Abstract The PCBs tested with caged White Leghorn hens were Aroclors 1221, 1232, 1242, 1248, 1254, 1268, 5542 and BP-6 fed at the 20 p.p.m. level. In addition, 1242, 1248 and 1254 were also fed at the 2 p.p.m. level. None of these pollutants exerted any adverse effects on adult body weight gain, liv...