Tokyo -- Japan got a wake-up call nearly a decade ago to the threat of assaults using biological weapons against civilians when a doomsday cult tried to make their prophecies of Armageddon come true by dispersing anthrax.
Even so, experts say that Japanese officials failed to learn the lessons of the botched attempt by the Aum Supreme Truth cult.
"It is impossible to totally prevent such attacks ... but you can limit the impact," said Keiichi Tsuneishi, an expert on bio-terrorism at Kanagawa University.
"But in Japan, there is no overall system to deal with this."
Experts have been warning of the possibility of chemical or biological assaults for years, but concerns have mounted since the devastating September 11 attacks in America and the U.S.-led retaliation in Afghanistan.
In Florida, an employee of a publishing company died on Friday from exposure to anthrax and two more have tested positive for exposure to the bacteria.
The probe into the infection is now being handled as a criminal investigation, U.S. officials said on Wednesday.
Japan's Aum cult made horrific history in March 1995 when its members released the deadly nerve gas sarin on crowded subways in Tokyo, killing 12 people and making nearly 6,000 ill.
What attracted rather less attention was the fact that Aum cult members had two years earlier sprayed anthrax into the air above their Tokyo headquarters.
The fact that it was a harmless strain designed to be used as a vaccine for cattle prevented a disaster from occurring, Tsuneishi said.
"There were complaints from those living nearby about a strange smell," he said. "If this had been a strain from which a bio-weapon could be made, it would have been far more serious."
But Northern Arizona University researcher, Paul Keim, who also obtained a sample, said the anthrax strain was a harmless one imported from the United States and designed for use as a vaccine for cattle, the Daily Yomiuri newspaper reported.
Anthrax has long been known as a disease of farm animals, and in its most common form -- a skin infection -- is not especially lethal.
But the bacteria that causes anthrax can form spores, which can be sprayed by something like a crop-dusting plane or released by a home-made aerosol.
Some experts have cited Aum's botched attempt as pointing to the difficulties of executing successful biological attacks.
"If Aum had taken more time and been more proficient it might have killed thousands or even tens of thousands," said an article which appeared in Jane's Intelligence Weekly in June 1999.
"In short, chemical, biological and nuclear weapons are harder for terrorists to obtain and to make than some reports would suggest," the article said.
Tsuneishi said, however, that better coordination among ministries was essential, as was raising the consciousness of researchers themselves about potential for theft by terrorists.
In a display apparently intended to demonstrate preparedness, a counter-terrorism police unit on Wednesday enacted a drill before television cameras.
The unit was set up last year and has been doubled to 20 members following last month's attacks.
Japan's military, however, has been slow to boost readiness for possible biological attacks, in part due to the legacy of the Imperial Army's top-secret Unit 731, which conducted biological experiments on Chinese, Korean and Russian prisoners of war during World War Two, analysts say.
"In general, the capacity to cope is very limited," defence expert Tomohisa Sakanaka told Reuters recently. "It has been thought that for the military even to do research on such things is itself dangerous...We have learned too much from history."