Biomonitoring of XXXX by measurement in hydrolysed urine and plasma after epicutaneous exposure in humans.

@entity5723 @entity20587 @entity1865
Five healthy volunteers were dermally exposed for 1 h to 0.75-2.25 mumol @entity20587 ( @entity1865 ) dissolved in @entity5723 , by use of a patch-test technique. Determination of @entity1865 remaining in the patch units after exposure showed that a median of 28% (range 25-29%) was absorbed. By analysis of hydrolysed plasma, an initial accumulation of @entity1865 could be shown, and then a decline. @entity1865 was also detected in hydrolysed urine. The maximum rate of @entity1865 excretion in urine was found 6-11 h after the onset of exposure. Within two subjects studied at three doses, the urinary excretion was proportional to the exposure. The elimination half-lives (elim-t1/2) in plasma and urine had medians of 13 and 7 h, respectively. In eight out of nine exposures, the elim-t1/2 was longer in plasma than in urine. Slow acetylation seemed to be associated with short elim-t1/2 in urine. The median of total @entity1865 amount excreted in urine during 48 h, was 33 nmol for the five subjects exposed to 0.75 mumol, which corresponded to roughly 16% (range 2%-26%) of the absorbed dose while only a limited number of individuals were studied, the data still indicated that @entity1865 in hydrolysed plasma or urine can be used for biological monitoring of occupational dermal exposure. However, the individual variation must be taken into account. Sampling should preferably be made several hours post shift. Urine is preferred before plasma at low exposures, because of its higher concentrations of @entity1865 .
