In addition to environmental monitoring, the Taiwan IOSH also collected workers' urine to monitor MBOCA concentrations.
The total urine MBOCA concentrations ranged from 267.
Although the production of MBOCA in the United States ceased in 1982, MBOCA is still manufactured in other countries.
Environmental monitoring of MBOCA levels in ambient air performed in the present study showed that the concentration was high in the purification process area (0.
In addition to exposure to high air concentrations of MBOCA, workers in the patient's plant also showed high levels of MBOCA in urine.
The bladder cancer patient reported here worked in the purification process with high exposure to MBOCA for 14 years.
Limited epidemiologic studies have examined the incidence of cancer in workers exposed to MBOCA, and three cases of bladder cancer have been reported to be associated with MBOCA exposure.
This case finding supports the conclusion that MBOCA is a potential human carcinogen.