WASHINGTON – If you’re planning to buy a gas mask, as
many nervous New Yorkers already have, you might want
to save your money.

Despite media noise, the chances of terrorists
attacking America with biological weapons are slim,
say leading biowarfare experts. And even if terrorists
do try to spread lethal microbial agents here, they’ll
likely fail.

What if they succeed? Well, a mask won’t do you much
good anyway – not unless you wear it all the time.

Experts say it’s hard to effectively “weaponize”
deadly bugs such as anthrax – which is not
contagious, as many assume. It’s even harder to
produce large casualties, given the weather and other
factors.

“It’s not that easy to release biological agents so
that they are infective, so that they can be inhaled,”
said Dean A. Wilkening, a physicist who heads a
working group on biological terrorism at Stanford
University’s Center for International Security and
Cooperation.

Wilkening, former director of the National Defense
Research Institute, explains that terrorists have to
find a way to disperse live bugs in a wide plume, and
at the same time keep them alive. Blowing up a vat of
anthrax, for example, will more than likely kill the
bugs.

“It’s harder to make these things work than is
commonly assumed,” he said in an interview with
WorldNetDaily. “And many scenarios that are currently
being discussed probably would not work.”

What about spraying the bugs in the air?

Mohamed Atta, the late ringleader of the 9-11 attacks,
reportedly looked into chartering crop-duster planes,
leading some officials to believe Islamic terrorist
cells may have plotted to use the planes to spray
cities with deadly biological agents.

But experts say the spray nozzle on a crop duster
wouldn’t likely work as an effective respirable
aerosol, because it takes a very fine mist to infect
people with such spores.

And terrorists have had no luck using other spray
devices.

Consider Japan’s Aum Shinrikyo cult, for one.

On eight separate occasions between 1990 and 1993, Aum
Shinrikyo tried to spray anthrax and botulinum toxins
from trucks and rooftops in Tokyo, and each time it
failed. No one was infected, or at least no one died.

Main reason: The terrorists had problems developing
effective spray nozzles for aerosolizing the agents in
the 1 to 5 micron range necessary for them to lodge in
the lungs. One micron, at 0.00003937 of an inch (that’s four
zeros after the decimal point), is very, very tiny.
Aircraft fluid systems, for comparison, use 100 micron
filters.

The Iraqis, who manufactured relatively large batches
of anthrax and botulinum toxin, also had trouble
developing efficient spray nozzles, settling instead
on explosive release.

They had a program to add a payload of wet anthrax or
botulinum toxin slurry to the warheads of their
Al-Hussayn, or “Scud,” missiles. But after the Gulf
War, U.N. inspectors found their biowarfare production
facility and blew it up with demolition explosives.

The lethality of such airborne attacks depends largely
on the size of the particle dispersed, Wilkening
notes.

Particles in the 1 to 5 micron diameter deposit
efficiently in the lungs, while submicron particles
tend to be exhaled. Particles above 5 microns tend to
become trapped in the upper respiratory tract, where
higher doses are required to start an infection. Those
above 20 microns in diameter tend to settle to the
ground quickly and, as a result, do not travel far
downwind.

Of course, such hurdles don’t mean terrorists couldn’t
overcome them. If so, the results could be far more
devastating than the World Trade Center attack.

Pray for rain

A biological strike on Los Angeles or New York using
efficient devices spraying several tens of
kilograms of anthrax, for example, could result in up
to 100,000 fatalities, experts figure. If the attack
is targeted, say, on the busiest streets of Manhattan
– at lunchtime, on a clear day, with a temperature
inversion trapping agents close to the ground –
deaths could be in the millions, which is about what
you’d expect from a nuclear bomb.

Thankfully, weather is another thing terrorists have
going against them.

While anthrax spores are resistant to heat and
dryness, they’re no match for rain. A downpour would
wash most of them out of the air, where they’d become
relatively harmless.

Also, humidity and ultraviolet light decay the bugs.
So does oxygen. Anthrax and botulinum spores multiply
in the absence of oxygen.

Besides the weather, terrorists bent on mass killings
also would have to make sure deadly clouds catch
people outdoors.

If you’re in a environmentally controlled office
building with sealed windows, the integrated dose of
toxins you’d receive from a cloud passing over your
building would be reduced by a factor of 10 or more,
estimates bioterror expert Lester L. Yuan.

The higher the quality of air filters in the heating,
ventilation and cooling system, the less the exposure.
The best filter for screening out such lethal spores
is a medical filter known as a “HEPA” filter, experts
say.

If you’re in your house with the doors and windows
closed, your in-take would be cut by a factor of two
or more, Yuan says.

What about dumping bugs in the water supply?

The terrorists reportedly showed an interest in trucks
that haul hazardous waste, leading cities to tighten
security at reservoirs.

Passing on reservoirs

Anthrax bugs can also be delivered in the form of
liquid slurries. Gastrointestinal anthrax is rapidly
fatal in many cases.

But experts say reservoirs aren’t an attractive target
for terrorists, because they’d have to dump large
amounts of biological agents to overcome dilution.
Also, water supplies are filtered and chlorinated to
kill naturally occurring microorganisms, which would
neutralize anthrax and other bacteria.

“These threats tend to lack credibility,” Wilkening
said.

In fact, terrorist contamination of water supplies is
extremely rare, according to a study of such cases by
Jessica E. Stern, author of “Would Terrorists Turn to
Poison?”

Those still worried may want to buy purified bottled
water.

For these reasons, biowarfare is not a popular method
of attack by terrorists.

Aum Shinrikyo is the only example of a terrorist group
using biological or chemical weapons for mass murder.
The cult ended up turning to sarin gas to attack Tokyo
subway commuters, killing 12 and hospitalizing about
1,000.

In fact, threats or actual use of chemical or
biological weapons account for only 52 cases out of
more than 8,000 in the RAND Chronology of
International Terrorism since 1968.

Many are just scares. Wilkening counts more than 120
anthrax hoaxes alone which have been reported in the
media nationwide since October 1998.

“Except now” with the boldly brutal al-Qaida cell,
Wilkening cautioned, “we have a group that
demonstrated that they’re willing to commit mass
murder with no clear political objectives.”

Livestock cover story

In fact, Defense Secretary Donald Rumsfeld and other
administration officials recently have said that the
threat of a biological attack is quite real (although
some speculate such warnings may also serve to head
off another political embarrassment. The U.S.
intelligence community was blind-sided by the jetliner
attacks).

It’s not easy to detect biowarfare labs, since growing
the bugs doesn’t require big facilities. Iraq had a
modest-sized production facility, which escaped U.S.
notice and targeting during the 1991 war.

Export control of equipment is also tough. Fermenters
widely used for medical research can also be used to
grow lethal microbial cells and viruses. States can
say they want such vats for vaccine production or
agricultural purposes. China got such equipment
through President Clinton’s fund-raiser pal Yah Lin
“Charlie” Trie, for one. Trie, convicted of
fund-raising violations, told the FBI that scientists
there wanted it for a vaccination program. Iraq got
equipment by saying it was making single-cell protein
for livestock feed.

Some officials say bin Laden could have a lab set up
in Germany, or even here in the states.

However, it’s more likely that if bin Laden has access
to bioweapons he is a beneficiary of programs
sponsored by foreign governments which can provide
needed capital, equipment, facilities and scientists.

Wilkening says a terrorist weapon, if developed, would
be small and unlikely to cause a million casualties.
He says 10,000 to 50,000 is more realistic – and only
if they’ve perfected the weaponization technology,
which is doubtful.

Anthrax and botulinum, as bacteria that multiply
rapidly and create toxins that injure the body, are
the classic biological agents.

Of the two, anthrax is potentially deadlier. Pulmonary
anthrax, caused by inhalation of anthrax spores,
causes severe lung inflammation that can be fatal in
18 to 48 hours if untreated with large amounts of
antibiotics.

As biological agents, they are odorless, colorless,
tasteless and hard for air-quality sensors to
distinguish from other airborne biological particles
such as pollen, although new research may provide
means to detect them in the future.

Not contagious

Much of the panic now is based on an irrational fear
that anthrax and other potentially deadly bacterial
spores could spread far beyond the release zone, as
infected people travel during the incubation period
and come in contact with others.

But most toxins, including anthrax, are not
contagious.

“Anthrax doesn’t spread,” Wilkening said.

“Almost all biological warfare agents that are in the
programs of various states – the U.S. historical
program, the Russian one, the Iraqi one – are not
contagious,” he said.

Reason: On the battlefield, you don’t want them to
spread to your own troops, or your own population.

However, the small pox virus is contagious, highly so,
and it recently was brought back onto the list of
possible biological agents.

There have been revelations that the Russians, in
their covert biowarfare program, have weaponized small
pox. And there have been recent reports – one in the
Washington Times quoting unnamed intelligence sources
– that the Russian mafia may have supplied Osama bin
Laden and his terrorist al-Qaida terrorist network
with components for biological weapons.

“But we’ve had small pox outbreaks, small ones, and
they have not spread that much,” Wilkening said.
“They’ve been able to contain them.”

Millions of American adults, including baby boomers,
have been vaccinated against small pox, although the
vaccine wears off.

But some have speculated that a small pox broth
sprayed into the ventilation system of a major
international airport would, within 24 hours or so,
cause an epidemic to break out across the world,
making the virus harder to contain.

Small pox vaccine?

Rolling out a national small-pox vaccination program
to immunize every American might work as a
prophylactic against such a biological attack. But it
may not be feasible right now due to a lack of virus
stores to remanufacture the vaccine, which was phased
out some time ago.

Constant TV media coverage has whipped Americans into
a panic over a possible biowarfare attack.

Hysteria has prompted big city-dwellers to empty store
shelves of respiratory masks.

But such masks offer a false sense of security,
experts say, because people won’t know when to put
them on.

Buying antibiotics won’t help much, either, since
people won’t know which antibiotic they’ll need, or
when to take it.

Many who argue that the bioterror threat is overblown
advise Americans to stay alert, yes, but calm.

“People are very scared these days, and we don’t want
to exaggerate the likelihood or the consequences of a
possible biological attack,” Wilkening said. “But we
should still be vigilant.”

Previous stories:

FAA inspector: Airport security tests rigged

U.S. equipped terror sponsors

Captains to FAA: Focus on cockpits

Pistol-shooting parties at terrorist safe-house

Tactical nukes may be necessary

Flying United (gulp) out of Dulles (gulp)

Why the Pentagon was so vulnerable

Terrorists slit throats of 2 AA stewardesses

Flight 11 had mechanical delays last week

Lobsters, not explosives, on American jet

Pentagon suspects Osama bin Laden

Related column:

Please, Mr. Bush, no Basrah this time

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