ABSTRACT
This article reviews newly available knowledge regarding occupational cancer based on an assessment of International Agency for Research on Cancer (IARC) Monograph program from 2006 to 2010. The IARC reviewed the agents to evaluate the carcinogenicity in humans according to their priority. During the last five years, the IARC has reviewed many kinds of agents, including all of the Group 1 carcinogenic agents. Agents belonging to groups other than Group 1 were also reviewed. A few agents, such as shiftwork and firefighting, were reviewed for the first time after introducing the IARC Monograph Program. Most of the reassessed Group 1 agents were reaffirmed, showing that there was sufficient evidence to prove their carcinogenicity to human beings. However, some carcinogens were correlated to the new cancer site, since it was deemed that sufficient evidence was present. For example, larynx and ovary cancer deemed to have sufficient evidence of carciongenicity relating to asbestos exposure, joining lung cancer and mesothelioma. Some agents, such as benzo(a)pyrene, ortho-toluidine, 1,3-butadiene, and others belonging to Group 2A were upgraded to Group 1 based on newly identified epidemiologic findings, along with sufficient animal and mechanistic evidence. Benzo(a)pyrene and benzidine-based dyes were classified as human carcinogens based on sufficient animal and pervasive mechanistic evidence. This new data shows that not only chemical agents but also working conditions, such as stress and shiftwork were found to apply to human carcinogenicity. The IARC listed these agents in order to prioritize their review regarding their carcinogenicity to humans. There is a great need to study these newly emerging agents suspected to relate human carcinogenicity, and deem they are worthy of notice.