Post office not likely to spread anthrax spores

By Lauran Neergaard
The Associated Press

WASHINGTON “”mdash; It’s highly unlikely that any anthrax
present in a Washington post office could have contaminated other
letters awaiting delivery to people’s homes, anthrax
specialists said Monday.

“Your mail could not hold onto enough spores in the
process of making it from the postal processing area to your
home,” explained bioterrorism expert Bruce Clements of St.
Louis University. “I don’t think people need to be
concerned about receiving their mail at home.”

The Centers for Disease Control and Prevention echoed that a
risk to people at home is unlikely, noting it takes a high dose of
anthrax bacteria to become ill.

“We can’t say there’s absolutely no
risk,” CDC spokesman Tom Skinner acknowledged. But,
“based on what we know now the risk is probably small. …
Therefore our advice about handling suspected packages would still
stand.”

Health officials announced Monday that the bacteria somehow
circulated through a Washington postal facility, sickening at least
two workers with the deadly inhalation form of anthrax and possibly
killing two others.

Two men in Florida, one of whom died, have also been diagnosed
in the past 2 1/2 weeks with inhalation anthrax, a disease not seen
in this country since 1978. Six others, including two postal
workers in New Jersey, have been infected with a highly treatable
form of anthrax that is contracted through the skin.

The Washington postal facility processed the anthrax-containing
letter received by Senate Majority Leader Tom Daschle last week,
but that letter was sealed. Doctors agree a person must inhale at
least 8,000 spores deep into the lungs to contract inhalation
anthrax.

How the postal workers could have breathed in that much remains
a mystery that has bioterrorism experts like Clements puzzled
“”mdash; as well as the CDC.

“We do not have a theory,” said CDC Deputy Director
David Fleming. Because only trace amounts of anthrax were found in
post offices in New Jersey and Florida, the inhalation risk in
Washington “was not something that we expected or even in
retrospect could have anticipated,” he said.

One possibility is that the postal system cleans its equipment
with air hoses. “We blow out dust from our machines,”
said Postmaster General John E. Potter. “We are revising
those procedures as we speak.”

But once anthrax spores are in the air, studies have proved they
settle to the ground fairly quickly, within hours.

U.S. Army studies cited in the Journal of the American Medical
Association show that once settling occurs, it is very difficult
for enough spores to be blown back into the air to sicken anyone,
noted Dr. Luciana Borio of Johns Hopkins University’s Center
for Civilian Biodefense.

One such study found no significant health risk even if 1
million anthrax spores were deposited into 11 square feet and
dust-blowing helicopters landed nearby.

If someone receives a letter containing anthrax-laced powder,
“it is possible for a spore to escape an envelope,”
Surgeon General David Satcher said Monday, noting that the spores
are microscopic. “We’ve had people infected without the
envelope being opened.”

But there have to be enough spores in that one spot for that to
happen.

“I would not personally be worried about handling my
mail,” Borio stressed.

However, she noted that since bioterrorism-through-mail
hasn’t happened before, it can’t be said with certainty
that there’s no risk. “Hopefully over the next week or
so, nobody gets sick” outside of the post office and
“that will be the best evidence,” she said.

If you get a suspicious letter at home, put it down, wash your
hands with hot water and soap and call the police, Health and Human
Services Secretary Tommy Thompson advised.

The U.S. Postal Service on Monday began mailing all households a
postcard saying what should make you suspicious about a piece of
mail and what to do with it.