It took more than three hours to reach the head of the line.

Hundreds of people queued up for anthrax tests in the United States Congress on Wednesday, such was the demand from an increasing number of people who felt they might have been at risk.

They included staff, members, visitors and journalists who had been in the Senate office building where the anthrax-infected letter sent to Senator Tom Daschel was received.

I waited with an intern who worked in a senator's office in another part of a different building to where the letter was opened.

Others in line were a lobbyist who had been in that building on Tuesday morning, as I had, and a student whose room-mates worked there.

People were calm, apprehensive, but glad they had come.

Nasal swab

The procedure consisted of a swab taken from the back of each nasal passage.

The results will be notified by the week end.

In the meantime, each person is given six days' supply of the antibiotic Cipro as a precaution.

This treatment will not be continued if the test is negative.