Derks HJGM ,
Berende PLM ,
Olling M ,
Liem AKD ,
Everts H ,
Jong APJM de
29 p
in Dutch
1991
Toon Nederlands
English Abstract Following a previously published report on an
investigation into the pharmacokinetics of 13C-labelled polychlorinated
dibenzo-p-dioxins and dibenzofurans administered orally as a bolus to
lactating cows, the present report describes the elimination kinetics of
unlabelled dioxins ingested by the same cows while being kept in
contaminated pastures in the Lickebaert-area. A control animal not knwon to
be exposed to dioxins in excess of background levels showed dioxin
concentrations in milk and subcutaneous fat as expected except for two
congeners indicating a possible accidental exposure to pentachlorophenol.
From the dioxin concentrations in milk and subcutaneous fat of the
Lickebaert cows half lifes could be calculated for nine congeners. In
general the elimination half lifes as judged from milk concentrations
appeared to be longer (45-110 d) than found previously for labelled dioxins.
This phenomenon was most striking for the higher substituted congeners. The
values found for the TEQ-dominating congeners did not differ essentially
from those found before. In subcutaneous fat half lifes appeared to be
shorter (25-40 d) than those derived from milk data. The discrepancies
between the milk and subcutaneous fat data observed here and between the
present results and those reported previously may be due to physiologic and
kinetic processes occurring in the lactating cow.
