Decrease of PCDD/F levels in human blood from Germany over the past ten years (1989–1998)

744 whole blood samples of normal subjects from Germany collected in 1989–1998 have been analyzed for polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) by capillary gas chromatography/high resolution mass spectrometry. Over the examined time period a continuous decrease of the PCDD/F concentrations in human blood was observed. The mean levels found were 43.7 pg I-TEq/g (lipid basis) in 1989 and 20.7 pg I-TEq/g (lipid basis) in 1996/98 {median: 42.2 and 19.4}. The reduction to about the half was found for most congeners. Each one-year subset of the collective and the entire collective shows a positive correlation of the PCDD/F blood levels with age for most of the congeners, the sum values and the calculated toxicity equivalents. For statistical evaluation a multiplicative model was used: Concentration=A•AgeB The correlation is mostly pronounced for lower chlorinated PCDD and for 2,3,4,7,8-PentaCDF. The PCDD/F concentrations in human blood in relation to the year of examination and the age of the subjects can be described by a linear model: I-TEq [pg/g (lipid basis)]=6176 − 3.097 • Year + 0.6482 • Age or by a multiplicative model: I-TEq [pg/g(lipid basis)]=1089.08−0.04415•Year+0.008468•Age.