Carcinogen
Introduction Cancer is a group of diseases characterized by abnormal cell growth that can invade or spread to other parts of the body. These are in contrast to benign tumours, which do not spread. A carcinogen can be defined as a substance or an exposure that has the potential to cause cancer. Several national and international agencies review available scientific evidence to assess the cancer-causing potential of various substances. International Agency for Research on Cancer (IARC) The IARC , established in 1965, is part of the World Health Organization (WHO). Since 1971, more than 1000 agents have been evaluated , of which more than500 have been identified as carcinogenic, probably carcinogenic or possibly carcinogenic to humans. The Working Group classifies an agent into one of four categories. Group 1: Carcinogenic to humans Group 2A: Probably carcinogenic to humans Group 2B: Possibly carcinogenic to humans Group 3: Not classifiable as to its carcinogenicity in humans The classifi...