Dr. James Hadler, director of infectious diseases at the Connecticut Department of Public Health top, told lawmakers that he had seen no need to inform workers of contamination because the department had determined the threat posed by anthrax was minimal. He said evidence indicated that the anthrax spores had been present for a month, during which time no postal employee had gotten sick.

Under intense questioning that followed his official statement, Hadler acknowledged that regardless of the threat level, the public and the postal employees did have a right to know about the test results but he blamed the Postal Service for not releasing the information.

But members of the Government Reform Subcommittee on National Security, Emerging Threats and International Relations were unmoved, telling Hadler that the ultimate responsibility lay with him and his department.

“The public had a right to know exactly what you found,” Rep. Christopher Shays, the subcommittee chairman, said.

Other experts who testified said Connecticut officials were unwise in allowing the postal facility to continue operating. “The conservative thing would have been to close the facility,” said Dr. Robert G. Hamilton, a professor of pathology at Johns Hopkins University School of Medicine.

Rep. Rosa L. DeLauro, who attended the hearing, called the handling of the test results “a shell game,” expressing outrage that no one ever informed her of the level of contamination during the many conversations she had with department officials in 2001.

While the testimony from civilian and military experts at Monday’s hearing revealed substantial uncertainty about what is considered “a lethal dose” of anthrax, there was widespread agreement that the amount found in one Wallingford machine – about 3 million spores, according to Hadler’s testimony – was large.

The information released after the testing in 2001, however, said only “trace amounts” of anthrax had been found.

The Centers for Disease Control discovered anthrax at the Wallingford facility after the death of 94-year-old Connecticut resident Otillie Lundgren in November of 2001. Initial tests ordered by the Postal Service had not detected any anthrax.

Hadler insisted that sufficient safety measures had been taken. Postal workers were told to take antibiotics, the cleaning of machines with compressed air – which could make anthrax spores airborne and dangerous – was suspended, and the contaminated machines were roped off.

But committee members said those measures were not enough, since anthrax spores can remain viable for years, and since some postal workers, having been told the threat was minor, chose not to take antibiotics.

“The [Postal Service] and their government failed miserably,” American Postal Workers Union President William Burrus told the subcommittee, saying that Wallingford employees had been denied the right to make informed choices about their health and safety.

The day’s testimony indicated that a large number of state and federal agencies were involved in responding to the anthrax attacks but communication between them was poor.