Why do railroad workers develop cancer?

Many jobs or crafts at the railroad have involved exposure to carcinogens such as diesel exhaust from train engines or track machines; asbestos from insulation, brakeshoes or gaskets, creosote from railroad ties; silica from ballast dust, sanders and sand blasting; welding fumes and various solvents. Over time, repeated exposure to these toxic substances can cause cancer. Many railroad workers spent decades working with and around these substances. A major cancer research center has noted the prevalence of cancer in railroad workers, due to their workplace exposures.