Officials worry over trail of anthrax through mail

Spores can possibly leak from envelope seams, bioweapons experts say

War On Terrorism

Anthrax Scare

October 23, 2001|By Scott Shane | Scott Shane,SUN STAFF

Could an unopened envelope containing anthrax powder pass through the U.S. postal system and leave a trail of deadly disease in its wake?

Experts in biological weapons, struggling to make sense of two deaths and several illnesses among workers at a Washington mail-handling facility, said yesterday that anthrax spores could probably puff from the seams of a letter during handling. Postal workers said letter-sorting requires repeated handling of letters by people and machines, some of which are cleaned with powerful jets of air.

Worried federal officials began to discuss whether mail could be routinely disinfected using ultraviolet light, irradiation or other technology. But no such process has been developed, and specialists said the government faces a major challenge to decontaminate buildings and machinery where anthrax has been found.

David R. Franz, a former top Army biodefense official, said anthrax cannot pass through intact paper. But if anthrax particles in a letter were sufficiently small, they could leak during handling, he said. "I would think it might be possible for the envelope to have a sort of bellows effect," said Franz, at the Southern Research Institute in Frederick. "Compressing the envelope could puff some spores out. ... The particle size would have to be small enough that it hangs in the air, almost like a vapor."

Franz said the estimated 8,000 to 10,000 microscopic spores necessary to infect a single person with inhalational anthrax would be too small to see, so they could float invisibly near a postal machine long enough to be inhaled by a nearby worker.

Raymond Zilinskas, a former United Nations weapons inspector, agreed, noting that ordinary envelopes have small openings at the ends of the flap even if they are well-sealed.

Zilinskas said he doubted spores clinging to the outside of an envelope could give someone inhalational anthrax, which is usually fatal. It's conceivable that such bacteria -- or even spores on mail that passed through contaminated postal machinery -- could cause the less serious, cutaneous form, he said.

Some experts called on the federal Centers for Disease Control and Prevention to release more information about the powder found in a letter sent last week to Sen. Tom Daschle and at other locations in Washington, as well as at New York and Florida.

"It would be helpful if the CDC could provide clinicians and the professional community with as much information as is available," said Dr. Tara O'Toole, deputy director of the Center for Civilian Biodefense Studies at the Johns Hopkins University. "One of the unanswered questions has to do with the nature of the powder and whether its analysis shows it could be widely aerosolized," or spread by air.

Any letter sent through the U.S. mail goes through multiple sorting stations, and each stage involves a dynamic process in which mail is constantly jostled and squeezed.

"With each sort, there are people who need to feed the machines," said Thomas Boyle, a spokesman for the U.S. Postal Inspection Service. "Then there are quality assurance people making sure everything's moving right, as well as maintenance workers and engineers, not to mention a cadre of mail handlers."

At the Brentwood facility in Washington, where the sickened workers were assigned and the Daschle letter was sorted, machines are cleaned with compressed air guns of the kind found in an auto-repair shop, said Louis Barham, 49, a letter carrier who works there. "Ever have your tires changed before? It's like that," Barham said. Though the air guns don't kick up clouds of visible dust, "common sense tells you that when they spray, stuff blows around."

To decontaminate buildings where anthrax has been found will be a major job, experts said. The Environmental Protection Agency said yesterday that it will use Superfund money to clean up at American Media Inc., the Florida tabloid publishing company where anthrax was first found and one man died. Diluted household bleach wiped on contaminated surfaces will kill anthrax, but bleach is impractical for large buildings and delicate equipment. Franz said the Army biodefense facilities at Fort Detrick are decontaminated using formaldehyde gas, but that is toxic to humans.

A new germ-killing foam, developed at Sandia National Laboratories in New Mexico, is safe for people and friendly to the environment, said Cecelia V. Williams, a chemical engineer at Sandia. Using an ingredient in hair conditioner, the foam neutralizes some chemical agents as well as killing anthrax and other bugs. "It essentially busts open the coat of the anthrax spore and kills it," she said.

Peter J. Beucher, president of EnviroFoam Technologies of Huntsville, Ala., which makes the foam, was in Washington yesterday, prepared to decontaminate congressional offices and postal buildings if asked to do so. But he acknowledged that no such product can prevent recontamination. "What's to keep whoever's doing this from doing it again?" he asked.

With that threat in mind, postal officials are studying methods to disinfect all mail, possibly like those used on food. But such a prospect is months or years away, they said. In the meantime, said Zilinskas, of the Monterey Institute, "the people sending this stuff out can close up all kinds of facilities. Our vulnerabilities are endless."

Sun staff writers Michael James and Michael Stroh contributed to this article.

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