Distribution of polychlorobiphenyls in pregnant mice and fetuses on various days of gestation

14C-2,4′,5-trichlorobiphenyl (test series A) and a laboratory mixture of14C-PCBs, which in addition to 2,4′,5-trichlorobiphenyl, contained dichlorobiphenyl and other trichlorobiphenyl isomers (test series B), were administered orally to pregnant mice on the 13th, 15th and 17th day post conceptionem (p.c.), respectively.