Viruses Added to Cancer-Causing Agents List for the First Time

The National Institute of Environmental Health Sciences (NIEHS) and the National Toxicology Program recently issued its biennial list of known or suspected cancer-causing agents. In addition to chemicals and radiation added to this year's list, the NIEHS included the hepatitis B and hepatitis C viruses, marking the first time viruses have been added to the report.

Almost 3 million Americans are chronically infected with hepatitis C; just over 1 million are chronically infected with hepatitis B. Although there is no vaccine for hepatitis C, there is a safe and effective vaccine available to prevent hepatitis B.

Some human papillomaviruses (HPVs), which are sexually transmitted, also were included because studies have shown that they cause cervical cancer in women. Other additions to the list include lead and lead compounds, X-rays, compounds found in grilled meats, and chemicals found in textile dyes, paints and inks.

The Report on Carcinogens (11th edition), known as the "RoC," divides cancer-causing agents in two categories -- "known to be human carcinogens" and "reasonably anticipated to be human carcinogens." The RoC now lists 58 "known" and 188 "reasonably anticipated" listings. The full report can be viewed at

http://ntp.niehs.nih.gov.