Biological agents are viruses, bacteria, and fungi which have potential applications in biological warfare or bioterrorism. A wide range of infectious agents could potentially be deployed as biological agents, and several nations have conducted extensive research programs to identify such agents and develop methods of responding to biological attacks. Like nuclear weapons and chemical agents, biological agents are considered weapons of mass destruction.
Several features distinguish a biological agent from an ordinary infectious or disease-causing organism. Biological agents are often lethal, and they are highly effective, even in small amounts. They are also extremely difficult to kill, and capable of dispersing themselves widely and rapidly across a large area. They may act in a wide variety of ways. Some release toxins which kill people and animals, while others attack the body in some way, causing nervous system damage, acute hemorrhage, pulmonary problems, diarrhea, and other symptoms.
There are a number of concerns about biological agents. The first is that the release of biological organisms is very difficult to control. If a terrorist released anthrax in one country, for example, it could quickly spread to neighboring regions, or be carried even further by the jet stream. Biological agents also do not distinguish between civilians, soldiers, friends, and foes, and they can cause serious long-term damages, such as contamination of land and waterways.
Many nations have signed treaties in which they have agreed to refrain from using biological agents in warfare, and to destroy stockpiles of such agents. However, research programs on biological agents are still thriving in many nations, under the argument that people need to be prepared for the deliberate or accidental release of a biological agent. The safety and security of some programs has been questioned, especially in the wake of revelations about stolen biological material which came from labs in Russia in the late 20th century.
While the international community has agreed that the use of biological agents should be banned, terrorists have signed no such agreement, and this is a cause of great concern. Some biological agents are very easy to obtain and cultivate, with labs all over the world freely supplying biological materials for research. As a result, terrorists could easily launch an attack with biological agents in a target region of their choice. Anti-terrorism programs around the world have specific units to monitor the sales of various potentially dangerous organisms, and these programs also audit laboratory safety at legitimate labs, and perform routine screening for biological agents on people and goods which cross international borders.