Environmental risk factors for liver cancer

In the 2021 Report on Carcinogens, the National Toxicology Program of the United States listed 63 known human carcinogens. While many of the listed agents are environmental factors, only 2, aflatoxin and vinyl chloride, have been definitely linked to types of liver cancer. Aflatoxin is well known to increase the risk of HCC, while vinyl chloride is a cause of angiosarcoma of the liver. A number of other environmental factors have been studied for an association with liver cancers, such as air pollution, perfluoroalkyl and polyfluoroalkyl substances, cyanobacteria, pesticides, aristolochic acid, polycyclic aromatic hydrocarbons, asbestos, arsenic, and organic solvents; however, limited evidence exists for these exposures. It is the goal of this review article to examine what is currently known about environmental risk factors and liver cancer and suggest which ones should have the highest priority for further research.