ELIMINATION OF POLYCHLORINATED DIBENZO-p-DIOXINS AND DIBENZOFURANS IN OCCUPATIONALLY EXPOSED PERSONS

Abstract

The elimination of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) was investigated in a group of n=43 exposed workers with 2 blood measurements and n=5 workers with 3 measurements. Under the assumption of a one-compartment, first-order kinetic m odel the median half-life for 2,3,7,8-TCDD was 7.2 yr, while for the other dioxins the estimates were between 3.7 yr for 1,2,3,4,6,7,8-HpCDD (hepta-chlorinated) and 15.7 yr for 1,2,3,7,8-PCDD (penta-chlorinated). For the furans median half-lives between 3.0 yr for 1,2,3,4,6,7,8-HpCDF and 19.6 yr for 2,3,4,7,8-PCDF were observed. There was no indication for a deviation from a first-order kinetic. Increasing age and percent body fat were associated with increasing half-life for most of the congeners. Smokers in general had a faster decay than non-and ex-smokers. In summary, the higher chlorinated PCDD/F like TCDD appear to be highly persistent in humans with half-lives ranging between 4 and 12 yr.