Cancer is a group of diseases in which abnormal cells in the body grow out of control. Cancer is not just one disease but many different diseases. Cancer is one of the most common chronic diseases in the United States, second only to heart disease as the leading cause of death.
Cancers generally develop gradually as a result of a complex mix of factors related to lifestyle choices, environment and genetics. Each type of cancer is caused by a different set of factors, some well-established, some uncertain, and some unknown. The exact causes of most cancers are unknown, and research continues to examine how and why normal cellular growth becomes uncontrolled. Different types of cancers in a community or workplace do not necessarily have the same cause.
Most cancers are due to factors related to how we live. Tobacco use, heavy drinking, a poor diet, physical inactivity, obesity and overexposure to sunlight increase the risk for cancer.
Through surveillance and tracking, scientists have identified trends in cancer that sometimes correlate with the presence of certain environmental contaminants. This correlation does not rule out other causes, but suggests that environmental factors may increase the risk for particular cancers.
Risk Factors Associated with Cancer
Cancer is a disease with many risk factors; those factors can affect the illness in ways that are not fully understood. Most cancers take a long time to develop. Studies have documented that it may take as long as 40 years for some cancers to develop after exposure to some substances, depending on the type of cancer.
Although environmental contaminants have been a source of great public concern for decades, few community-level environmental exposures have been well studied. The cancer risks associated with many environmental chemicals have been identified through studies of workers who have had higher occupational exposures to these chemicals than the general public. The evidence is building to support a link between cancer and exposures to certain environmental contaminants.
Reducing Risk of Cancer
Some environmental exposure is potentially avoidable. For example, some risk factors, such as smoking, are alterable. Other factors, such as a person's age, race, or genetics are predetermined. Having a risk factor does not mean that cancer will develop and many people who get the disease may not have had any known risk factors. Making healthy lifestyle choices and taking precautions at home and in the workplace to reduce potentially harmful exposures can help prevent cancer. To reduce risks, people are advised to:
- Discuss colon cancer screening with your doctor;
- Discuss other specific recommendations, particularly if a history of cancer exists in your family;
- Do not smoke, dip, or chew tobacco;
- Eat at least 5 servings of fresh fruits or vegetables a day;
- Exercise at least 5 times per week;
- Limit alcohol consumption;
- Men, get yearly physical exams and examine testes as recommended by your doctor;
- Protect against sun exposure and avoid getting sunburned;
- Reduce fat consumption; and
- Women, examine breasts monthly and get regular breast examinations, mammograms, and Pap smears.