Urinary hippuric acid and orthocresol excretion in man during experimental exposure to toluene.

Publisher Website
Google Scholar
Abstract
It is not known whether urinary excretion of hippuric acid (HA) or o-cresol (O-Cr) is to be preferred for the biological monitoring of workers with occupational exposure to toluene. To study this, 42 printing trade workers with > 10 yr exposure to a mixture of organic solvents including toluene (0-20 ppm) and 43 control subjects matched by age, smoking habits and living accomodations were investigated. Each matched pair was randomized to an experimental exposure of 100 or 0 ppm toluene for 6.5 h under controlled conditions in an exposure chamber. Urinary excretion of HA and O-Cr was determined by high pressure liquid chromatography from samples obtained before exposure, during the 1st 3 h and during the last 3.5 h of exposure. No difference in HA and O-Cr excretion was found between printing trade workers and controls. The median O-Cr excretion increased 29-fold during exposure; the HA excretion increased only 5-fold. Only 3% of the O-Cr excretion originated from other sources than toluene; the corresponding value for HA was 19%. Standardization of the concentrations of HA and O-Cr in relation to urinary creatinine reduced the relative variation by 29 and 56%, respectively. This was not reduced further by expressing the excretions as average excretion rates based on total volume of urine collected. Background urinary O-Cr excretion was 3-4-fold higher among smokers than nonsmokers, probably due to the content of O-Cr in cigarettes. The O-Cr excretion in unexposed smokers was 10-fold lower than that of the nonsmokers during the end of the experimental exposure to 100 ppm toluene.

This publication has 8 references indexed in Scilit: