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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.
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 responses.


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.


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