Cancer is any of more than 100 diseases characterized by excessive, uncontrolled growth of abnormal cells, which invade and destroy other tissues. Cancer develops in almost any organ or tissue of the body, but certain types of cancer are more lethal than others. Cancer is the leading cause of death in Canada and second only to heart disease in the United States. Each year, more than 1.2 million Americans and 132,000 Canadians are diagnosed with cancer, and more …showed first 75 words of 1210 total…

…showed last 75 words of 1210 total…X rays, accounts for about 2 percent of all cancer deaths (see Radiation Effects, Biological). Most cancer deaths from radiation are from skin cancer, which is triggered by too much sun exposure. Air pollution, water pollution, and pollutants in the soil account for about 2 percent of all cancer deaths in the country, particularly due to lung and bladder cancer. Lung cancer rates are generally higher in cities, where increased industry and automobile traffic produce air pollution.