Occupational Health Research and Development Center

Japan

Occupational Health Research and Development Center

Japan
SEARCH FILTERS
Time filter
Source Type

PubMed | Occupational Health Research and Development Center
Type: Journal Article | Journal: Journal of occupational health | Year: 2015

In several Japanese printing plants, printing workers have suffered from cholangiocarcinoma. 1,2-dichloropropane (1,2-DCP) is considered to be a causative agent, and whether or not other chemicals also contribute to the development of this disease has not been conclusively determined. This study aimed to identify the chemicals used by seven printing workers who developed cholangiocarcinoma, as well as to estimate the levels of chemical exposure among them.Information was obtained from the Ministry of Health, Labour and Welfare, Japan, to identify chemicals used by printing workers who developed cholangiocarcinoma and to estimate chemical exposure concentrations. Working environment concentrations of the chemicals in the printing rooms were estimated using a well-mixed model, and exposure concentrations during the ink removal operation were estimated using a near-field and far-field model. Shift time-weighted averages of exposure concentrations were also calculated.Four of the seven printing workers were exposed to both 1,2-DCP and dichloromethane (DCM). The estimated maximum exposure concentrations for each of the four workers were 230 to 420 ppm for 1,2-DCP and 58 to 720 ppm for DCM, and the estimated shift average exposure concentrations were 0 to 210 ppm for 1,2-DCP and 15 to 270 ppm for DCM. The remaining three workers were exposed to DCM but not 1,2-DCP. The estimated maximum exposure concentrations of DCM for each of the three workers were 600 to 1,300 ppm, and the estimated shift average exposure concentrations were 84 to 440 ppm.Our findings suggest that DCM may contribute to the development of cholangiocarcinoma in humans.


PubMed | Occupational Health Research and Development Center
Type: Case Reports | Journal: Journal of occupational health | Year: 2016

This study aimed to identify the chemicals used by five printing workers and one coating worker who developed cholangiocarcinoma and estimate the workers levels of chemical exposure.We obtained information on chemicals from the Ministry of Health, Labour and Welfare, Japan, and estimated working environment concentrations of the chemicals in printing and coating rooms and exposure concentrations during the ink and dirt removal processes. We also calculated shift time-weighted averages of exposure concentrations.All five printing workers were exposed to both 1,2-dichloropropane (1,2-DCP) and dichloromethane (DCM). The estimated maximum exposure concentrations for each of the five workers were 190 to 560 ppm for 1,2-DCP and 300 to 980 ppm for DCM, and the estimated shift average exposure concentrations were 0 to 230 ppm for 1,2-DCP and 20 to 470 ppm for DCM. The coating worker was exposed to 1,2-DCP, but not DCM. He did not use ink, and thus was subjected to different conditions than the printing workers. The estimated maximum exposure concentration of 1,2-DCP was 150 ppm, and the estimated shift time-weighted average exposure concentration was 5 to 19 ppm.Our findings support the notion that 1,2-DCP contributes to the development of cholangiocarcinoma in humans and the notion that DCM may also be a contributing factor. The finding that the coating worker was exposed to 1,2-DCP at a lower exposure concentration is important for determining the occupational exposure limit. Furthermore, the subject did not use ink, which suggests that ink did not contribute to the development of cholangiocarcinoma.

Loading Occupational Health Research and Development Center collaborators
Loading Occupational Health Research and Development Center collaborators