Validation of a Mill-Specific Job-Exposure Matrix in the British Columbia Pulp and Paper Industry

Abstract Job-exposure matrices (JEMs) are being used to organize occupational exposure assessments for a nested case—control study of British Columbia pulp and paper workers. To validate the methodology used to create the JEMs, the estimates from the first mill studied were compared with personal measurements subsequently collected from that site. In total, 1678 samples were collected from workers to assess their exposure to five chemicals; these samples characterized both shift-long average and short-term high level exposures. The comparison indicated that the estimates were effective at predicting which job titles were exposed to carbon monoxide, calcium oxide, and wood dust, but less so for chlorine dioxide. Estimates were also effective at predicting which job titles were unexposed to calcium oxide, but less so for carbon monoxide, chlorine dioxide, and wood dust. The differing degrees of agreement between the estimates and measurements can be partly explained by the physical characteristics of each c...