Several studies have been conducted to assess the exposure of a cohort of former
herbicide-producing workers to
PCDD/F and other potential carcinogenic substances and to evaluate the morbidity and mortality, especially for
cancer, but also for other causes of death. For a quantitative dose-response analyses, a
PCDD/F-blood exposure
indicator was constructed from available blood levels for n = 190 workers and its relation to the working times in 14 different production departments. These indicators were used in Cox-regression models relating total
cancer mortality to estimated TEQ at the end of exposure. A significant trend was observed for total
cancer mortality and estimated TEQ levels at the end of exposure. The form of the dose response curve appeared to be slightly sublinear in the observed dose range. For all
cardiovascular diseases (CVD), a numerical increase in risk was first observed in the third quintile of the exposure
indicator 39.6-98.9 ng/kg; (RR 1.20; 0.82, 1.76), increasing to 1.70 (1.02, 2.85) in the last decile (545.1-4,361.9 ng/kg). For IHD a numerical increase was first observed in the group with TEQ ranging from 278.6 to 545.0 ng/kg (RR 1.26; 0.67, 2.39). In the highest decile, a RR of 2.17 (1.18, 4.00) was observed. The trend tests were significant for both outcomes. Unlike for
cancer for CVD and IHD no increase in risk was observed in the lower dose ranges.