A 2016 study on American firefighters from 1950 to 2010 showed that cancer is the leading cause of death among firefighters. It followed the cases of more than 30,000 firefighters in San Francisco, Chicago, and Philadelphia. Researchers found that firefighters have a higher risk of developing cancer and, compared to the general population, have a higher rate of cancer-related deaths. Firefighters are exposed to toxic soot and gases regularly. Regular exposure contributes to developing cancers such as leukemia, myeloma, and non-Hodgkin’s lymphoma. Failure to properly wash dirty equipment, protective gear, and uniforms also increase cancer risk—carcinogenic soot clings to surfaces, which can be inhaled and transferred onto the skin. The second most common leading cause of death for firefighters is heart disease. Heart disease accounts for 18% of deaths, compared to cancer-related deaths of, 61%.