thats why size is important for dispersal, however, the point is, they are so small you could have no idea you inhaled any. It's not like inhaling ground pepper, which you can see, more like onion juice droplets/vapor, which you cant.
The most dangerous elements of anthrax are, as we know, the inhalation strains as opposed to the cutaneous strains. What makes anthrax 'weapons grade' is it's purity and granularity. A cutaneous strain is an effective weapon in an underdeveloped country where immune systems are low and antibiotics are scarce. Additionally, U.S. weapons inspectors are quoted as having identified large quantities of both cutaneous and inhalation strains of anthrax as being cultivated and present in Iraq. They also identified modified scud warheads for use as the delivery agents believing that even if the missile is destroyed that some of the agent is likely to survive. There are also concerns that Iraqi scientists may have inadvertantly stumbled onto mutations of anthrax in their experiments and that some of the data we have on anthrax may not be 100% accurate. (For example some of it may be dually active inhereting characteristics of multiple strains) This makes it tougher to identify the weaponized anthrax available through the Iraqis.
We have not yet been hit with a large scale anthrax attack on the population at large. A devastating attack would require massive airborne coverage and sophisticated delivery devices in order to spread the inhlation strain. However, all terror is not aimed at mass homocide, sometimes it is solely intended as a disruption, and for that the current situation certainly seems to be accomplishing some goals for these parasites.
Patient vigiliance from the population and continued strong support for those in the government and those in government service (military, police, et al) are the calling of our generation, and they will be the marks of our victory.