| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4414866 | Chemosphere | 2007 | 8 Pages |
BackgroundPolychlorinated biphenyls are toxic and slowly degrading substances that have been in widespread industrial use in the 1960s and 1970s. Despite a worldwide reduction, environmental exposure remains an issue; the assessment of an individual’s level of exposure at a given time in retrospect requires valid toxicokinetic modeling of the different PCB congeners.ObjectivesTo develop and verify a toxicokinetic model of the in vivo-degradation of PCB 28 and 52 in adult humans.MethodsThe plasma concentrations of PCB congeners were measured in 583 persons working in a contaminated building for an average of 14.7 ± 9.6 years. The values were adapted to a simple pharmacokinetic model (yt = y0 × (1 − e−kt)); the steady state concentration y0 was estimated based on the median values of persons working exposed more than 10 years.ResultsThe steady state concentration of PCB 28 was 0.10 μg/l, that of PCB 52 0.02 μg/l. The half-life of the congeners was estimated based on a logarithmic regression analysis according to the model mentioned above; it was 2.18 (95% CI: 1.91–2.54) years for PCB 28 and 3.95 (95% CI: 3.55–4.45) years for PCB 52, respectively. Stepwise elimination of persons with very long employment duration did not reduce the estimated half-life.ConclusionsThe estimated half-life is higher than previously published data especially for PCB 52. Possible reasons and implications of this finding are discussed.
