Embryotoxic and teratogenic effects in unhatched fertile eggs from hens fed polychlorinated biphenyls (PCBs)

Summary The PCBs tested with caged White Leghorn hens were Aroclors 1221, 1232, 1242, 1248, 1254, 1268, 5442 and BP-6, fed at the 20 ppm level. In addition, 1242, 1248 and 1254 were also fed at the 2 ppm level. Feeding 20 ppm Aroclors 1232, 1242, 1248 and 1254 reduced hatchability and caused teratogenic effects in the embryos. The most common abnormalities found in the unhatched embryos were edema and unabsorbed yolk. Since Aroclors 1221 and 1268 did not adversely affect embryonic development, adverse effects of the PCBs were not directly related to the degree of chlorination of the biphenyls, or to the amount of total residue.