Bm. Derooij et al., ALLYLMERCAPTURIC ACID AS URINARY BIOMARKER OF HUMAN EXPOSURE TO ALLYLCHLORIDE, Occupational and environmental medicine, 54(9), 1997, pp. 653-661
Objective-To evaluate the use of urinary mercapturic acids as a biomar
ker of human exposure to allyl chloride (3-chloropropene) (AC). During
three regular shut down periods in a production factory for AC, both
types of variables were measured in 136 workers involved in maintenanc
e operations. Methods-Potential airborne exposure to AC was measured b
y personal air monitoring in the breathing zone. In total 205 workshif
ts were evaluated. During 99 workshifts no respiratory protection equi
pment was used. Mercapturic acid metabolites were measured in urinary
extracts by gas chromatography-mass spectrometry (GC-MS). Results-Duri
ng 86 work shifts when no respiratory protection was used the air conc
entrations of AC were below the Dutch eight hour time weighted average
(8h-TWA) occupational exposure Limit (GEL) of AC (3 mg/m(3)), whereas
in 13 workshifts the potential exposure, as measured by personal air
monitoring, exceeded the OEL (3.3 to 17 mg/m(3)). With the aid of GC-M
S, 3-hydroxypropylmercapturic acid (HPMA) was identified as a minor an
d allylmercapturic acid (ALMA) as a major metabolite of AC in urine sa
mples from the maintenance workers exposed to AC. The concentrations o
f ALMA excreted were in a range from < 25 mu g/l (detection limit) to
3550 mu g/l. The increases in urinary ALMA concentrations during the w
orkshifts correlated well. with the 8h-TWA air concentrations of AC (r
= 0.816, P=0.0001, n = 39). Based on this correlation, for AC a biolo
gical exposure index (BEI) of 352 mu g ALMA/g creatinine during an eig
ht hour workshift is proposed. In some urine samples unexpectedly high
concentrations of ALMA were found. Some of these could definitely be
attributed to dermal exposure to AC. In other cases garlic consumption
was identified as a confounding factor. Conclusion-The mercapturic ac
id ALMA was identified in urine of workers occupationally exposed to a
irborne AC and the increase in ALMA concentrations in urine during a w
orkshift correlated well with the 8h-TWA exposure to AC. Garlic consum
ption, but not smoking, is a potential confounding factor for this bio
marker of human exposure to AC.