We have identified 71 chlorophenate-exposed sawmill workers as part of a group undergoing an extensive health and environmental evaluation in a pulp mill. We have compared this group with a group (351) with no physical proximity to the area in which chlorophenates were used. We demonstrated a gradient of exposure from 230 ppb in urine and 919 ppb in serum for those directly handling the contaminated wood, to 139 ppb in urine and 354 ppb in serum for those working in the area but not in manual contact as compared with serum levels of 84 ppb in the unexposed group. We noted that the bulk chemical was primarily in the tetrachloro-form but the serum levels contained more pentachlorophenate. The urine proportions were intermediate, approximating the bulk chemical proportions at the lower levels of exposure. We did not find an excess prevalence of respiratory symptoms or spirometric abnormalities which could be explained by the chlorophenate exposure.