1-Hydroxypyrene concentrations in first morning voids and 24-h composite urine: intra- and inter-individual comparisons.
Urinary 1-hydroxypyrene (1-OHP) has been suggested as an exposure biomarker for polycyclic aromatic hydrocarbons (PAHs). However, it remains unknown whether a first morning urine sample can be used to reflect average exposure. In this paper, we examine intra-individual differences and inter-individual associations between first morning voids and 24-h composite urine samples. The analysis was performed using data collected from 100 adults who had a wide range of PAH exposure due to differences in their occupation, e.g., coke oven workers vs. non-coke oven workers. For each subject, all the urine voids within each of two 24-h measurement periods were collected. Results showed a significant (40% to 62%) intra-individual difference between first morning voids and 24-h urinary 1-OHP concentrations (in ng/ml urine). Creatinine adjustments of 1-OHP concentrations (in micromol/mol urinary creatinine) reduced the intra-individual difference by approximately 10%. Across all the subjects, a high overall correlation (r=0.76) was observed between first morning and 24-h average 1-OHP concentrations. Work environment and sampling season were found to significantly affect the relationship between first morning and 24-h 1-OHP concentrations. An increase of 1 ng/ml of first morning urinary 1-OHP predicted an increase of 0.5 and 0.25 ng/ml of 24-h urinary 1-OHP for coke oven workers and non-coke oven workers, respectively. Data collected in a winter season showed a higher correlation between first morning and 24-h concentrations than data collected in a fall season. Creatinine adjustments did not significantly improve overall correlations between first morning void and 24-h measurements, but increased total variances for 24-h urines explained by first morning urines in coke workers.
Han
In-Kyu
IK
School of Public Health, Department of Environmental and Occupational Health, University of Medicine and Dentistry of New Jersey, 683 Hoes Lane West, Piscataway, New Jersey 08854, USA.
Duan
Xiaoli
X
Zhang
Lin
L
Yang
Hongbiao
H
Rhoads
George G
GG
Wei
Fusheng
F
Zhang
Junfeng
J
D000328:Adult; D001580:Benzopyrenes / Q000032:analysis; D015415:Biomarkers / Q000652:urine*; D002681:China; D003077:Coke; D003404:Creatinine / Q000652:urine; D004784:Environmental Monitoring; D005260:Female; D006801:Humans; D007221:Industry; D007407:Interviews as Topic; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000032:analysis*; D009790:Occupations / Q000145:classification; D011084:Polycyclic Aromatic Hydrocarbons / Q000652:urine*; D011721:Pyrenes / Q000032:analysis* / Q000378:metabolism; D012621:Seasons; D013997:Time Factors; D014556:Urine / Q000737:chemistry*
D001580:Benzopyrenes; D015415:Biomarkers; D003077:Coke; D011084:Polycyclic Aromatic Hydrocarbons; D011721:Pyrenes; D003404:Creatinine; C033146:1-hydroxypyrene