Phenol urinary elimination

Some phenol is eliminated from the body as the unchanged molecular compound, although most is metabolized prior to excretion. As noted in Section 7.2.1, phase II reactions in the body result in the conjugation of phenol to produce sulfates and glucuronides. These water-soluble metabolic products are eliminated via the kidneys. Urinary phenyl glucuronide may be measured to monitor exposure to phenol.7... 

Finally, the fact that anthocyanins can reach the brain represents a beginning of an explanation of the purported neuroprotection effects of anthocyanins. Anthocyanins may be eliminated via urinary and biliary excretion routes. " The extent of elimination of anthocyanins via urine is usually very low (< 0.2% intake) in rats and in humans, indicating either a more pronounced elimination via the bile route or extensive metabolism. As mentioned earlier, in the colon, non-absorbed or biliary excreted anthocyanins can be metabolized by the intestinal microflora into simpler break-down compounds such as phenolic acids that may be (re)absorbed and conjugated with glycine, glucuronic acid, or sulfate and also exhibit some biological... 

Both urinary and fecal excretion of 14C was determined in rats administered an oral dose of 1.2 mg/kg of [14C]-labeled phenol (Edwards et al. 1986). Rats excreted 80.3 11.2% in the urine and 1.8 1.6%inthe feces in 24 hours. In rats exposed orally to radiolabeled phenol, elimination was 95% complete after 72 hours, with the primary elimination route being through the urine (Hughes and Hall 1995). Fecal elimination was slower and less overall. 

In vivo experiments on 4 human volunteers, to whom 0.0026 mg/cm2 of 14C-benzene was applied to forearm skin, indicated that approximately 0.05% of the applied dose was absorbed (Franz 1984). Absorption was rapid, with more than 80% of the total excretion of the absorbed dose occurring in the first 8 hours after application. Calculations were based on urinary excretion data and no correction was made for the amount of benzene that evaporated from the applied site before absorption occurred. In addition, the percentage of absorbed dose excreted in urine that was used in the calculation was based only on data from rhesus monkeys and may not be accurate for humans. In another study, 35-43 cm2 of the forearm was exposed to approximately 0.06 g/cm2 of liquid benzene for 1.25-2 hours (Hanke et al. 1961). The absorption was estimated from the amount of phenol eliminated in the urine. The absorption rate of liquid benzene by the skin (under the conditions of complete saturation) was calculated to be low, approximately 0.4 mg/cm2/hour. The absorption due to vapors in the same experiment was negligible. The results indicate that dermal absorption of liquid benzene is of concern, while dermal absorption from vapor exposure may not be of concern because of the low concentration of benzene in vapor form at the point of contact with the skin. No signs of acute intoxication due to liquid benzene dermally absorbed were noted. These results confirm that benzene can be absorbed through skin. However, non-benzene-derived phenol in the urine was not accounted for. 

Chelation therapy in individuals exposed to gasoline indicates that inorganic lead is eliminated in the urine of patients exposed to leaded gasoline (Robinson 1978). Urinary phenol, which is commonly used to indicate benzene exposure, was measured in gasoline pump workers (Pandya et al. 1975). There was an elevated amount of phenol (40 mg/L) in these subjects compared to normal values (<... 

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