US lists cancer causes

WASHINGTON - Oestrogen replacement therapy joined the official United States Government list of cancer-causing agents yesterday, with wood dust and ultraviolet light.

A big study published in July showed that hormone replacement therapy increases the risk of several kinds of cancer, including breast cancer, although it seems to lower the risk of colon cancer. It also raises the risk of heart disease.

The report also lists wood dust as a "known human carcinogen". The report, part of the National Toxicology Programme's biennial report on cancer-causing agents, says unprotected workers in sawmills, furniture factories and similar places have a higher risk of cancers of the nasal cavities and sinuses.

And it lists broad-spectrum ultraviolet light, both naturally produced by the sun and the light made by tanning beds and lamps, as a known cause of cancer in people.

The separate kinds of UV light, such as UVA, UVB and UVC, are listed as probable carcinogens because it is not clear whether each one on its own could cause cancer.

"This and 15 other new listings bring the total of substances in the report, 'known' or 'reasonably anticipated' to pose a cancer risk, to 228. The NTP, part of the National Institute of Environmental Health Sciences, one of the National Institutes of Health, updates its list of known and suspected cancer-causing agents after scientific reviews by three panels of Government and non-Government scientists.

Also new to the list are nickel compounds and beryllium and its compounds commonly used in industry. Beryllium was previously listed as "reasonably anticipated to be a human carcinogen".

Joining the list of reasonable cancer suspects are IQ, or 2-amino-3-methylimidazo(4,5-f)quinoline, which is formed during direct cooking with high heat of foods such as meat and eggs and which is also in cigarette smoke.

- REUTERS

Herald feature: Health