Cancer Risks

Exposure to several substances found in the home can increase the risk of cancer, which is the second leading cause of death among adults and children in the U.S. According to the American Cancer Society, environmental factors including tobacco, chemicals, infectious diseases, and radiation are responsible for three-quarters of all cancer deaths in the U.S. While many adult cancers can be traced to these environmental factors, the causes of most childhood cancers are unknown. Like many environmentally related diseases, cancer takes a greater toll on African-Americans, who are more likely to develop and die from cancer than persons from other racial and ethnic groups.

According to the American Cancer Society, smoking, unhealthy diet, and physical inactivity play a greater role in determining cancer risk than exposure to trace levels of pollutants in food, air, and drinking water. However, the degree of risk from chemical exposure depends on the concentration and duration of exposure. Individuals exposed to high concentrations of cancer-causing substances bear a significantly higher risk of developing cancer. At the same time, widespread exposure to low concentrations of carcinogens can increase the risk of cancer across the population as a whole. For environmentally related cancers, ten or more years typically pass between exposure to cancer-causing substances and detectable cancer.

Several substances that may be found in or around the home, such as radon, some pesticides, asbestos, formaldehyde, and arsenic, are known carcinogens. Becoming aware of these substances and their potential risks is the first step in reducing potential exposures.


Radon, a naturally occurring radioactive gas produced by decaying uranium, is the second leading cause of lung cancer after smoking. EPA estimates that radon is responsible for approximately 21,000 lung cancer deaths per year. Smoking has been shown to increase the risk of lung cancer in those exposed to radon.

Radon gas enters homes through dirt floors, cracks in concrete walls and floors, floor drains, and sumps. Any home may have a radon problem—new or old, well-sealed or drafty, with or without a basement.

Because radon is colorless and odorless, it is necessary to measure radon levels in the home in order to determine the extent to which it is present. EPA provides guidance regarding the risks associated with different levels of exposure and recommends corresponding corrective actions.


Exposure to some pesticides also may increase a person’s risk of cancer. Pesticides are commonly used in and around the home to control insects, termites, rodents, and fungi, as well as to disinfect. According to surveys cited by EPA, 75 percent of U.S. households use at least one pesticide product over the course of a year, and 80 percent of most people’s exposure to pesticides occurs indoors. During 2001, the American Association of Poison Control Centers reported that nearly 50,000 children under age six were exposed to pesticides.

The health impact from exposure to pesticides varies depending upon the level and duration of exposure. Immediate impacts may include skin, eye, and respiratory tract irritation; headaches; dizziness; visual disorders; and memory impairment. Many pesticides are known to cause cancer in animals, and some are suspected or known to cause cancer in humans. Some studies have demonstrated a link between childhood cancers and pesticides.


Exposure to asbestos also increases the risk of developing cancer. Asbestos can cause lung cancer, mesothelioma (cancer of the chest and abdominal linings), and asbestosis (irreversible and potentially fatal scarring of the lung). As is the case with radon, smoking significantly increases the risk of cancer in those exposed to asbestos. The health impacts of asbestos typically appear 20 to 30 years after exposure.

Asbestos may be found in a number of locations in the home. Until the 1970s, many building products and insulation materials contained asbestos, including insulation on steam and furnace pipes, ducts, and boilers; vinyl, rubber, or asphalt floor tiles; soundproofing or decorative material sprayed on walls or ceilings; and roofing, shingles, and siding. Today, asbestos-containing products must be labeled.

As a general rule, asbestos that is in good condition does not pose a risk and should be left undisturbed. If disturbed, asbestos material may release asbestos fibers, which can be inhaled into the lungs and increase the risk of disease.

Other substances around the home that may increase the risk of cancer include formaldehyde (found in pressed-wood products), which is used largely for new construction, and arsenic (present in most pressure-treated wood manufactured before prior to 2002), which was widely used for decks and playgrounds.

Sources and Additional Information:

American Cancer Society –

American Lung Association –

Biological Effects of Ionizing Radiation (BEIR) VI Report: “The Health Effects of Exposure to Indoor Radon” –

Cancer Information Service –

CureSearch –

Rachel Carson Council, Inc. (information on pesticides) –

Silent Spring Institute –

U.S. Environmental Protection Agency, Asbestos in Your Home –