... some important links between exposures and cancer. It is often difficult to determine what chemicals people were exposed to many years earlier, to what degree they were exposed, and which specific ... symptoms are NOT always caused by cancer. It is important to see a doctor about these or other physical changes that continue for some time. However, certain cancers have no obvious symptoms, ... could be harmful, talk to your doctor about the need for each X-ray and the use of shields to protect other parts of the body. ■ Check your home for high levels of radon. Radon levels in a home...