Medical problems caused by environmental hazards in the home are far-reaching. They range from respiratory ailments - stuffy nose, itchy throat, wheezing, shortness of breath - to more usual complaints of ear infection, asthma, and bronchitis. Such subtle symptoms as fatigue, headaches, inattentiveness, and dermatitis are possible reactions to an unhealthy environment. If you're a young adult who does not smoke, drink alcohol, or take drugs, and if you eat nutritionally, get enough sunlight, and exercise daily, the toxins at home may not affect you. But if you are a little child,

a pregnant woman, or over 60, or spend more than 12 hours a day at home, a few chemical toxins in the home can change your life. People suffering from bronchitis, allergies, or heart problems are affected, too. A constant diet of environmental toxins puts physical stress on the human body. Add to this the emotional stress of hassles on the job, constant noise, and bad relationships, and you've got a human machine that is ripe for ill health. Such a condition stretches the limits of human adaptability.

The most dangerous are chronic delayed reactions. These result from almost daily exposure building up over time and can range from neurological damage (from eating lead paint or drinking lead-contaminated water, for example) to the risk of cancer from exposure to radon, asbestos, and chemicals in the air and water. Smoking, of course, hastens the ill effects.

Acute reactions (the opposite of chronic) occur shortly after exposure to high levels of contaminants. They may be just as severe, but they are easier to detect and signal that something is not

agreeing with you. You may develop a rash or headache, for example, soon after bathing or showering in heavily contaminated water. Some people react more quickly to contaminants than others do. People who wear contact lenses, for example, often are bothered by environmental toxins in the air before anyone else is. Allergic people and those with respiratory problems are often among the first to notice irritating symptoms. But the people who have the most difficulty living in the 20th century are the chemically sensitive. For them, such ubiquitous phenomenon as car exhaust, smog, formaldehyde in carpeting and building materials, hydrocarbons in vinyl furniture, perfumes, detergents, and fabric softeners cause severe problems.

A controversial branch of medicine has evolved to treat those people who are acutely sensitive to environmental toxins. Called Clinical Ecology, this branch of medicine treats people with allergies and more severe ailments as symptoms of poisoning. Though Clinical Ecologists have few friends, acceptance in the scientific community is growing. Arguing in its defense, Al Levin, a prominent San Francisco physician, told Science magazine (December 19,1986) that Clinical Ecology is only in the early stages of development, as radiation research was in the

1940s. "It took 15 to 20 years for people to realize that ionizing radiation was linked to a higher incidence of cancer." In time, Levin says; his field will be respected.

One theory about hypersensitivity is that the chemicals that irritate hypersensitives are poisonous to everyone - but most people never know it. It is possible that low levels of certain chemicals are harmful to everyone, and the chemically hypersensitive individual simply shows damage more readily - like canaries in a coal mine, they're the first to show the ill effects of a poisoned environment. There is growing evidence that the levels of chemicals we used to think are safe are really not. Many scientists agree that for chemicals that may cause cancer or other chronic diseases, there is no level of exposure so small that there is no danger of developing the disease. The lower the concentration of chemicals, the lower the risk.