US EPA

63269 

Journal Article 

Chronic low dose exposure of rhesus monkeys to hexachlorobenzene (HCB) 

Rozman, K; Mueller, WF; Coulston, F; Korte, F 

1978 

Yes 

Chemosphere
ISSN: 0045-6535
EISSN: 1879-1298 

2 

2 

177-184 

English 

10.1016/0045-6535(78)90045-0 

WOS:A1978ET39900007 

The metabolism and storage of chronic low doses of hexachlorobenzene (118741) (HCB) were investigated in rhesus-monkeys. Six monkeys received 110 micrograms (microg) of carbon-14 labelled HCB daily for 18 months. The dose was 1.0 parts per million of daily food intake. Urine and feces were collected and excreted radioactivity was counted. Quantitative determination of HCB and metabolites was performed with a gas chromatograph. Blood radioactivity values were measured and serum hormone and enzyme values were determined. Urinary coproporphyrin and uroporphyrin contents were assayed. Fat biopsies were performed. One male was sacrificed after 18 months and body distribution of HCB was determined. Results were compared with those from untreated control. Total excretion of HCB increased from initial values of about 1 percent of total dose in urine and 20 percent in feces to 6 percent in urine and 50 percent in feces after 550 days. Fecal excretion of radioactivity consisted of 99 percent HCB, about 1 percent pentachlorobenzene (608935) (PCB) and traces of pentachlorophenol (87865) (PCPh). The main urinary metabolite was PCPh, varying between 50 and 75 percent of urinary radioactivity with the remainder as PCB, HCB, and tetrachlorobenzene (95943). Coproporphyrin values were decreased by 50 percent in treated males, but doubled in treated females; uroporphyrin content of urine was slightly increased in treated males and decreased in females. Enzyme values were within normal limits. Blood radioactivity slowly increased to about 7 times initial values; fat HCB increased to 4 times initial values. Body distribution of HCB showed the greatest concentration in fat, bone marrow, thymus, adrenal cortex, large intestinal lymph nodes, and tongue. The authors conclude that HCB is a highly lipophilic compound, mainly absorbed through the lymphatic system and deposited in fat. Increasing storage accompanies increasing blood values and enhanced urinary excretion. None of the monitored parameters indicate harmful effects of 110microg per day HCB over 550 days.