Last week, the Food and Drug Administration announced its intention to ban blood donations from anyone who has spent a cumulative six months or more in the United Kingdom since 1980. The agency fears that blood recipients in America might contract the deadly brain infection known as Creutzfeldt-Jacob disease (CJD) -- a new variant of which has been associated with Britain's mad-cow disease, or spongiform encephalitis.

Medical experts charge the FDA did a poor job of risk assessment in adopting the policy.

• The annual incidence of CJD is one in a million -- half the risk of being struck by lightning.

• U.S. blood banks are already dangerously low on supplies, and demand for blood could outpace supply as early as next year.

• The FDA admits that there is no evidence the new variant of CJD has been transmitted by blood transfusions.

• The chief medical officer of the American Red Cross -- which collects half the U.S. blood supply -- says the FDA decision was based on "very scanty scientific data" and confirms that there has "never been a case world-wide of this disease or any related disease being transmitted by blood transfusion."

While it is estimated that the agency's ban would only result in a 2.2 percent reduction in the nation's blood supply, that loss could have a substantial impact on the number of people who need transfusions. That, in itself, is a safety issue, experts warn.

Source: Editorial, "Mad Regulatory Disease," Wall Street Journal, August 25, 1999.