Variability and exposure classification of urinary phenol and paraben metabolite concentrations in reproductive-aged women

Abstract

Background Human exposure to phenols and parabens is widespread. Within-person variability of urinary concentrations in healthy women is not well characterized. Objectives To characterize the variability of urinary phenol and paraben concentrations across two months and evaluate the ability of a single spot urine sample to characterize exposure. Methods 143 women provided 509 spot urine samples collected across two months of study (3–5 samples/woman). We measured urinary concentrations of 8 phenols: bisphenol A (BPA), benzophenone-3 (BP-3), benzophenone-1 (BP-1), 2,4-dichlorophenol (2,4-DCP), 2,5-dichlorophenol (2,5-DCP), 2,4,5-trichlorophenol (2,4,5-TCP), 2,4,6-trichlorophenol (2,4,6-TCP), triclosan (TCS); and 8 parabens and their metabolites (benzyl (BzP), butyl (BuP), ethyl (EtP), heptyl (HeP), methyl (MeP), propyl (PrP), 4-hydro-xybenzoic acid (4-HB), 3,4-dihydroxybenzoic acid (3,4-DHB)). Biomarker variability was characterized using the intraclass correlation coefficient (ICC) and surrogate category analyses were conducted. Results ICCs ranged from very low for BPA (0.04) to moderate for BP-3, BP-1, TCS, BzP, and MeP (0.66, 0.58, 0.55, 0.54, and 0.62, respectively). Surrogate analyses suggested that BP-1, BP-3, TCS, 2,4-DCP, BuP, and PrP may be characterized by a single spot sample (sensitivity range 0.76–0.86) but that additional samples were necessary for BPA, HeP, 4-HB, and 3,4-DHB (sensitivity range 0.47–0.61). Conclusions Urinary phenol and paraben metabolite concentrations were variable across two months in healthy women but the degree of reliability differed by the specific biomarker. A small number of samples may sufficiently characterize typical concentrations for BP-3, BP-1, TCS, BuP, and PrP; but additional biospecimens may be necessary to characterize exposure for other compounds, including BPA.

Elevated concentrations of urinary triclocarban, phenol and paraben among pregnant women in Northern Puerto Rico: Predictors and trends

“…Among studies that have reported individual variability in repeated measurements of urinary phenols concentrations, BPA has been investigated the most in different populations. The observed ICC for BPA measurements in our study (0.09) is in agreement with the studies which have reported similarly very low to moderate ICCs of around 0.04–0.43 (Braun et al 2011a; Engel et al 2014; Guidry et al 2015; Lassen et al 2013; Mahalingaiah et al 2008; Nepomnaschy et al 2009; Pollack et al 2016; Reeves et al 2014; Teitelbaum et al 2008; Ye et al 2011a), where higher ICCs correspond to studies with shorter time frame between repeated samples. Findings from many studies suggest that multiple measurements are needed to reflect long-term exposure to BPA rather than a single measurement.…”

Endocrine disrupting chemical exposure and maladaptive behavior during adolescence

“…In addition, study-specific urine qa/qc samples demonstrated excellent reproducibility (See Supplemental Methods: QA/QC Assessment of Biomarker Analyses and Supplemental Tables 1-4). Intraclass Correlation Coefficients (ICCs) of urinary biomarker concentrations for participants who provided two urine samples ranged from 0.05 to 0.93 which is consistent with the expectation of substantial variability in exposure to some phthalates and phenols even within a relatively short time interval (Supplemental Table 5) (Pollack et al, 2016;Valvi et al, 2015).…”

Environmental levels of triclosan and male fertility

“…Additionally, studies of temporal variability in urinary excretion of TCS have indicated reasonable temporal consistency in triclosan excretion (Lassen et al 2013 ). Also, Pollack et al 2016 demonstrated fair to good reliability for one urine sample for TCS. Second, since this is a cross-sectional study, the nature of this study does not allow the determination of causality of the observed associations.…”