Occupational Bladder Cancer in a 4,4´-Methylenebis(2-chloroaniline) (MBOCA)-Exposed Worker Chiu-Shong Liu,1 Saou-Hsing Liou,2,3 Ching-Hui Loh,4 Yi-Chun Yu,5 Shi-Nian Uang,5 Tung-Sheng Shih,5 and Hong-I Chen6 1Department of Family Medicine, China Medical University, Taichung, Taiwan, Republic of China; 2Department of Public Health, National Defense Medical Center, Nei-Hu, Taipei, Taiwan, Republic of China; 3Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Kaohsiung, Taiwan, Republic of China; 4Department of Family Medicine and Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Nei-Hu, Taipei, Taiwan, Republic of China; 5Institute of Occupational Safety and Health, Council of Labor Affairs, Shi-Jr, Taipei, Taiwan, Republic of China; 6Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Nei-Hu, Taipei, Taiwan, Republic of China Abstract A 52-year-old male chemical worker was admitted to the hospital with a history of paroxysmal microscopic hematuria for about 2 years and nocturia with gross hematuria about five times per night for 2 months. He was a nonsmoker and denied a history of any other bladder carcinogen exposure except for occasional pesticide application during agricultural work. Intravenous urogram imaging showed a mass occupying half of the bladder capacity. Cystoscopy revealed a mass over the left dome of the bladder. Cystoscopic biopsy revealed a grade 3 invasive transitional cell carcinoma with marked necrosis. From 1987 until hospital admission in 2001, the patient had worked in a company that produced the 4,4´-methylenebis(2-chloroaniline) (MBOCA) curing agent. He did not wear any personal protective equipment during work. Ambient air MBOCA levels in the purification process area (0.23-0.41 mg/m3) exceeded the U.S. Occupational Safety and Health Administration's permissible exposure level. Urinary MBOCA levels (267.9-15701.1 µg/g creatinine) far exceeded the California Occupational Safety and Health Administration's reference value of 100 µg/L. This patient worked in the purification process with occupational exposure to MBOCA for 14 years. According to the environmental and biologic monitoring data and latency period, and excluding other potential bladder carcinogen exposure, this worker was diagnosed as having occupational bladder cancer due to high exposure to MBOCA through inhalation or dermal absorption in the purification area. This case finding supports that MBOCA is a potential human carcinogen. Safe use of skin-protective equipment and respirators is required to prevent workers from MBOCA exposure. Key words: bladder cancer, MBOCA, transitional cell carcinoma. Environ Health Perspect 113: 771-774 (2005) . doi:10.1289/ehp.7666 available via http://dx.doi.org/ [Online 25 February 2005] Address correspondence to H.-I. Chen, Division of Urology, Department of Surgery, Tri-Service General Hospital, 325 Chen-Kung Rd., Section 2, Nei-Hu, Taipei, 114 Taiwan ROC. Telephone: 886-2-8792-3100. Fax: 886-2-87924814. E-mail: hong_i@ndmctsgh.edu.tw This study was supported in part by the Taiwan National Health Research Institutes (NHRI-92A1-EOPP12-1) . The authors declare they have no competing financial interests. Received 18 October 2004 ; accepted 24 February 2005. The full version of this article is available for free in HTML or PDF formats. |