A "dirty bomb" is a conventional explosive packaged with material designed to cause even greater damage than the explosive. Most likely, the "dirty" material will be radioactive. There are conflicting views regarding the harm that can be caused by a "dirty bomb," primarily because the threat is dependent on which radio nuclide is used, how much radioactivity is produced, and prevailing wind conditions. In case a dirty bomb does explode, first responders must be equipped with protective clothing when they enter the hot zone after an attack. Respiratory protection is crucial, because an explosion will release finely pulverized radioactive materials into the air that can easily be washed off of a uniform and the skin; however, if officers breathe in radioactive particles, they will receive long-term exposure to low levels of radiation that can cause life-long health problems. The existence of radioactive materials can be detected with appropriate radiation detection devices. Preparation for and the prevention and mitigation of a dirty bomb attack require a coordinated effort that involves partnerships with business, industry, public health, medicine, academia, and transportation sectors. These partnerships aid law enforcement agencies in learning what radiological sources exist in the area, ascertaining potential terrorist targets, and developing an effective response plan. A terrorism response group is appropriate for a single city or county, multiple counties, or a given region. Once an agency has the appropriate protection and partnerships in place, the next step is to train personnel for many different types of terrorist attacks. This type of training includes learning to use radiation detectors, self-contained breathing apparatus, and other protective gear; training with other public safety organizations; and modifying existing operating procedures based on lessons learned during the training.