Toxicity and bioaccumulation of pentachlorophenol in broiler chickens

Hubbard-Hubbard broiler chickens were fed graded levels (0, 1, 10, 100, and 1000 ppm) of pentachlorophenol (PCP) containing less than .0023% octachlorodibenzo-p-dioxin (OCDD) for 8 weeks. Tissue samples for PCP, OCDD, and pentachloroanisole (PCA) were cleaned up via gel permeation chromatography and analyzed by gas chromatography employing electron capture detection. Kidney weights were significantly increased by the 100 ppm and 1000 ppm PCP diet. Weights of all other organs including the body weights were significantly lowered by the 1000 ppm PCP diet. Except for the control group, histopathologic examination of the liver revealed bile duct proliferation and some fatty changes in all of the 6-week-old birds. Examination of the brain, liver, gizzard, pancreas, intestine, proventriculus, spleen, kidney, lung, and heart revealed no histopathological lesions in the treated or control birds. Significant linear relationships were found between PCP accumulation in tissues and the concentration of dietary PCP. Accumulation of PCP was greatest in the kidney followed by liver, heart, leg, breast, gizzard, and fat. The high residue levels in the kidney and liver may reflect principal routes of elimination and metabolism. Following a 5 week withdrawal of PCP from the diet, PCP residues were still present in the adipose tissue of all treated birds. Residue levels in the kidney and liver were reduced at the first and third week of withdrawal, but a continuous decline was interrupted by a slight elevation in residue level at the fifth week of withdrawal from the chemical.