Effect of alcohol on the kinetics of mandelic acid excretion in volunteers exposed to styrene vapour.

Abstract

ABsTRAcr The effect of a dose of alcohol on the kinetics of mandelic acid excretion in four volunteers exposed to 220 mg/m3 styrene has been investigated under controlled exposure chamber conditions. Ethanol inhibited the excretion of mandelic acid, so that the peak excretion was delayed from the end of the exposure period until three hours afterwards. One hour after administration of ethanol blood mandelic acid concentrations were 56% of the levels found during the alcohol-free control exposure, and this was paralleled by a 15-fold rise in phenylethane 1,2 diol, the metabolic precursor of mandelic acid. It is suggested that the inhibition of the oxidation of this diol is related to the change in NAD+/NADH ratio produced by ethanol metabolism. The implications of this ethanol effect on the interpretation of urinary mandelic acid excretion when monitoring workers exposed to styrene are discussed.It is now established that monitoring workers exposed to styrene vapour is best accomplished by measuring the excretion of mandelic acid in the urine.1-5 The usefulness of mandelic acid determinations depends on the time of taking the urine sample after the end of the workshift.6 Several authors have suggested end-of-shift sampling while others have recommended next-morning samples."--In an earlier study we reported a detailed investigation of the daily excretion of mandelic acid by two technicians building glass-reinforced plastic boats under model ventilation conditions.7 Both these subjects showed maximum mandelic excretion several hours (4-8 hours) after the end of exposure. The time-lag was relatively constant for each individual and not related to level of exposure. We suggested that such a time lag in maximum excretion rates required a modification of sampling strategy. Our report of this time-lag in excretion has caused some controversy. Guillemin and Bauer"2 reviewed those papers reporting a time-lag and have contrasted these reports with their experience that experiments with volunteers under controlled exposure-chamber conditions show that maximum excretion occurs at or near the end of exposure. Since their publication we have confirmed that under controlled exposure chamber conditions maximum excretion of mandelic Received 15 March 1982 Acccepted 7 May 1982 acid does occur at the end of the exposure period. On the other hand, we have also found that a significant proportion of industrial workers in the glass-reinforced plastic boat industry that we have studied in detail show a delayed excretion of mandelic acid. This difference in excretion kinetics between volunteers under controlled conditions, and workers building glass-reinforced plastic boats requires explanation. Among the factors considered was the effect of the ingestion of alcohol. Alcohol affects the metabolism of xylene, toluene, and trichloroethylene."3-16 In this study we have investigated the effect of alcohol ingestion on the excretion of mandelic acid by volunteers under controlled exposure conditions.

Urinary mandelic acid and hemoglobin adducts in fiberglass-reinforced plastics workers exposed to styrene.

“…Since there was no ethanol used in the production process, the presence of ethanol in the breathin g zone (air sa mples) ind icated the int ake of a subs tantia l amo unt of alco hol by some workers be fore wor k or during the breaks. Wilson et al (12) and Berode et al ( 13) rep orted the kinetics of mandelic acid excretion to be substantially altered in hum an volunteers exposed to both styrene and ethanol. Also in this study, a highly significant interaction wa s found between alcoho l intake before or during work and styrene ex pos ure, a finding indicating that alco hol intake sig nificantly delays mand eli c acid excretion.…”

Re: "Urinary styrene in the biological monitoring of styrene exposure" by F Gobba, C Galassi, S Ghittori, M Imbriani, F Pugliese, A Cavaleri. Scand J Work Environ Health 1993; 19:175-82.

“…However, recentl y, another reputable group in an equally well planned and executed stud y came to rather opposite conclusio ns (2). It would be interesting if Dr Gobba and his co-workers would comment on this work, and also, if they can, compare the slopes or intercepts of the regression lines given in these two studies on the relationship between air and urinary styrene concentrations (which are very similar in seve ral published studies on the relat ionship between airborne styrene and the urinary excret ion of mandel ic acid and phenylglyoxylic ac id (3)(4)(5)(6)(7) .…”

Effect of ethanol on the urinary excretion of cyclohexanol and cyclohexanediols, biomarkers of the exposure to cyclohexanone, cyclohexane and cyclohexanol in humans

“…The consumption of alcoholic beverages shortly before or during a workshift (or in model laboratory experiments) modifies urinary levels of metabolites of styrene (6), xylenes (7), trichloroethylene (8) and other solvents significantly. As to CH-one, CH, or CH-01, the reduction of CH-one to CH-01 (the primary step in the metabolism of CH-one) is catalyzed by ADH (9), while the oxidation of C H to CH-01 (the primary step in the metabolism of CH) is mediated by the P450 system enzymes (10).…”