Predictors and variability of urinary paraben concentrations in men and women, including before and during pregnancy.
BACKGROUND
Parabens are suspected endocrine disruptors and ubiquitous preservatives used in personal care products, pharmaceuticals, and foods. No studies have assessed the variability of parabens in women, including during pregnancy.


OBJECTIVE
We evaluated predictors and variability of urinary paraben concentrations.


METHODS
We measured urinary concentrations of methyl (MP), propyl (PP), and butyl paraben (BP) among couples from a fertility center. Mixed-effects regression models were fit to examine demographic predictors of paraben concentrations and to calculate intraclass correlation coefficients (ICCs).


RESULTS
Between 2005 and 2010, we collected 2,721 spot urine samples from 245 men and 408 women. The median concentrations were 112 µg/L (MP), 24.2 µg/L (PP), and 0.70 µg/L (BP). Urinary MP and PP concentrations were 4.6 and 7.8 times higher in women than men, respectively, and concentrations of both MP and PP were 3.8 times higher in African Americans than Caucasians. MP and PP concentrations were slightly more variable in women (ICC = 0.42, 0.43) than men (ICC = 0.54, 0.51), and were weakly correlated between partners (r = 0.27-0.32). Among 129 pregnant women, urinary paraben concentrations were 25-45% lower during pregnancy than before pregnancy, and MP and PP concentrations were more variable (ICCs of 0.38 and 0.36 compared with 0.46 and 0.44, respectively).


CONCLUSIONS
Urinary paraben concentrations were more variable in women compared with men, and during pregnancy compared with before pregnancy. However, results for this study population suggest that a single urine sample may reasonably represent an individual's exposure over several months, and that a single sample collected during pregnancy may reasonably classify gestational exposure.
Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA.
Kristen W
KW
Smith
Joe M
JM
Braun
Paige L
PL
Williams
Shelley
S
Ehrlich
Katharine F
KF
Correia
Antonia M
AM
Calafat
Xiaoyun
X
Ye
Jennifer
J
Ford
Myra
M
Keller
John D
JD
Meeker
Russ
R
Hauser
D000328:Adult; D000367:Age Factors; D002851:Chromatography, High Pressure Liquid; D015331:Cohort Studies; D004781:Environmental Exposure; D004784:Environmental Monitoring; D005260:Female; D005520:Food Preservatives / Q000378:metabolism*; D006801:Humans; D016014:Linear Models; D008297:Male; D008404:Massachusetts; D008875:Middle Aged; D010226:Parabens / Q000378:metabolism*; D011247:Pregnancy; D011310:Preservatives, Pharmaceutical / Q000378:metabolism*; D011446:Prospective Studies; D012737:Sex Factors; D012959:Socioeconomic Factors; D053719:Tandem Mass Spectrometry; D055815:Young Adult
D005520:Food Preservatives; D010226:Parabens; D011310:Preservatives, Pharmaceutical; C038091:butylparaben; C015358:methylparaben; C006068:propylparaben