Childhood cancer in the offspring of male sawmill workers occupationally exposed to chlorophenate fungicides

The objective of this study was to determine whether paternal occupational exposure to chlorophenol fungicides and their dioxin contaminants is associ ated with childhood cancer in the offspring of sawmill workers. We used dat a from 23,829 British Columbian sawmill workers employed for at least 1 con tinuous year between 1950 and 1985 in 11 sawmills that used chlorophenates. Probabilistic linkage of the sawmill worker cohort to the provincial marri age and birth files produced an offspring cohort of 19,674 children born at least 1 year after the initiation of employment in the period 1952-1988. W e then linked the offspring cohort to the British Columbia Cancer Registry. We included all malignancies in cases younger than 20 years of age that ap peared on the cancer registry between 1969 and 1993. We calculated standard ized incidence ratios (SIRs) using the British Columbia population as a ref erence. A nested case-control analysis assessed the effects of paternal cum ulative exposure and windows of exposure on the risk of developing cancer i n the offspring. We identified 40 cases of cancer during 259,919 person-yea rs of follow-up. The all-cancer SIR was 1.0 [95% confidence interval (CI), 0.7-1.4]; the SIR for leukemia was 1.0 (CI, 0.5-1.8); and the SIR for brain cancer was 1.3 (CI, 0.6-2.5). The nested case-control analysis showed slig htly increased risks in the highest categories of chlorophenol exposure, al though none was staristically significant. Our analyses provide little evid ence to support a relationship between the risk of childhood cancer and pat ernal occupational exposure to chlorophenate Fungicides in British Columbia n sawmills.