In the line of duty, firefighters are exposed to a range of toxic chemicals, some of which are known to cause cancer. Despite the immediate dangers that accompany the occupation, cancer is the leading cause of line-of-duty deaths in firefighters. There is growing concern that long-term exposures to these chemicals at the fire scene, and during the cleaning of contaminated uniforms, gear, and stations, are contributing to these increased cancer rates. Several markers of exposure to known cancer-causing chemicals have been detected in the body fluids of firefighters.