Stress, Health Factors Are Part of Growth Control Issue

Among the many arguments being waged for or against control of urban growth, medical aspects receive scant attention.

Admittedly, certain urban health risks are already well-recognized--violence and homicide, drugs, AIDS, air pollution. But one pervasive characteristic of urban life--stress--is generally considered only an annoyance, a factor that detracts primarily from the quality of life.

Not so. Stress increases adrenaline levels, cholesterol, blood pressure, heart rate and the blood’s ability to clot--factors that increase the incidence of atherosclerosis, heart attacks and strokes.

It also leads to social and family destabilization, the abuse of alcohol and drugs, violence and suicide, and a host of secondary social and psychological ills. A large body of medical evidence now indicates that stress causes significant disease of body and mind and increased mortality rates.

Among the many causes of urban stress are noise (airport, traffic, sirens, factories); commuting and traffic congestion; crowding; air pollution; bright lights and higher temperatures; information overload; crime and safety problems; increased regimentation (i.e. one-way streets, limited access to freeways and signs prohibiting all sorts of behavior.)

Cardiovascular disease accounts for more than half of all deaths in the United States. For many years elevated blood cholesterol, smoking and hypertension were the major recognized risk factors.

There is now good evidence that stress is also an important risk factor. For example, stress increases the tendency of blood to clot, which in turn increases the likelihood of a heart attack. A study of accountants who were faced with the April 15 tax deadline showed that stress directly increased blood cholesterol.

When stressed, individuals with coronary heart disease--particularly those with Type A personality (hostile, competitive, rushed)--have more severe cardiovascular reactions than their non-coronary prone counterparts. The April 21 issue of the New England Journal of Medicine contained a landmark article demonstrating that even minor mental stress often decreases cardiac function in patients with coronary artery disease.

In a number of studies, individuals with Type A behavior patterns have been found to have a two- to three-fold increased incidence of coronary artery disease in comparison to those without Type A patterns. Stressed and/or Type A individuals are also thought to be more susceptible to sudden cardiac death from coronary artery spasm and arrhythmias. As expected, Type A personality has been found to be more prevalent among urban than rural dwellers, and seems to be more frequent under conditions of crowding.

Numerous animal experiments support the above observations. A 1987 study on monkeys, for example, studied the effects of stress and aggressive behavior. Stress was usually produced by reorganizing groups of monkeys, which disrupted social relationships and led to intense competition and fighting.

In dominant monkeys, it was found that coronary atherosclerosis was about twice as severe in those that had undergone stress as in those that had not. On the other hand, dominant monkeys that were not stressed did not show increased atherosclerosis when compared with non-dominant monkeys.

One of the driving forces behind the growth-control movement seems to be the problems of driving itself. The recent spate of highway shootings is one dramatic expression of the stress of traffic congestion.

A number of studies conducted during the 1960s demonstrated that the stress of driving increased the heart rate very significantly, and increased the blood levels of adrenal (stress) hormones. Physiological effects were similar in both drivers and passengers, suggesting that stress, and not the exertion of driving, was responsible. A 1979 study demonstrated a correlation between blood pressure and increased commuting distance or decreased commuting speed; another study showed increased blood pressure among urban bus drivers.

Heavy traffic is particularly stressful for several reasons:

* Drivers are often hurried, and are thus pre-stressed.

* Traffic jams combine helplessness with confinement in a small space surrounded by crowds (other trapped cars), a condition somewhat analogous to studies of prison crowding, where the effects of human crowding have been shown to be disproportionately severe.

* An estimated 2,000 decisions must be made per mile driven, leading to information and mental overload.

* The risks of an accident activate defense reactions.

* Drivers are subject to more automobile noise and pollution.

A number of important studies have shown a relationship between urban noise (automobile and airplane traffic, sirens, industry) and stress and disease.

Amsterdam conducted one such study when it was planning to expand its airport in 1968. An early survey estimated that, of about 400,000 people living in areas with much airport noise, 100,000 would suffer “unbearable nuisance.” Physiologic studies were conducted on volunteers, who were exposed to simulated airport noise (takeoff and landings of seven DC-8s or 747s per 15 minutes). Blood pressure rose 4% to 8%, respiratory rate by 7% to 38%, and errors on simple mental tests increased by 95%. Similar effects were produced by simulated noise of traffic or factories.

Examination of doctors’ office records from the airport area revealed that individuals in the flight paths had 50% more cardiovascular disease than those outside the flight paths, after correction for other factors. High blood pressure was 72% more frequent and visits to doctors and psychosomatic complaints were two to three times more frequent in areas with greater noise.

Similar results were reported after a Los Angeles study, where children living under the airport flight paths had higher blood pressure than children in control groups. Also in Bonn, high blood pressure was found to be 50% more prevalent in areas of high traffic noise.

Another interesting portion of the Amsterdam study considered the consumption of medications. The use of medical drugs in two nearby villages had been comparable in the early 1960s. Following the airport expansion, noise increased markedly in one village, where sales of sleeping pills, sedatives, antacids and cardiovascular drugs doubled. The other village remained quiet and drug usage remained stable.

A few other urban stress-disease relationships can be mentioned before concluding. There is evidence that stress leads to impotence, especially in men who already have some underlying vascular disease. Studies suggest that stress also impairs resistance to infection. Stress plays a causative role in alcoholism, drug abuse and suicide, and probably contributes to some psychiatric disorders. Harmful effects of air pollution--respiratory diseases, lung cancer--have already been widely publicized.

In summary, urban living produces disease of body and mind, both benign and lethal. In already large urban areas, medical consequences constitute an important argument in favor of firm policies of growth control.