Carcinogens play a pivotal role in the development of malignancies. They are categorized based on their origin and include chemical (e.g., tobacco smoke), physical (e.g., ultraviolet radiation), and biological (e.g., certain viruses) agents. The International Agency for Research on Cancer (IARC) classifies carcinogens into groups based on their potential to cause cancer in humans. Understanding these categories helps toxicologists assess the risk associated with different exposures.
