Many lifestyle changes can be made to help prevent cancer: stop smoking or never start; eat a healthy diet; exercise; and learn healthy ways to cope with stress. But exposure to air pollution is a risk factor for cancer beyond individual control and requires public will to change.

Cancer-causing substances in the air
According to data published by the U. S. Environmental Protection Agency (EPA), more than two billion pounds of toxic chemicals, including known and suspected carcinogens – cancer-causing substances – are released into the air each year from petrochemical facilities, power plants, incinerators and other industrial facilities. Exposure to carcinogens can be intensified when fine dust and soot particles in the air act as tiny sponges to soak up toxic substances and carry them deep into the lungs. Recent studies have found that toxin-soaked ultrafine particles can even make their way through the blood brain barrier, into the brain and bloodstream.

In 2001, Environmental Defense’s Scorecard ranked Harris County in the top 10 percent of all counties in the U.S. as the “dirtiest/worst” for total environmental releases. Emissions from the petrochemical facilities in the Houston-Galveston area included more than 2 million pounds of carcinogens such as benzene, chloromethane, 1,3-butadiene, formaldehyde, trichloroethylene, lead compounds and others.

Cancer cells develop slowly
Breathing polluted air may seem harmless. Some pollutants are invisible and odorless, and may not cause discomfort when they enter the body. The damage caused by toxins, particulate matter and ozone takes time.

Exposures to air pollutants can start a series of changes that eventually upset the body’s natural regulation of cell growth. When cell growth is out of control, transformation of a normal cell occurs in stages. It may take many years before the normal cell becomes a cancerous cell. For example, a person exposed to asbestos in their 30s may not be diagnosed with lung cancer until they are in their 60s. Even more insidious is the fact that parents exposed to certain carcinogens may have no symptoms, but their children may inherit genes that predispose them to cancer.

Who’s at risk of developing cancer?
The risk of developing cancer from exposure to carcinogens depends on the potency, persistence and concentration of contaminants involved. The route, duration and frequency of exposure also are factors. A person exposed daily to very high levels of a potent carcinogen is more likely to develop cancer than someone who has less frequent exposure, or is exposed to lower levels or less potent carcinogens.

Another risk factor is gene susceptibility. There is increasing evidence that an individual’s susceptibility or resistance to cancer may be determined by genetic factors, or gene-environment interaction. These gene variants do not become risk factors for cancer unless they are damaged by carcinogens.

More research is needed to determine what combinations of factors predispose people to cancer. Currently, scientists at the National Institute of Environmental Health Sciences at The University of Texas Medical Branch in Galveston are conducting research on toxicogenics – the collection, interpretation, and storage of information about gene and protein activity in order to identify toxic substances in the environment. This information may determine delayed long-term effects of multiple chemicals, and help treat people at the greatest risk of diseases caused by environmental pollutants or toxicants.

Cancer risks for children inside and outside the womb
Cancer is the leading cause of death by disease among children. Leukemia, lymphomas, and tumors of the brain and nervous system are among the most commonly occurring cancers in children under 14 years of age. Furthermore, these types of cancer are increasing.

Epidemiologic studies have shown a connection between childhood cancer risk and exposure of the parent or child to several different environmental chemicals, including pesticides, industrial chemicals and drinking water contaminants.

Children are more vulnerable to carcinogens than adults because they are often more highly exposed than adults; their systems are unable to detoxify many chemicals; and their rapidly developing bodies are highly vulnerable to effects of carcinogens and other toxic chemicals. Higher rates of cell growth during early development increase the potential for environmental carcinogens to disrupt development at critical periods. Many cancers diagnosed in childhood and early adulthood may result from genetic mutations that either are inherited or occur while in the womb.

Health effects of air pollution studies lacking in Texas
Studies have been conducted in California, the United Kingdom and in other parts of the world that show a connection between increase in cancer rates and air pollution. These studies help support the need for industry to initiate or improve pollutant emissions monitoring and control. Such studies are glaringly lacking in Texas.

The last major study of specific populations and risks from air pollution in Texas was conducted by Eleanor Macdonald, one of the country’s first epidemiologists hired by M.D. Anderson Cancer Center in 1948. Macdonald examined 180,000 death certificates and discovered high cancer death rates in neighborhoods downwind of the Houston Ship Channel. Her study confirmed that Houston cancer death rates were tied to air pollution. But the study was ignored by the medical establishment, and no serious study on the health effects of air pollution in the Houston area or Texas has been conducted since then.

Without studies showing a need for emissions monitoring and reduction in the vicinity of the world’s largest concentration of petrochemical plants and refineries, polluters are not required to make changes that could reduce air pollution and improve the health of people living in the Houston-Galveston area.

Industry won’t clean up without the Clean Air Act
In addition to the lack of studies and action to clean up the air locally, the weakening of the Clean Air Act by the Bush Administration and the EPA will let industry continue to shirk responsibility for dumping carcinogens and other toxins into the air. The weaker rules take away the requirement for facilities to install modern pollution controls whenever they make significant modifications.

Take Action
Let your elected representatives nationally and locally know that you are concerned about the health effects of air pollution. To contact the Houston City Council, go to the City of Houston Government Center web site at http://www.ci.houston.tx.us/citygovt/council/. The site has phone numbers and E-mail listings for each council member. Or write to your Council Member at: 900 Bagby, City Hall Annex Floor, Houston, TX 77002.

For contact information on your state and national representatives, go to “Find Your Incumbent” at http://www.capitol.state.tx.us/fyi/fyi.htm . Support your local environmental organizations that work to increase awareness and take action against environmental abuses.

Take care of yourself and your family

• Don’t smoke, and don’t allow smoking in your home – avoid breathing other smokers’ smoke.
• Eat a healthy, well-balanced diet. The American Cancer Society recommends lots of fresh fruits, vegetables and whole grains.
• Limit consumption of high-fat foods, particularly fats from animal sources to limit exposure to pollutants that tend to accumulate in fatty tissues, such as dioxin and PCBs.
• Reduce exposure to pesticides by eating organically grown fruits and vegetables whenever possible.
• Get at least 30 minutes of aerobic exercise daily, learn healthy ways to cope with stress and get plenty of rest.
• Find less toxic alternatives to using pesticides in your home, lawn and garden.
• If you do use pesticides, carefully follow instructions and avoid using them around infants and small children or during pregnancy.
• Ask about pesticide use at your child’s school and urge schools to use the least toxic alternatives.
• If your child rides a bus to school, suggest that the school use non-diesel fuels to reduce your child’s exposure to harmful particulates.