THE URINARY-EXCRETION OF SOLVENTS AND GASES FOR THE BIOLOGICAL MONITORING OF OCCUPATIONAL EXPOSURE - A REVIEW

'In the field' application of the measurement of urinary excretion of unmodified solvent for the biological monitoring of exposed workers ha s been investigated in many recent papers. The results obtained for se veral solvents are reviewed. The values of correlation coefficients (r ) and regression lines obtained for benzene, toluene, xylene, styrene, n-hexane, cyclohexane, 2- and 3-methylpentane, methyl chloride, tetra chloroethylene, carbon tetrachloride, methyl chloroform, p-dichloroben zene, nitrous oxide, halothane, isoflurane, enflurane, acetone, methyl ethyl ketone and methyl isobutyl ketone are presented. The correlatio ns observed were generally good: r values range from 0.50-0.97, and th e majority are between 0.84 and 0.90. The regression lines reported fa r the same solvent in different studies present some variability: this is possibly due to an inadequate control of factors influencing the r elationship between external dose and absorption, such as differences in body burden, work load, individual characteristics, etc. These fact ors are discussed. As a whole, results reported in the literature show that measuring of urinary excretion of unmodified solvents provides a highly sensitive and specific exposure index, and can also be applied for the biological monitoring of occupational exposure to low levels of solvents or to solvent mixtures. Nevertheless, for an adequate asse ssment of biological limit values, further studies evaluating the repr oducibility of regression lines are needed, given that the aspects inf luencing the correlation between external dose and urinary excretion a re fully controlled. Another crucial aspect is the correlation with ea rly effects: even though this has yet to be evaluated for several solv ents, for others such as styrene and perchloroethylene a good correlat ion was obtained, further supporting the usefulness of the measurement of urinary excretion of solvent for the biological monitoring of occu pational exposure. (C) 1997 Elsevier Science B.V.