부산대학교 도서관

Background In early June 1998, the media uncovered a serious contamination of underground water due to improper disposal of chlorinated hydrocarbon solvents from an electronics factory. The purpose of this paper was to elucidate the background information and the environmental exposure data of the index factory as well as to show how the cohorts of the exposed group and the comparison group were established in the aftermath of the event. Methods A retrospective cohort epidemiological study was hampered by rejection of cooperation of the management of the electronics factory. The environmental exposure data were retrieved from the records of company registration, periodical industrial inspections, and chemical import information from several governmental departments. The exposed and comparison worker cohorts were constructed by tracing them back through the insurance records from the Bureau of Labor Insurance (BLI), which included computerized datasets and paper manuscripts. The records of all workers who had been employed and registered in the BLI were retrieved. Results The solvents most frequently detected and with high concentrations were tetrachloroethylene (PCE), trichloroethylene (TCE) and vinyl chloride (VC). The average concentration of PCE and TCE were about 10 times higher than the groundwater quality standard. However PCE was not used as solvent in this index factory until 1981. TCE had never been used as solvent in this factory. The numbers of cohorts were 86 868, 11 178, 14 418, and 17 960, respectively, in the exposed group, textile industry comparison group A, B and electronic industry comparison group C. Females were predominant in all of the factories. Conclusion This study was the first trial in Taiwan to establish the worker cohort and to carry out a retrospective cohort study several years after the offending company had shutdown.