Quantitative relation of urinary phenol levels to breathzone benzene concentrations: a factory survey.

Abstract

Urine samples were collected from 64 men and 88 women in shoe factories and printing plants at the end of a seven hour day shift in the latter half of a week in spring. Urine samples were also taken from 43 men and 88 women in the same factories but who were not exposed to solvents. Exposure to benzene during the shift was monitored by passive dosimeters. Both phenol in urine and benzene in activated carbon were analysed with FID gas chromatographs. The urinary concentrations of phenol were linearly related to the time weighted average concentrations of benzene in the breathzone air; the variation was so small that those exposed to 10 ppm benzene could be separated from the non-exposed at least on a group basis when the phenol concentration was corrected either for creatinine concentration or for specific gravity. The urinary phenol concentrations corresponding to lOppm benzene were 47T5mg/1 (as observed), 57-9mg/g creatinine, or 46-6 mg/l (specific gravity 1*016).Benzene is considered to be a cause of human leukaemia' and occupational as well as nonoccupational exposure to this chemical has been a focus of keen attention. Among the biological indicators of exposure to benzene, urinary phenol has been most frequently used although it may be inferior to benzene in blood in its sensitivity and specificity,2 3 probably because urine is apparently much more readily available from factory workers than venous blood, and this is especially so in the case of the -general population. The existing data on the quantitative relation between exposure to benzene and urinary phenol excretion are, however, usually hampered by the technical limitations prevailing at the time of the study such as the low specificity of urinary phenol determination, the inability to measure average exposure during work, the small number of subjects, or a combination of these factors.2The present study was initiated to establish the quantitative exposure excretion relation, using passive samplers to determine the time weighted average exposure intensity of exposure to benzene and FID gas chromatography for the specific meaAccepted 21 January 1986 surement of phenol in urine. The results of studies with similar methodology have been described for toluene hippuric acid/o-cresol4 and tetrachloroethylene total trichloro compounds.5 Materials and methods EXAMINEESThe factory survey was conducted in the latter half of a week in spring. The workers exposed to benzene were 64 men (aged 26-9 + 8-4 years as arithmetic mean + arithmetic standard deviation (AM + ASD)) and 88 women (29-9 + 8-5 years) in five workshops in two shoe factories and two small printing plants. Control subjects were 43 men (39 3 + 119 years) and 88 women (26 9 + 8-4 years) who worked in the same factories but had not been exposed to solvents. Those under medical treatment with drugs were excluded. COLLECTION AND ANALYSES OF URINE SAMPLESEach subject was asked to pass urine at about 1300. The urine sahilple for analysis was collected at about 1500 when the seven hour shift was ...

Hypothesis: Phenol and hydroquinone derived mainly from diet and gastrointestinal flora activity are causal factors in leukemia

“…The urinary concentrations of phenol and hydroquinone varied widely (ie 5-to 25-fold) within a given population. [49][50][51] Some studies have reported differences in phenol levels between sexes, 54 whereas others have not. 48 Variability of phenol levels among individuals appears to be greater than the difference among males and females.…”

“…), urinary phenol levels were seen as a good biomarker for exposure to benzene. [46][47][48] Studies, such as those conducted by Inoue et al, 49,50 observed a significant correlation between air concentration of benzene in breathing zone and phenol or hydroquinone concentrations in urine (corrected for creatinine and specific gravity) ( Figure 2). The authors reported a significant difference between urinary phenol levels in a group exposed to 10 p.p.m.…”

“…benzene were indistinguishable from levels in unexposed individuals. 50 Likewise, the distributions of urinary hydroquinone levels of unexposed individuals overlapped with urinary levels from female workers exposed to benzene between 9 and 14 p.p.m. (7 h, time-weighted average).…”

“…However, in these and other studies, urinary phenol and hydroquinone were found to be poor predictors of lower benzene exposures. [48][49][50][51][52] For example, urinary phenol levels of workers exposed to 1 to 5 p.p.m. benzene were indistinguishable from levels in unexposed individuals.…”

“…High background concentrations of phenol, hydroquinone, catechol and 1,2,4-benzenetriol have been measured in the blood, urine and intestines of presumably unexposed humans [48][49][50][51][52][53][54][55][56][57][58][59][60][61][62] and in the blood and urine of rodents. [63][64][65] Representing measurements of hundreds of individuals in total, these studies showed that mean urinary phenol and hydroquinone levels were about 10 p.p.m.…”