There are several different methods of dispersing biological agents to harm humans, plants, and animals- all of which involve the ingestion of the agent into the host organism or contact with the agent itself.   These dispersal methods include:







Each microorganism that serves as a potential biological weapon has unique characteristics that can make it difficult to use as a weapon, which include their affinity for sunlight or heat.  Others have to be a certain size to enter the lungs in large enough numbers to be effective. The agent  may also only affect certain especially susceptible individuals, including older adults or immunocompromised hosts. It usually takes approximately 8,000 to 10,000 1-mm to 5-mm spores of a biological agent to enter a person’s respiratory tract, however it is extremely difficult for microbes to enter the bloodstream.  Most microbes used in biological warfare attack the lymph system by generating toxins.

There still is a lot of speculation as to the real nature of biological agent microbes because they have the ability to act in unexpected ways.  This ultimately makes the solution to the problem of bioterrorism even more problamatic.