Updated Carcinogen List Includes Viruses, X-Rays
Officials for the HHS National Toxicology Program on Monday updated a government list of known and suspected causes of cancer to include hepatitis B and C, human papillomavirus, lead, X-rays and compounds in grilled meats, the AP/Contra Costa Times reports. Federal law requires the HHS secretary to update the Report on Carcinogens every two years. Seventeen substances were added to the list, which now contains 58 "known" and 188 "reasonably anticipated" carcinogens (Superville, AP/Contra Costa Times, 2/1).
The updated list is the 11th version of the report. According to the San Francisco Chronicle, researchers based the revisions on "thousands of studies and discussion among panels of experts." The list "is significant because government agencies use the report as a definitive guide when considering new environmental, consumer, and occupational health regulations," the Chronicle reports (Kay, San Francisco Chronicle, 2/1).
According to the AP/Times, officials "decided to go beyond the report's historical focus on the occupational and environmental causes of cancer" (AP/Contra Costa Times, 2/1). Scientists added the hepatitis B and C viruses to the list because the viruses have been known to cause liver cancer and are instigating "widespread public health problems," the Chronicle reports (San Francisco Chronicle, 2/1). In addition, some forms of the human papillomavirus were added to the list because they can increase a woman's risk of cervical cancer.
X-rays, which are known to increase the risk of cancer for children and women in their reproductive years, were added to list. Christopher Portier, associate director of the National Toxicology Program, said X-rays were added to the list "simply to remind [people] that when they are making a decision about an X-ray to think about it and talk it over with [their] physician" (AP/Contra Costa Times, 2/1). The agency stated, "X-radiation and gamma-radiation are listed in the report as 'known human carcinogens' because human studies show that exposure to these kinds of radiation causes many types of cancer, including leukemia and cancers of the thyroid, breast and lung." The agency added that a person's cancer risk because of these types of radiation "depends to some extent on age at the time of exposure." The report states that X-rays and gamma radiation also have been shown to cause cancer of the salivary glands, stomach, colon, bladder, ovaries, central nervous system and skin (Reuters, 1/31). Other suspected carcinogens added to the list include:
- Lead, such as that used to make lead-acid storage batteries, ammunition and cable coverings;
- Lead compounds, used in paint, glass, ceramics, some cosmetics and fuel; and
- Substances that form when meats are cooked or grilled at high temperatures.
Representatives of the American College of Radiology said the addition of X-rays and gamma rays to the list is misleading and could contribute to some patients' decision to avoid necessary treatment. James Borgstede, chair of the ACR board of chancellors, said, "X-rays and gamma rays are not substances that the general public has access or exposure to and do not belong on a list of substances that pose a risk to people in the course of their normal, daily lives."
Elizabeth Whelan of the American Council on Science and Health called the list "not consumer friendly" and suggested that the list include information on the types and dosages of exposures that can cause cancer.
Portier said, "We felt (the report) needed to be expanded to include other things in our general environment that can cause cancer." He added, "We think everything on this list is, in fact, relevant to people's daily lives and the public health of the country." Portier said agencies such as FDA and the Environmental Protection Agency are responsible for determining issues of exposure and dosages.
Michael Thun, director of the American Cancer Society's epidemiological program, said the addition of viruses was necessary, adding, "These are human carcinogens and very important carcinogens" (AP/Contra Costa Times, 2/1).