Final answer:
Carcinogens are substances or radiations that cause cancer by inducing mutations in DNA, and exposure can contribute to various cancers. Chemical carcinogens, such as those in tobacco smoke and processed meats, along with lifestyle factors, greatly increase the risk. Lung cancer, though not the most common, leads in cancer deaths due to its severity.
Step-by-step explanation:
The term carcinogen refers to any substance or radiation that can cause cancer, which is characterized by the uncontrolled growth and spread of abnormal cells. Chemical carcinogens may include compounds found in tobacco smoke, certain industrial byproducts, processed meats, and other substances such as asbestos, benzene, and numerous toxic metals. Exposure to carcinogens may lead to mutations in DNA during cell replication or through their metabolites.
Examples of carcinogens include cigarette smoke, which contains multiple carcinogenic compounds, and ultraviolet radiation from the sun, which can lead to skin cancer. An important factor in the carcinogenic process is dose-dependence, meaning that the level of exposure to a carcinogen influences the likelihood of cancer development. Additionally, certain lifestyles, such as poor diet and physical inactivity, can increase the risk of cancer, particularly for types such as breast and colon cancer.
Risk factors for cancer also include environmental factors like radon gas and unhealthy behaviors such as smoking. Smoking is a leading cause of lung cancer, which, despite not being the most prevalent cancer, results in the most cancer deaths due to the high fatality rate associated with the disease.