Temporal variability in urinary excretion of bisphenol A and seven other phenols in spot, morning, and 24-h urine samples.
Human exposure to modern non-persistent chemicals is difficult to ascertain in epidemiological studies as exposure patterns and excretion rates may show temporal and diurnal variations. The aim of this study was to assess the temporal variability in repeated measurements of urinary excretion of bisphenol A (BPA) and seven other phenols. All analytes were determined using TurboFlow-LC-MS/MS. Two spot, three first morning and three 24-h urine samples were collected from 33 young Danish men over a three months period. Temporal variability was estimated by means of intraclass correlation coefficients (ICCs). More than 70% of the urine samples had detectable levels of BPA, triclosan (TCS), benzophenone-3 (BP-3) and sum of 2,4-dichlorophenol and 2,5-dichlorophenol (ΣDCP). We found low to moderate ICCs for BPA (0.10-0.42) and ΣDCP (0.39-0.72), whereas the ICCs for BP-3 (0.69-0.80) and TCS (0.55-0.90) were higher. The ICCs were highest for the two spot urine samples, which were collected approximately 4 days apart, compared with the 24-h urine samples and the first morning urine samples, which were collected approximately 40 days apart. A consequence of the considerable variability in urinary excretion of BPA may be misclassification of individual BPA exposure level in epidemiological studies, which may lead to attenuation of the association between BPA and outcomes. Our data do not support that collection of 24-h samples will improve individual exposure assessment for any of the analysed phenols.
Rigshospitalet, Copenhagen University Hospital, Department of Growth and Reproduction, Blegdamsvej 9, 2100 Copenhagen, Denmark. Electronic address: tina.harmer.lassen@rh.regionh.dk.
Tina Harmer
TH
Lassen
Hanne
H
Frederiksen
Tina Kold
TK
Jensen
Jørgen Holm
JH
Petersen
Katharina M
KM
Main
Niels E
NE
Skakkebæk
Niels
N
Jørgensen
Selma Kløve
SK
Kranich
Anna-Maria
AM
Andersson
D001559:Benzhydryl Compounds / Q000652:urine*; D002940:Circadian Rhythm; D004785:Environmental Pollutants / Q000652:urine*; D006801:Humans; D008297:Male; D010636:Phenols / Q000652:urine*; D013997:Time Factors; D000098826:Bisphenol A Compounds
D001559:Benzhydryl Compounds; D004785:Environmental Pollutants; D010636:Phenols; C006780:bisphenol A; D000098826:Bisphenol A Compounds
2,4,5-TCP; 2,4,5-trichlorophenol; 2,4-DCP; 2,4-dichlorophenol; 2,5-DCP; 2,5-dichlorophenol; 2-PP; 2-phenylphenol; 4-PP; 4-phenylphenol; BP-3; BPA; Benzophenone-3; Bisphenol A; Epidemiology; TCC; TCS; Temporal variability; Triclosan; benzophenone-3; bisphenol A; sum of 2,4-dichlorophenol and 2,5-dichlorophenol; triclocarban; triclosan; ΣDCP