Mortality and cancer incidence among sawmill workers exposed to chlorophenate wood preservatives

Objectives. This study examined the association between exposure to chlorophenates and the risk of soft tissue sarcoma; non-Hodgkin's lymphoma; Hodgkin's disease; and cancers of the lung, nose,and nasopharynx. Methods. A retrospective cohort study was conducted of 26 487 workers employed for at least 1 year between 1950 and 1985 in 11 chlorophenate-using and 3 non-using sawmills in British Columbia, Canada. Exposures by job were ascertained with interviews of senior employees. Results. Probabilistic record linkage to the Canadian Mortality Data Base and the British Columbia Cancer Registry found 4710 deaths between 1950 and 1990, and 1547 incident cases of cancer between 1969 and 1989. None of the cancers of interest had elevated mortality related to chlorophenate exposure. Non-Hodgkin's lymphoma incidence (n = 65) increased with increasing chlorophenate exposure hours, yielding the following standardized incidence ratios: less than 120 hours 0.68; 120 to 1999 hours, 0.59; 2000 to 3999 hours, 1.04; 4000 to 9999 hours, 1.02; and 10 000 or more hours, 1.30. Conclusions. These results rue consistent with the borderline positive associations seen in other recently reported studies of chlorophenate-exposed workforces.