of speed. Work is viewed more as a function of habit than as the function of individual resources and talents whose use requires patience and tolerance. Thus, many jobs not only tend to restrict the use of certain parts of the body, but employ other parts excessively. Forms of work which once mobilized the human organism as a whole are supplanted by occupations that tax the eyes or the nerves. While the mind is dulled and the human musculature becomes flaccid, nerves become overly sensitive and raw. The anxieties and tensions created by intensive, sedentary work are reinforced by an exaggerated responsiveness of the nervous system as a whole.
The metropolis offers very little to counteract the oversimplification of the daily work routine. The urban dweller encounters few changes in color to awaken his visual senses; he receives virtually no respite from the artificial world in which he is immersed during working hours. Areas in which he can walk freely on soil and amid vegetation are disappearing; new dwellings, most of them noteworthy for their lack of architectural inspiration, are encroaching on the last open spaces in American cities. Public parks are likely to be congested during the day, and in the evening they often attract delinquent elements, whose presence discourages the respectable urban dweller from venturing into their precincts. American urban life has retreated indoors. This retreat is due partly to the erosion of human solidarity in large cities, partly to the seductive powers of the mass media. The average urban dweller is likely to pursue the same insensate, sedentary way of life during his leisure time that he follows during his working hours.
Many aspects of metropolitan life, while trivial in themselves, aggravate the effects of urban modes of work. The nervous strain that the city dweller feels at his job begins to gather within him even before he gets to work. He encounters inconveniences, rudeness, and congestion on public conveyances; he is beleaguered by countless small anxieties, many of which seldom rise to the level of consciousness. An all-pervasive irritation collects within him on his way to work, at work, between working hours, and on the way home. Mechanical noises are everywhere. They invade even the hours of sleep as a result of the growing web of highways that reaches into every part of the city. Advertising media assail the senses with garish images and sounds; their message is crude and elemental, designed to startle and perhaps to shock the viewer into a response. Recreation seldom furnishes the average urban dweller with the experiences denied to him in the daily bustle of life-moments of genuine serenity, silence, and gentle changes of scene. More often than not, urban recreation merely removes him temporarily from the afflictions of his environment without replenishing his reserves. It provides him with surcease from anxiety and nervous strain rather than with restoration of vitality.
Unfortunately, these problems are no longer confined to the city. The metropolis establishes the social standards of the entire country. Owing to its commanding economic and cultural position, it sets the pace of national life and establishes nearly all the criteria of national taste. Many distinctively urban forms of work and play have invaded the most remote rural areas of the United States, where they generate the same stresses in the villager and farmer that they do in the city dweller. The nature of agricultural work, moreover, is changing. As farming becomes increasingly industrialized, diversified physical work is reduced to a minimum by machines and one-crop agriculture. Although the farmer still pursues a less hurried way of life than his urban cousin, he is often beleaguered by even greater economic problems. Both in the city and on the land, a new type of man seems to be emerging. He is a nervous, excitable, and highly strained individual who is burdened by continual personal anxieties and mounting social insecurity.
Stress and Chronic Illness
What are the effects of persistent emotional stress on human health?
Fifty years ago this question would have seemed irrelevant to the goals of medical research. The principal illnesses of the day were ascribed to the aging process, to a variety of “mechanical defects,” such as blockages and ruptures, to a poor genetic endowment, and to bacterial infection. Germs satisfied the need for precise explanations of disease. They entered the body in a limited number of ways; they could be isolated, cultured, and tested on animals and human volunteers. With further knowledge, it was believed, all the effects produced by harmful bacteria would be understood and eventually controlled by some form of therapy. Emotional stress, on the other hand, was vague. It seemed to represent a generalized response on the part of the body to countless, often intangible stimuli. Although medicine was not unaware of the fact that emotional disturbances influenced the functioning of the heart and gastrointestinal tract, there seemed little reason to believe that stress played a causal role in the major diseases of man. (To cite a few exceptions: As early as the 1870’S Dr. Jacob Mendes Da Costa described a syndrome which has since acquired the name of cardiac neurosis. Certain digestive disturbances were also recognized as being influenced by the emotional state of a patient, but these were often minor in nature.)
As chronic illnesses began to gain in importance, however, it became evident that the earlier approach was inadequate. Many arthritic conditions, for example, could not be explained by infection. Beginning slowly and insidiously, arthritis often produced in the end a hopelessly crippled, bedridden patient who faced a lifetime of pain and inactivity. At the same time, such words as “strain” and “anxiety” began to acquire real physiological meaning, denoting conditions that involved glandular conditions, biochemical changes in tissues, and involuntary activity of the nervous system. It was soon found that these physiological changes could produce or alleviate many of the symptoms associated with the common chronic diseases of our time.
A growing number of physicians now agree that emotional stress is a very important disease-promoting factor. It is safe to say that some disorders, such as peptic ulcers, arise primarily from anxiety and tension. During the latter part of the nineteenth century, peptic ulcers were regarded as a relatively uncommon disorder, and there arose very confused explanations of what caused the illness. Physicians generally believed that it occurred more frequently in women than in men, it was looked upon as a disorder primarily of “chlorotic,” or anemic, girls. In the medical textbooks of the day, discussions of peptic ulcers were confined to descriptions of symptoms and dietary therapy. With the passing years, however, the disease became a widespread and serious problem. Today, peptic ulcers afflict about ‘1/a million Americans; each year nearly 4oo,ooo are disabled for more than a week. Although a case of ulcers may often arouse a great deal of levity, the disease can reach grave proportions. About ten thousand Americans die of peptic ulcers every year. According to data compiled by the U. S. National Health Survey of 1957-9, the overwhelming majority of ulcer victims (73 per cent) are men. | More cases appear in the thirty-five-to-forty-four age group-the years of greatest business and vocational activity-than in any other ten-year period of life.
Emotional stress is also deeply implicated in disorders of the blood vessels and the heart. “Physicians have long felt that the rapid pace of modern civilization might somehow be contributing to the development of heart disease,” notes a report by the National Heart Institute. “The man who develops coronary artery disease is very frequently a hard-driving individual living in a state of more or less constant tension. In recent years evidence has accumulated that one way in which nervous tension may accelerate the development of coronary artery disease is through an elevation of the [blood] serum cholesterol level.”
The evidence is impressive. In I 957, Friedman, Rosenman, and Carroll, of Mount Zion Hospital in San Francisco, began a study of the serum cholesterol level and blood-clotting time in forty male accountants during and after the tax season-sharply contrasting periods of high and low occupational stress. Blood was taken from the accountants twice weekly from January to June, and detailed records were kept of weight, diet, and changing work loads. “”When studied individually,” the investigators report, “each subject’s highest serum cholesterol consistently occurred during severe occupational or other stress, and his lowest at times of minimal stress. The results could not be ascribed to any changes of weight, exercise, or diet. Marked acceleration of blood clotting time consistently occurred at the time of maximum occupational stress, in contrast to normal blood clotting during periods of respite.”
Studies of a similar nature have been made of medical students during examination week. In 1958 a report of P. T. Wertlake at the College of Medical Evangelists in Los Angeles showed that the average serum cholesterol level of the students rose 11 percent during the four-day period in which they took school tests. The investigators found that nearly half of the students responded to the stress situation with increases ranging from 16 to 137 milligram per cent over a mean control level of 213. The serum cholesterol level of one student rose from an average control level of 259 milligram percent prior to the school examinations to a peak of 536 during one of the examination days-an increase of more than 100 percent. It would be wrong to suppose, however, that our knowledge of the link between emotional stress and illness is based entirely on statistical findings. During the past two decades, researchers have discovered a number of the biochemical effects that persistent anxiety produces in the human body. Attention has focused primarily on the adrenal glands, which cap the kidneys. The surface layer, or cortex, of these glands produces a number of highly potent regulatory chemical substances, or hormones. The cortical hormones, or corticoids, help the body to ward off disease and resist the effects of physical damage. A number of adrenal corticoids (aldosterone and DOC, for example ) promote inflammation-the heat, swelling, and redness with which tissues react to common injuries. Although inflammation protects the body from bacterial invasion by “walling off” an injured area, the inflammatory process would go too far if it were not for anti-inflammatory corticoids, such as cortisone, which limit the process and prevent it from becoming needlessly widespread. The output of cortisone, in turn, is stimulated by ACTH, a hormone produced by the pituitary gland, situated at the base of the skull. The control of the pro-inflammatory corticoids, and of the anti-inflammatory corticoids. If the balance in the secretion of these three types of hormones is altered, the inflammatory process may damage parts of the body.
Secretions of ACTH and the corticoids are influenced by the emotional state of the individual as well as by physical injury. This discovery has aroused strong suspicions that the corticoids and, by inference, persistent nervous strain, anxiety, and emotional conflicts play important roles in the occurrence of certain chronic disorders. In a review of the literature on rheumatoid arthritis and stress, Leon Hellman has suggested that “a more subtle form of stress in the guise of emotional conflicts is implicated in changes of the pituitary-adrenal system so as to render it less responsive or to alter the balance between various adrenal hormones secreted. A patient with rheumatoid arthritis would cure himself if his hypothalamus [a nerve center in the forebrain] and pituitary would interlock to increase the secretion of ACTH . . .” According to Hellman, it is quite possible that the production of ACTH is inhibited by a “neural block” arising from deep-seated emotional conflicts. Both ACTH and cortisone have been used with considerable success in treating arthritic disorders. The hormones alleviate rheumatoid symptoms so dramatically that hopelessly crippled, bedridden arthritics have been restored to almost complete use of their limbs.
The adrenal corticoids, however, influence more than the inflammatory process. They exercise extensive control over the level of minerals and sugar (glucose) in the blood. An imbalance in corticoid secretion is likely to have far-reaching effects on the body’s metabolism and on organs that are commonly damaged by metabolic disorders, notably the heart and kidneys. By administering the pro-inflammatory hormone DOC to white Leghorn chicks, for example, Hans Selye and his co-workers at the University of Montreal were able to produce degenerative changes in the kidneys, with ensuing high blood pressure, hardening of the blood vessels, and cardiac disease. During the course of the experiment, the DOCtreated chicks “began to drink much more water than the controls which were not given the hormone, and – gradually they developed a kind of dropsy. Their bodies became enormously swollen with fluid accumulations under the skin and they began to breathe with difficulty gasping for air, just like certain cardiac patients.” By degrees, Selye’s results and those of other researchers in the field began to include a large number of common chronic illnesses. Pro- and anti-inflammatory corticoids, it was found, seem to play roles of varying importance in diabetes, thyroid disorders, peptic ulcers, and psychic disturbances. The anti-inflammatory corticoids have been very useful in combating many of these illnesses. Cortisone frequently produces striking though temporary remissions in cases of acute leukemia, and the surgical removal of the adrenal glands often inhibits the growth of certain forms of cancer.
Selye has developed a general theory of stress from the data on the interplay of adrenal hormones. Stress consists of the physical changes within an organism which are caused by any environmental stimulus, whether it be heat, cold, infection, or a chemical irritant, and by the emotional disturbances we encounter in man. All living things have an adaptive mechanism that produces changes in the organism in response to changes in its environment. The adrenal corticoids in man and higher animals are essentially chemical agents that compel a living thing to respond internally to external stimuli. Every stimulus, desirable or harmful, produces a general stress reaction. Stress, in effect, is an important part of life.
But stress always results in a certain amount of “wear and tear” on the organism. “Many people believe that, after they have exposed themselves to very stressful activities, a rest can restore them to where they were before,” Selye writes. “This is false. Experiments on animals have clearly shown that each exposure leaves an indelible scar, in that it uses up reserves of adaptability which cannot be replaced. It is true that immediately after some harassing experience, rest can restore us almost to the original level of fitness by eliminating acute fatigue. But the emphasis is on the word almost. Since we constantly go through periods of stress and rest during life, just a little deficit of adaptation energy every day adds up-it adds up to what we call aging.”
No one, to be sure, can eliminate the “wear and tear” of life, but a reasonably clear distinction can be made between the “stress of life” and stress that results in ill health. Stress that results in ill health is severe, persistent, and one-sided. Selye has demonstrated that if stress is too severe, the resistance and life span of the organism are drastically reduced. An experimental rat may adapt itself for a time to a strong irritant, but the adaptation is made at a high price; longevity is decreased and general resistance is seriously impaired. If the animal is exposed to even minor but persistent stress, comparable to the ‘low-grade” nervous tension and anxiety usually found in modern urban man, it pays a similar price for adaptation. The animal is easily injured by irritants that ordinarily do not produce serious physical damage. The interplay of stress responses is so complex that the reader must turn to Selye’s own work, The Stress of Life, for a detailed discussion. In nearly all cases of severe or persistent stress, Selye has found evidence of thickened arteries, heart abnormalities, kidney damage, and increased blood pressure.
But Selye’s work also demonstrates that stress need not be harmful, provided it is balanced and varied. A sheltered, sedentary life that lacks a variety of stimuli produces an undeveloped, often inadequate stress mechanism as well as an undeveloped personality. A sheltered person has great difficulty in coping with many of the stimuli and irritants inevitably encountered in the normal course of life. If there is any notion that sums up Selye’s “stress of life” theory, it is the “pre-scientific” intuition that variety and balance-emotional, physical, and intellectual-are the bases not only for true individuality but for lasting health.
Selye’s plea for variety in life, however, rests on a well-thought-out hypothesis. Man, as a complex, multicellular animal, is composed of many organs and systems, each of which bears a different amount of stress. The organs that compose his body do not “wear out” evenly. Death invariably comes “because one vital part has worn out too early in proportion to the rest of the body…. The lesson seems to be that, as far as man can regulate his life by voluntary actions, he should seek to equalize stress throughout his being, by what we have called deviation, the frequent shifting-over of work from one part to the other. The human body-like the tires on a car, or the rug on a floor-wears longest when it wears evenly. We can do ourselves a great deal of good in this respect by just yielding to our natural cravings for variety in everyday life. We must not forget that the more we vary our actions the less any one part suffers from attrition.”
Conceivably, an informed individual can try to cultivate a mature outlook that will lend distance to the pettyirritations produced by the urban milieu. If circumstances permit, he can establish a personal regimen of after-work exercise and frequent excursions to the countryside. But on the whole, the metropolis exposes him to limited, intense occupational stimuli that produce an equally limited, intense stress response. A few organs continue to bear nearly the entire burden of daily life. Organs and systems that are not activated by modern forms of work and play are likely to be sheltered by the “conveniences” that the city affords. “One might question whether stress is peculiarly characteristic of our sheltered civilization, with all its comforts and amenities,” observe P. C. Constantinides and Niall Carey in a general discussion of Selye’s work. “Yet these very protections-modern laborsaving devices, clothing, heating-have rendered us all the more vulnerable and sensitive to the slightest stress. What was a mild stress to our forebears now frequently represents a minor crisis. Moreover, the frustrations and repressions arising from emotional conflicts in the modern world, economic and political insecurity, the drudgery associated with many modern occupations-all these represent stresses as formidable as the most severe physical injuries.”
The Problems of Overubanization
A number of urban problems have arisen that no city dweller can hope to solve or even meliorate on his own; they can be solved only by the community as a whole. One such problem, urban air pollution, has become very widespread and constitutes a serious hazard to human health. “Millions of citizens are living in an air ocean that is, on good evidence, unhealthy to breathe,” observes Herman E. Hilleboe, New York State Commissioner of Health. “Cities with the heaviest pollution load tend to rank high both in death and incidence rates for a number of diseases. This includes heart disease and cancer, the ranking killers and disablers of our time.” Among the new pollutants that will soon be added to our environment, Hilleboe warns, are “by-products from petroleum and from synthetic materials spawned by our fast-growing nuclear technology and from high-energy solid and liquid fuels. We are creating a new environment but we have not as yet done what is necessary to make this environment healthful and habitable for its people. Here again it is difficult to dramatize the matter of air pollution.”
The problem has been dramatized by cases in which air pollution reached the proportions of an emergency, comparable in many ways to an epidemic. Until fairly recently, serious cases of air pollution usually occurred in highly industrialized river valleys. Two such cases- one in the Meuse Valley in Belgium in I 930, which claimed sixty lives, and the other in Donora, Pennsylvania, in 1948, which killed twenty people-were due primarily to toxic fumes from metallurgical plants. To some degree, both could be regarded as industrial accidents, which could have been averted if suitable measures had been taken to control the effluents of local mills. A much greater respect for the potentially disastrous consequences of air pollution was created by the smog that descended upon London, a predominantly commercial city, during December 1952. Although the episode was brief, the daily death rate reached very high levels, comparable to those of London’s cholera epidemic in 1854 and its influenza epidemic in I9I8-I9.
At dawn on Friday, December 5, the air in London began to thicken perceptibly. Unusual weather conditions caused a heavy smog of urban pollutants to linger over the city for four days. During the first twenty-four hours the death rate doubled, the total for the day reaching 400 The next day, Saturday, it rose to 600, and on each of the two following days, Sunday and Monday, it soared to 900, although business and industrial activity was suspended on Sunday. On Tuesday, when the smog had already begun to lift, the number of deaths was 800, and the death rate remained high for several weeks thereafter.
The London smog claimed at least 4,000 lives. The majority of deaths occurred among infants and elderly people, but William P. Dowie Logan, Britain’s chief medical statistician, emphasizes that “it was by no means confined to the very young or the very old.” The death rate in the fifteen-to-forty-four age group increased about 50 per cent. Deaths from coronary heart disease rose from 118 in the seven-day period immediately preceding the incident to 281 in the week that followed it, while deaths from bronchitis soared from 76 to 704, almost a tenfold increase.
The possibility that a lethal smog comparable to the one that descended on London, will develop somewhere in the United States cannot be excluded. If the word “smog” is defined as air pollution that produces haziness in the atmosphere and irritation of the eyes, nose, and throat, then many American communities experience smog. The situation in Los Angeles is notoriously bad; the city is afflicted with fifty to seventy days of smog every year. Smog is found to a lesser extent in New York, Washington, Philadelphia, Boston, and other coastal metropolitan areas of the United States. The differences between smog in England and smog in the United States are due primarily to the differences in the irritants that pervade the air of the two countries. Air pollution in London is caused mainly by the combustion of coal whereas the principal irritants in Los Angeles are produced by the combustion of petroleum products. Experts have emphasized, however, that “in the London episode the air pollutants, when considered in terms of their human effects, closely resembled those present in the air of many large urban areas. These pollutants were quite similar to those of many other urban areas in that they are irritating to the exposed living membranes (of the eyes, nose, throat and respiratory tract). For example although Los Angeles air pollution is chemically different from that of London the two resemble each other in their effects on man since each causes irritation of exposed living membranes.”
Ordinarily, smog is episodic and localized. In the long run, a more serious problem is posed by persistent, low-grade air pollution, which is often imperceptible to the senses and changes relatively little from day to day. This form of air pollution is very widespread in the United States. Nearly IO,OOO communities, containing the overwhelming majority of the American people, have persistent air pollution problems. According to a recent report by the New York State Air Pollution Control Board: “Of the state’s 40 communities with populations of more than 25,000, only one had negligible air pollution. The combined survey data show that approximately three-fifths of the communities of 5000 to 25000 population and about one third of those with less than 5000 people had major or minor air pollution.” A survey of Texas by the U. S. Public Health Service showed that three quarters of the state’s communities with populations of more than10000 had “objectionable air pollution.”
Although patterns of air pollution vary from one community to another, it is generally agreed that the air in nearly all American cities contains a number of highly toxic substances, most of which are waste products of industrial plants, motor vehicles, and heating equipment. The solid particles in an urban atmosphere often include such highly toxic substances as lead, beryllium, and arsenic. Common air-borne gases and vapors include sulfuric-acid mist, sulfur dioxide, carbon monoxide, formaldehyde, oxides of nitrogen, ammonia, and scores of organic vapor contaminants. At least a hundred air pollutants have been identified, and the interaction of gases, vapors, and solid particles in the atmosphere produces many other compounds that have not been chemically analyzed. Several known toxicants that pollute the air are characterized by synergistic activity; they are more toxic together than when each is absorbed individually. For example, an effect that is more than additive is produced by the inhalation of carbon monoxide together with nitrogen oxide, two of the most common pollutants in the urban atmosphere.
The average individual breathes about 16,000 quarts of air daily. If he lives in an urban environment, his lungs receive about four times as many air contaminants as those of a rural dweller. John H. Ludwig, of the U. S. Public Health Service, suggests that repeated exposure to “relatively low levels of air pollution” may be involved in the development of chronic degenerative diseases, including skin and lung cancer, heart and vascular disorders, and chronic bronchitis. During periods when urban air pollution is at its height, the contaminants may worsen existing chronic diseases, especially heart disorders, by interfering with the passage of oxygen through the membranes of the lungs into the blood stream. Certain air pollutants may combine with body proteins to form allergy-inducing, or allergenic, substances and lead to increasing sensitization and allergic reactions.
If the possible consequences of air pollution listed by Ludwig seem to be farfetched, let us enumerate some of the contaminants produced by the automobile, the principal source of air-borne toxicants in large American cities. Nearly 80 per cent of the pollutants that produce smog in Los Angeles come from motor vehicles. In burning I,OOO gallons of fuel, an automobile discharges I7 pounds of sulfur dioxide, about I8 pounds of aldehydes (estimated as formaldehyde), 25 to 75 pounds of oxides of nitrogen (estimated as nitrogen dioxide), 200 to 400 pounds of complex organic compounds, and over 3000 pounds of carbon monoxide.
Sulfur dioxide is both an irritant and a poison. It is probably a major contributor to the high incidence of chronic bronchitis in England. There is evidence to indicate that a fairly low level of sulfur dioxide-“a level not infrequently found in air”-is sufficient to produce temporary spasms of the smooth muscles in the lungs. In “somewhat higher concentrations,” the compound produces severe inflammation and peeling of the respiratory membranes. Formaldehyde is a corrosive poison that not only irritates the respiratory membranes but also affects the central nervous system, and nitrogen dioxide is a highly toxic gas that is extremely dangerous even in such relatively low quantities as IOO parts per million.
Several of the organic compounds produced by the combustion of gasoline and diesel oil are carcinogenic. This has been clearly established by Paul Kotin, of the University of California. When tarry material from the exhausts of motor vehicles was painted on laboratory mice, skin tumors appeared in 50 per cent of the animals. The largest amount of carcinogenic substances, according to Kotin’s findings, is produced by slow-running and idling engines-that is, under conditions prevalent in areas with congested traffic (see pages 149-50).
A problem that has been largely ignored in the United States is the danger of chronic carbon monoxide poisoning. Until recently, conventional medical opinion held that carbon monoxide (CO) is rapidly removed from the blood stream. Few physicians regarded the enormous output of the gas by motor vehicles as a danger to public health. According to recent reports, however, carbon monoxide may be retained by the body for relatively long periods of time, perhaps as much as several weeks. The problem has aroused a great deal of concern in Europe, where the conviction is growing that chronic carbon monoxide poisoning is a serious hazard of the automobile era. In the United States, Richard Prindle, of the U. S. Public Health Service, emphasizes that “in a community in which carbon monoxide levels exist, 24 hours a day, seven days a week, for the lifetime of an individual, chronic CO poisoning is a distinct possibility.” We need only consider the fact that smoking produces a definite level of carbon monoxide in the blood “to realize that coupling this with frequent, although fluctuating exposures to CO in the ambient air . . . might well lead to serious consequences in a large population.”
Another problem that cannot be solved without the co-operation of the entire community is water pollution. Water is a traditional medium for the transmission of germs and toxic substances. During the past three generations vigorous efforts on the part of medical and public health officials have enormously reduced the hazard created by water-borne infectious agents, but today old problems of pollution are beginning to recur and new ones to appear, especially in communities that obtain the
greater part of their drinking water from rivers. Although Americans tend to make a fetish of cleanliness, an appalling amount of untreated or inadequately treated urban sewage is discharged into river water-water which is often taken up again for public consumption by communities downstream. Added to urban sewage are wastes from chemical factories, slaughterhouses, and metallurgical plants. Although sewage and industrial wastes have produced local public health crises in the past, the postwar expansion of cities and metropolitan areas is turning water pollution into a grave national problem, comparable in many respects to that created by urban air pollution.
Attempts by federal, state, and municipal authorities to control the contamination of our water are complicated by frequent changes in the composition of industrial and urban wastes. Today drinking water may contain a wide variety of new bleaches, detergents, petrochemical and metallurgical wastes, insecticides, dyes, and radioactive compounds. Few if any of these contaminants are removed by ordinary methods of water purification.. Rolf Eliassen, of the Massachusetts Institute of Technology, points out that the “exotic organic chemicals” discharged by petrochemical plants into streams “are not even detected by present conventional means of water analysis.” Neither industry nor pollution-control laboratories have been able to form a reliable picture of the long-range effects of the newer pollutants on public health. “Let us all be honest with ourselves,” declares Robert A. Kehoe. “Specifications for human health and welfare, in relation to the common contaminants of many of our sources of water, do not exist, and we shall not be able to deal effectively with this problem of public health until they can be formulated on sound physiological facts.”
At the same time, the traditional problem of waterborne infections is gaining greater significance.. Many cases of acute illnessess are being attributed to polluted drinking water. To cite a few examples: In 1957 the number of cases of infectious hepatitis began to increase markedly in Nebraska. The disease, an acute inflammation of the liver, was found predominantly in the eastern part of the state. The outbreaks occurred primarily in urban communities that obtain their drinking water from the highly polluted Missouri River. Although most public health officials tend to be extremely cautious in their comments, Nebraskan authorities made no attempt to conceal their suspicion that the increase in hepatitis cases was due to drinking water contaminated by sewage from upstream communities. Similar explanations have been given for polio epidemics in Salt Lake City and in Edmonton, capital of the Canadian province of Alberta. (Much of the evidence pointing to polluted water as the cause of these outbreaks is circumstantial, but there is no longer any doubt that hepatitis can be communicated by water as well as by personal contact. The Edmonton outbreak suggests that poliomyelitis can also be transmitted by water. Edmonton obtains its drinking water from the Saskatchewan River and the epidemic could be related to a failure of the sewage system at a town upstream.) Both diseases are caused by viruses that are found in human feces and sewage.
True, water-borne diseases and, in some communities, urban air pollution have been more serious in the past than they are today. In 1832, Asiatic cholera spread from Quebec to New York City, where it claimed thousands of lives. Cholera persisted in the city for decades before it was eradicated. Typhoid fever, another waterborne disease, was found everywhere during the last century. Owing to improved methods of public sanitation, the incidence of the disease is now negligible. Similarly, many of the worst pockets of urban air pollution are being “cleared up,” to the extent of eliminating some of the dense soot and smoke. The cloud of industrial soot that began to descend on Pittsburgh as early as the 1860’s has been lifted. Although Pittsburgh does not enjoy pure air, a reduction has been achieved in the more offensive pollutants that once filled the city’s atmosphere. Air pollution programs have gained ground primarily against the smoke and grime of the old Industrial Revolution, just as social reform has scored its greatest triumphs over illiteracy and child labor.
Since World War II, however, there has been a new industrial revolution, and the problems of urban life have acquired new dimensions. On the one hand, the sources of urban pollution have increased in number and variety; many pollutants, such as those produced by the automobile, are difficult to manage, even where everyone is willing to co-operate on the problem. On the other hand, metropolitan regions are being burdened beyond their capacity to cope with air pollutants and to meet the need for clean water. Their waterways and atmosphere are expected to absorb a staggering quantity of waste products from industrial plants, homes, and vehicles. Currently the United States must dispose of over 18 billion pounds of sewage solids every year, an increase of 70 per cent in the past two decades. The water table in many areas of the United States is being lowered by the voracious demands of highly concentrated populations and expanding industries. At the same time that the number of pollutants has increased, the ecological preconditions for wholesome air and plentiful water are being undermined. A major disequilibrium is arising between town and country, industry and the biotic environment, and population and regional resources.
Rene Dubos, of the Rockefeller Institute for Medical Research, places smog among the major environmental factors that have unleashed the “Apocalyptic horsemen” of modern disease. According to Dubos, St. John the Divine’s vision on the isle of Patmos is symbolic of present-day urban and industrial life. The first horsemen of the Apocalypse to be seen by the saint were Famine and Pestilence. “Then another, even more terrifying visitation was sent by the angered Deity,” Dubos recalls. “After the fifth angel had sounded his trumpet he opened the bottomless pit and ‘there arose a smoke out of the pit, as the smoke of a great furnace; and the sun and the air were darkened by reason of the smoke of the pit.’ And out of the bottomless pit came the scorpions that did not kill men but tormented them for five months before final destruction came ‘by the fire, and by the smoke and by the brimstone.’ The time of fulfillment of the Apocalypse may not be far off.”
Dubos is not being overly dramatic. We are producing a new spectrum of environmental hazards whose full effects still await the passage of time. The trends are not encouraging. “Many diseases that are thought to be associated with, or caused by, air pollution have been increasing over the years,” Prindle writes. “Included amongst these are the respiratory cancers, emphysema, chronic bronchitis, and cor pulmonale. (Emphysema is a pulmonary disorder that often leads to cor pulmonale, a common form of heart disease. Emphysema has become a major disease in London, ranking third (following heart diseases and cancer) as a cause of death among middle-aged males. The increase in emphysema cases, both in London and Los Angeles, is attributed by many medical authorities to air pollution.) If air pollution continues to increase, one can only conjecture that this rising incidence of disease will continue and that the effect upon the health of the nation-and over the technologically-expanding world-may be severely augmented. The overall effect of air pollution on the economy, the health, and the welfare of the people may become a disaster.”
The effects of air pollution on public health will be difficult to judge for many years to come. A large number of adults straddle two worlds. They were born and raised in communities that have only recently acquired the features of metropolitan life. The early years of their lives were spent in the pre-nuclear age. But it is difficult to ignore the portents found in the high incidence of chronic diseases in all age groups of the population. Without a basic solution to the problems of urban life, Dubos’s apprehension may Dubos’s apprehension may prove to be amply justified.