Employees at a U.S. postal facility that processed anthrax-laced letters told researchers they failed to get adequate information during the 2001 attacks, several comparing themselves to blacks who were denied treatment during the government's notorious Tuskegee experiments.

A Rand Corp. study released Tuesday found public health officials gave "very little useful information" to employees at the Brentwood (search) postal facility in Washington and to U.S. Senate staff members who might have been exposed to anthrax (search) spores.

Senate staffers reported they got reliable information from Capitol physicians, but at least some Brentwood workers said they believed government officials were more interested in observing the effects of the anthrax exposure than in treating them.

"I made it plain that I thought it was a cover-up," said one unnamed Brentwood employee who participated in the Rand study. "Because the government's done it before. They did it with syphilis."

Government researchers withheld syphilis treatment from 399 black study participants in the Tuskegee experiments of the 1930s, and there were 128 related deaths.

Two Brentwood employees died of anthrax exposure after the postal facility processed a letter containing anthrax spores on Oct. 12, 2001, that was mailed to former Senate Democratic Leader Tom Daschle. Two more were treated for inhaled anthrax, and an estimated 2,740 others were prescribed antibiotics.

Senate staffers were tested and treated beginning on Oct. 15 - the day the Daschle letter was opened. The Brentwood employees were not screened or treated until Oct. 21, after co-workers tested positive for anthrax, the Rand report found.

U.S. Postal Service spokesman Gerry McKiernan said the agency itself was not aware of anthrax exposure at the Brentwood facility until Oct. 21, and noted that Postmaster General John E. Potter (search) attended a press briefing there three days earlier.

"It's unfortunate and regrettable that some employees might still hold those views," McKiernan said. "At the time of the occurrence, very little was known about anthrax. And we were acting based on advice given to us by public health officials."

A spokesman for the Centers for Disease Control and Prevention, Llelwyn Grant said, "There was no preference shown" in informing and treating any of the estimated 10,000 people nationwide who received antibiotics during the October 2001 attacks.

The Rand focus groups were small and conducted 14 to 16 months after the attack. The study noted that the focus groups were comprised of volunteers, and not selected by random, meaning that people "more likely to have strong opinions about the events may have been more likely to participate."

Of the 36 Brentwood workers who participated in the study, 97 percent identified themselves as African-American. Five of the seven Senate staffers were white.