Two Offset Printing Workers with Cholangiocarcinoma

Two Offset Printing Workers with Cholangiocarcinoma: Shinji KUMAGAI. Department of Management of Occupational Safety and Health, University of Occupational and Environmental Health, Japan— Objectives Previously, the author reported a cluster of 11 cholangiocarcinoma cases exposed to 1,2‐dichloropropane (1,2‐DCP) and/or dichloromethane (DCM) in an offset proof‐printing company. Before that report, the association between the two chemicals and cholangiocarcinoma had not been known. The current study describes two cholangiocarcinoma patients exposed to 1,2‐DCP or DCM in different offset printing companies. Methods The author obtained medical records for the patients, and interviewed the surviving patient and a relative of the deceased patient about their occupational history. Results Case 1 was a man born in 1950. He worked in the printing section in a proof‐printing company for 26 years. He was diagnosed as cholangiocarcinoma in 1998 and died in 2000. In proof‐printing operations, he used gasoline for 14 years and 1,2‐DCP for 11 years to remove ink from a rubber transcription roller (blanket). The exposure concentration of 1,2‐DCP was estimated to be between 72 and 5,200 ppm. Case 2 was a man born in 1963. He worked in the printing section in a general offset printing company for 11 years. He was diagnosed with cholangiocarcinoma in 2007. In printing operations, he used both kerosene and a mixture of 50% DCM and 50% 1,1,1‐trichloroethane (1,1,1‐TCE) for 11 years to remove ink from a blanket. The exposure concentration of DCM was estimated to be between 240 and 6,100 ppm. He was simultaneously exposed to similar levels of 1,1,1‐TCE. Conclusions Because the offset printing process may cause cholangiocarcinoma, occupational history should be examined for patients with this cancer.