For the past five years, the Committee on the Biological Effects of Ionizing Radiation (BEIR VII) of the National Academy of Science has reviewed and analyzed the health risks from exposure to low levels of radiation (X-rays and gamma rays.) This re-assessment followed a period of rich accumulation of biologic and epidemiologic data from 1990 on, the year of the last previous study (BEIR V.)

The scientific evidence showed that even low doses of radiation may pose a risk of cancer, and that there was no threshold below which exposure may be viewed as harmless. Lifetime excess risks were determined for 12 relatively common cancers. While the over-all risk of cancer at low radiation levels is small, the mortality in women is higher than in men, and infants are at greater risk than adults. The presentation will review the conclusions of the 700-page report.

Herbert L. Abrams, M.D., Professor Emeritus of Radiology at Stanford, was formerly Philip H. Cook Professor and Chairman of Radiology at Harvard, and has been a CISAC Member-in-Residence since 1985. He served as one of the two physicians on the BEIR VII committee, the other members, representing radiation biology, cancer biology, physics, epidemiology and genetics. The 1st edition of his three volume work, Abrams Angiography: Vascular and Interventional Radiology, was published in 1961, the fifth edition in 2005. He is the author or co-author of six other books on Congenital Heart Disease, Coronary Arteriography, Diagnostic Decision Making, Diagnostic Technology Assessment, and Presidential Disability and of over 200 refereed papers on cardiovascular disease, health policy, disabled leadership, human instability in the nuclear forces, and inadvertent nuclear war. A member of the Institute of Medicine of the National Academy of Sciences, he was also the founding Vice-President of International Physicians for the Prevention of Nuclear War (IPPNW), recipient of the 1985 Nobel Peace Prize.

Cellular prion protein (PrPC) is present in the healthy adult brain. It is a presumably essential membrane protein but its cellular function is unclear. Like Ice-9 - the fictitious water allotrope in Kurt Vonnegut's Cat's Cradle, which "taught the atoms a novel way in which to stack, lock and crystallize until the oceans turned to ice" - cellular prion protein can, in a rare event, adopt a pathogenic and 'contagious' shape, PrPSc, which causes mad cow disease or Bovine Spongiform Encephalopathy (BSE). New variant Creutzfeldt Jakob Disease (vCJD) is the human malady attributed to eating beef tainted with BSE. In comparison to the UK epidemic (at the peak of which 37,280 cases of BSE were reported in the single year 1992), the emergence of four North American mad cows since May 2003 is minor yet still alarming. This work examines the USDA's response to indigenous BSE as manifested in "The Final Rule" (9 CFR 93-96, Jan 4, 2005) and questions whether current regulations are stringent enough to keep PrPSc out of cattle feed and human food.

Sheila Healy is a CISAC Science Fellow. She is currently analyzing USDA policy addressing Bovine Spongiform Encephalopathy (BSE) or mad cow disease. She recently finished a postdoctoral appointment in Stanley Prusiner's laboratory in the Department of Neurology at the University of California, San Francisco. There she studied the molecular and structural requirements for the conversion of cellular prion protein to its pathogenic form, the agent that causes BSE. She holds a doctoral degree in biochemistry and molecular and cellular biology from the University of Arizona.

Medical anthropologist and physician Paul Farmer has dedicated his life to treating some of the world's poorest populations, in the process helping to raise the standard of health care in underdeveloped areas of the world. Paul Farmer has worked in infectious-disease control in the Americas for nearly two decades and is a world-renowned authority on tuberculosis treatment and control. Dr. Farmer has pioneered novel, community-based treatment strategies for infectious diseases (including HIV/AIDS and multidrug-resistant tuberculosis) in resource-poor settings.

In 1993, he was awarded a John D. and Catherine T. MacArthur Foundation Genius Award in recognition of his work, and in 2003 the Heinz Award for the Human Condition.