Some of cancer’s many triggers are carcinogens in the environment. Knowing the facts can help reduce the risk.
Cancer arises from the transformation of normal cells into malignant tumors. These changes can result from interaction with three categories of external agents, including:
Physical carcinogens, such as ultraviolet and ionizing radiation;
Chemical carcinogens, such as asbestos, components of tobacco smoke, aflatoxin (a food contaminant), and arsenic (a drinking water contaminant); and
Biological carcinogens, such as infections from certain viruses, bacteria, or parasites
Of the nearly 10 million deaths from cancer in 2020; the most common (in terms of new cases of cancer) were:
Breast (2.26 million cases);
Lung (2.21 million cases);
Colon and rectum (1.93 million cases);
Prostate (1.41 million cases);
Skin (non-melanoma) (1.20 million cases); and
Stomach (1.09 million cases).
The most common causes of cancer death in 2020 were:
Lung (1.80 million deaths);
Colon and rectum (935,000 deaths);
Liver (830,000 deaths);
Stomach (769,000 deaths); and
Between 30 and 50% of all cancers can currently be prevented by avoiding risk factors. Cancer risk can be reduced by:
Avoiding tobacco use;
Eating a healthy diet, including fruit and vegetables;
Avoiding alcohol abuse;
Avoiding ultraviolet radiation (mostly from exposure to the sun);
Limiting exposure (as far as is possible) to ionizing radiation from occupational or medical diagnostic imaging)
Reducing exposure to outdoor air pollution and indoor air pollution, including radon.