US EPA

2201055 

Journal Article 

Comparative metabolism of hexachlorobenzene and pentachloronitrobenzene in plants, rats, and rhesus monkeys 

Muller, WF; Scheunert, I; Rozman, K; Kogel, W; Freitag, D; Richter, E; Coulston, F; Korte, F 

1978 

Yes 

Ecotoxicology and Environmental Safety
ISSN: 0147-6513
EISSN: 1090-2414 

2 

3-4 

437-445 

English 

109270 

10.1016/S0147-6513(78)80017-7 

The uptake, biotransformation, and disposition of hexachlorobenzene (118741) (HCB) and pentachloronitrobenzene (82688) (PCNB) were studied in plants, rats, and rhesus-monkeys. The fate of HCB in summer wheat and soil was studied by treating seed wheat with 50 grams per 100 kilograms of carbon-14 labeled HCB and planting and growing the crop in a controlled climate chamber to maturity. After harvesting, soil, roots, straw, and seed were examined for HCB and metabolites. Rats were given 0.4 to 0.6 milligrams per kilogram labeled HCB by gastric intubation and excretion was monitored for 40 days. Six rhesus-monkeys were administered 1 part per million (ppm) HCB in the daily diet for 550 days. HCB excretion was measured and a storage curve was determined. PCNB was also fed to rhesus-monkeys at 2ppm daily and metabolism and storage were compared with HCB. The recovery of radioactivity from the wheat and soil was 27.4 percent, with 99.1 percent in soil and roots and 0.17 percent in seeds (0.02ppm). No metabolites were found. In rats, the bulk of the radioactivity was excreted in the feces, mostly as HCB. Three to 4 percent was identified as pentachlorobenzene (608935) (PCB). Throughout the study of HCB excretion in monkeys, metabolism rate and urinary excretion increased steadily. Urinary excretion began at less than 1 percent and rose to 7 percent of the total administered dose by day 450; fifty percent was excreted as PCB and the rest largely as HCB. Fecal excretion also increased steadily, to 52 percent by day 450. PCNB excretion also increased steadily, to 52 percent by day 450. PCNB excretion rose only for 30 to 40 days, resulting in a storage plateau of only 2 to 3 percent of the administered dose. HCB was mainly stored in omental fat, bone marrow, and thymus; slightly elevated concentrations of PCNB occurred in liver, kidney, and thymus. The authors conclude that the cumulative storage of HCB in the rhesus-monkey is approximately 20 times greater than that of PCNB.