Keeping a home safe usually is thought to mean having locks on doors and windows, alarm systems and maybe a German shepherd, just in case. Few Americans think of aerosol cans, insect poisons and old paint cans as threats to their health and the environment.

Mary Lamielle of Voorhees, N.J., remembers being sensitive to chemicals growing up. As an adult, she noticed sinus problems, headaches and burning in her nose and throat while remodeling her home. After exposure to chemicals from a nearby sewage treatment plant and from a gasoline spill, she had muscle and joint pain, chronic headaches, dizziness and problems with short-term memory.

"I got sicker and sicker," said Lamielle, director of the Environmental Health Association of New Jersey. "The sicker I got, the more I stayed at home in the bedroom."

Doctors diagnosed her with a variety of medical ills from chronic viral infection to problems with her immune system. But Lamielle believes her sickness was caused by the chemicals she was in contact with.

The National Academy of Sciences estimates that 15 percent of the American population has an increased "allergic sensitivity to chemicals commonly found in household products such as detergents, solvents, pesticides, metals and rubber, placing them at increased risk for disease." While few are likely to react with the severity that Lamielle reports, many people could benefit from limiting their exposure, experts believe.

In 1980, the Environmental Protection Agency (EPA) conducted a study assessing people's exposure to toxic chemicals. Researchers looked at 600 homes in four states: New Jersey, California, North Dakota and North Carolina.

"Our thought in 1980 when we were looking at cancer-causing chemicals was that highly industrialized areas would have the most problems," said Lance Wallace, an environmental scientist with EPA's Office of Research and Development.

The results of the study, completed in 1986, were surprising. EPA found that people were exposed to higher levels of toxic chemicals inside their homes than outside.

Of the following chemicals looked at in the study, benzene, found in gasoline and petroleum products, is known to cause leukemia in people. The rest cause cancer in mice and rats and are suspected of causing cancer in humans, Wallace said. :: Benzene. Smokers are highly exposed to this chemical because it is produced when a cigarette is lit. EPA found that benzene levels were three times higher in homes where people smoked. :: Para-dichlorobenzene. People who use moth balls and room air freshners or deodorizers are exposed to this chemical, which exists as an invisible gas at room temperature. The solid form slowly vaporizes over time. EPA found this chemical to be 50 times higher indoors and estimates that out of the 85 million homes in the country, 30 million or more have some level of it present. :: Chloroform. In 1970, people were found to have chloroform in their blood. EPA passed the Safe Water Drinking Act in 1974, limiting the amount of chloroform that could be put in drinking water. In the 1980 study, chloroform was also found in the air of people's homes. It is released from water into the air, particularly when water is heated. EPA estimates that the average person uses 200 liters of water a day. Each person drinks about one to two glasses a day and uses about 50 liters in the shower. EPA found chloroform levels to be five times higher in the home than they were outside. :: Tetrachloroethylene. This is the chemical solvent used by 85 percent of the country's dry cleaners to clean clothes. EPA found the level of exposure to be five times higher in homes than outside. Other toxins to watch out for are: :: Formaldehyde, a carcinogenic gas, used in new carpets and drapes, fungicides, air freshners, cosmetics and toothpaste; :: Lindane, a pesticide used in many garden products, shelf paper, anti-lice shampoos and pet products; :: Dichlorvos, used in animal flea collars, no-pest strips and insect-killer sprays; :: Chlordane, used in termite products; :: Fungicides, used on lawns, fruit trees and rose gardens to kill fungus and also found in antifungal shampoos for pets and humans.

What can people do to rid their homes of toxic chemicals? Labels on some products can help, but not all manufacturers list the ingredients.

Debra Lynn Dadd, a self-described consumer advocate, provides practical advice for homeowners in her two books "Nontoxic & Natural" and "The Nontoxic Home" (Jeremy P. Tarcher Inc., $9.95 each).

Before throwing out household cleaners and pesticides, Dadd suggests finding ways to properly dispose of these items, which are toxic to the environment.

"Call your local public health department, environmental health department, department of health services or sanitation department to see if you have a hazardous-waste disposal program in your community," writes Dadd. "It may be illegal to dispose of certain products with your normal household garbage."

Resources

EPA has a national hotline number for people who want information on hazardous household wastes: (800) 424-9346. In the District, 382-3000.

For copies of Dadd's books, send $11.95 per book to: P.O. Box 1769, Loss, Calif. 94957.