Cancer of the urinary bladder in highly exposed workers in the production of dinitrotoluenes: a case report

Technical dinitrotoluene (consisting of 2,4- and 2,6-dinitrotoluene isomers) has been widely used as explosives. Both technical isomers are mutagenic in Salmonella typhimurium TA98 strains and carcinogenic in rodents. 2,4-dinitrotoluene shows a dose-dependency of malignant tumors of the kidneys, liver, and mammary glands in rats and mice. In this case report, we discuss a cluster of three cases of urothelial cancer amongst a group of about 60 workers exposed to dinitrotoluenes. The workers were employed in the manufacturing of nitrotoluene explosives in the former German Democratic Republic. The cases occurred within a period of 12 years (1990–2002) leading to a 15.9 fold higher incidence of cancer of the urinary bladder than of the federal state where the chemical factory was located. The observation of the cluster of urothelial cancer in persons highly exposed to nitrotoluenes underlines the putative human carcinogenicity of dinitrotoluenes with the human urothelium as a relevant target tissue.