Colin R, et al. - The relationship between occupational exposure to metalworking fluids (MWFs) was evaluated in the steel-producing industry and bladder cancer incidence. Among workers exposed to straight MWFs and to a lesser extent to soluble MWFs, the increased risk of bladder cancer could be explained by the presence of carcinogens (such as polycyclic aromatic hydrocarbons) in mineral oils component of straight and soluble oils. Therefore, prevention remained necessary in sectors using MWFs.