Development of a job exposure matrix (JEM) for former workers in capacitor manufacturing.
Nilsen-N; Waters-MA; Hein-M; Ruder-A
23rd International Symposium on Halogenated Environmental Organic Pollutants and POPs. Dioxin 2003. Vol. 64. Boston, MA: Dioxin 2003, :132-135
Polychlorinated biphenyls (PCBs) were used as a dielectric fluid in the manufacture of capacitors from the early 1930s until they were banned in the US in 1978. Capacitor manufacturing began with winding bales of foil, paper, or plastic film in a clean, dust-free room. The bales were placed in a metal capacitor box (pre-assembly), and trays of these pre-fabricated capacitors were placed in a vacuum chamber for impregnation (flood-filling) with the dielectric fluid (PCB). Excess PCB was drained after the filling-cycle, and wet capacitors were transported to a sealing station where ports were soldered shut. Large capacitors, requiring several gallons of dielectric fluid, were filled manually through ports on the top of the capacitor and then loaded into an oven. Finally, the capacitors were degreased, leak tested, and painted. Commercial PCB brands were mixtures, using about 100 to 150 of the 209 possible congeners. The potential for adverse human health effects from PCB exposure has been examined in epidemiological studies but the results are inconsistent. One potential explanation is the lack of detailed exposure assessments. A job exposure matrix (JEM) categorizes groups of workers who share common exposures and accounts for differences in exposure across jobs. The carcinogenicity of PCBs is being investigated in several National Institute for Occupational Safety and Health (NIOSH) cohort studies. The purpose of this work was to develop a period-specific JEM for a cohort of capacitor manufacturing workers (n=3600) who worked with PCBs from 1957 until 1977.
Biphenyls; Polychlorinated-biphenyls; Epidemiology; Statistical-analysis; Mortality-rates; Mortality-data; Cancer
National Institute for Occupational Safety and Health, 4676 Columbia Parkway, R-14, Cincinnati, OH, 45226
23rd International Symposium on Halogenated Environmental Organic Pollutants and POPs. Dioxin 2003