The U.S. military prepared for the possibility that Iraq might use two
BW agents-anthrax and botulinum toxin-against U.S. service members during the
Gulf War. After the war, new data revealed Iraq had also weaponized aflatoxin.
The Committee evaluated the potential health effects of these three BW agents
on the long-term health of Gulf War veterans.
Anthrax is a bacterial disease most often found in cattle and
sheep. Human infection can occur by contact with infected animals or by
inhalation of spores from infected animal products (e.g., as hides or wool).
Left untreated the disease usually is fatal. After exposure, the anthrax
bacteria travel to the intestines and other areas where they cause severe
tissue damage. Initial symptoms include nonspecific malaise, low grade fever,
and nonproductive cough. Initially, anthrax can be difficult to diagnose
because symptoms, although severe, are not specific.103 As the
disease progresses, symptoms include high fever, labored breathing, choking
cough, and vomiting; death usually occurs within four days.276 Terminal
symptoms include abrupt onset of shortness of breath, harsh breathing, skin
turning blue, excessively rapid heartbeat, and rapid progression to shock and
death. Cases of pulmonary anthrax caused by inhalation of aerosolized
spores (which would be the case in a military use) are almost invariably fatal
if not treated immediately with antibiotics. Exposure to small numbers of
infecting spores can increase the incubation time of the disease from a few
days to several weeks, but if infection occurs, the disease progresses toward
death in the same manner as for high-level exposure.103,276 No long-term
effects have been reported in persons successfully treated for anthrax.
Botulinum toxin is a group of related, highly poisonous
protein agents isolated from fermentation of the bacterium Clostridium
botulinum, which naturally occurs in soil and can grow in many meats and
vegetables. Botulinum toxin is fast-acting, usually producing symptoms within
18 to 36 hours after ingestion. Death occurs in 80 percent of an exposed
population after one to three days.276 Botulinum toxin blocks neuromuscular
conduction by binding to receptor sites on motor nerve terminals and by
inhibiting the release of acetylcholine. Symptoms at high exposure levels can
include respiratory distress and respiratory paralysis,
which may persist for six to eight months.117 Disability progresses from
difficulty in walking and swallowing and impaired vision and speech to
convulsions. Ultimately, symptoms include paralysis of the respiratory muscles,
suffocation, and death-all within a few hours or days, depending on the amount
of toxin ingested.276 In cases of accidental exposure in the general
population, the fatality rate is 35 to 65 percent and is fatal in three to ten
days.117 Botulism antitoxin can be effective if administered within days of
exposure.276 The Committee found no scientific literature suggesting adverse
long-term health effects from low-level exposure to botulinum toxin.
In fact, botulinum toxin has conventional medical therapeutic uses. Botox®
is an FDA-approved, purified, type A botulinum toxin, and injecting it into the
muscle of patients causes a localized, temporary denervation and muscle
paralysis. Such an effect is therapeutically useful for treating a number of
conditions, including blepharospasm (an involuntary recurrent spasm of both
eyelids) and for use in certain types of eye surgery. Studies on thousands
of adults treated with Botox® have shown only mild side effects-e.g., a
diffuse skin rash lasting several days-as a result of the localized muscle
paralysis effects of the toxin. The only long-term effect reported is a slight
reduction in the effectiveness of Botox® due to a person's natural immune
Aflatoxin is a naturally occurring toxic metabolite from certain
fungi that sometimes occur on grains, peanuts, and other foods stored under
certain conditions.117 Aflatoxin ingestion can result in immediate, toxic
effects in many different species, and death results from acute liver
toxicity.29,117 Aflatoxicosis in humans has been reported following ingestion
of aflatoxin contaminated food, and symptoms include vomiting, abdominal pain,
pulmonary edema, gastrointestinal hemorrhage, convulsions, coma, and death.29
Several epidemiologic studies suggest aflatoxin causes liver cancer in humans.
The only documented health effect that could be
expected from low-level exposure to aflatoxin would be an increased
prevalence of liver cancer years to decades after exposure.
What do we conclude about the risks of BW agents to Gulf War veterans?
In cases where an individual survives exposure to anthrax or botulinum toxin,
no known, long-term health consequences exist. The Committee concludes it is
unlikely the health effects reported today by Gulf War veterans are the result
of exposures to BW agents. Aflatoxin, however, is a liver carcinogen, and
increased rates of liver cancer could result decades following low-level
exposure, although available evidence reviewed by the Committee does not
indicate such exposures occurred during the Gulf War.
join the discussion .
analyzing the major theories .
five interviews .
the veterans .
a closer look .
examining the media's role .
a guide to the site .
comparing gulf veterans' health with other veterans .
tapes & transcripts .
web site copyright 1995-2013 WGBH educational foundation