Biological agents are organisms or toxins that have illness-producing effects on people, livestock and crops. Because biological agents cannot necessarily be detected and may take time to grow and cause a disease, it is almost impossible to know that a biological attack has occurred. If government officials become aware of a biological attack through an informant or warning by terrorists, they would most likely instruct citizens to either seek shelter where they are and seal the premises or evacuate immediately. A person affected by a biological agent requires the immediate attention of professional medical personnel. Some agents are contagious, and victims may need to be quarantined. Also, some medical facilities may not receive victims for fear of contaminating the hospital population.

Chemical agents can also be used as weapons, and they have been since World War I. They are compounds that cause damaging or lethal effects on humans, animals and even plants. They include incendiaries, poison gases, herbicides and other types of chemical substances that can kill, maim or temporarily incapacitate. Chemical agents can be dispersed as liquids, vapors, gases and aerosols that attack the body's nerves, blood, skin or lungs.

Medical, public health workers, and emergency personnel will work together to do the following:

• Detect disease or chemical agent
• Treat victims and those that may have been exposed
• Inform and educate the public
• Quickly respond to any additional attacks