Variability and predictors of urinary organophosphate ester concentrations among school-aged children.

Organophosphate esters (OPE) are flame retardants and plasticizers used in a wide range of consumer products. Despite their widespread use, few studies have characterized pediatric exposures. We assessed variability and predictors of OPE exposures in a cohort panel study of 179 predominantly Black school-aged children with asthma in Baltimore City, MD. The study design included up to four seasonal week-long in-home study visits with urine sample collection on days 4 and 7 of each visit (nsamples = 618). We quantified concentrations of 9 urinary OPE biomarkers: bis(2-chloroethyl) phosphate (BCEtp), bis(1-chloro-2-propyl) phosphate, bis(1,3-dichloro-2-propyl) phosphate (BDCPP), di-benzyl phosphate (DBuP), di-benzyl phosphate, di-o-cresylphosphate, di-p-cresylphosphate (DPCP), di-(2-propylheptyl) phthalate (DPHP), 2,3,4,5-tetrabromo benzoic acid. We assessed potential predictors of exposure, including demographic factors, household characteristics, and cleaning behaviors. We calculated Spearman/tetrachoric correlations and intraclass correlation coefficients (ICCs) to examine within-week and seasonal intra-individual variability, respectively. We assessed OPE predictors using linear models for continuous log2 concentrations (BDCPP and DPHP) and logistic models for odds of detection (BCEtP, DBuP, DPCP), with generalized estimating equations to account for repeated measures. For all OPEs, we observed moderate within-week correlations (rs: 0.31-0.63) and weak to moderate seasonal reliability (ICC: 0.18-0.38). BDCPP and DPHP concentrations were higher in the summer compared to other seasons. DPHP concentrations were lower among males than females (%diff: -53.5%; 95% CI: -62.7, -42.0) and among participants spending >12 h/day indoors compared to ≤12 h (%diff: -20.7%; 95% CI: -32.2, -7.3). BDCPP concentrations were lower among children aged 8-10 years compared to 5-7 years (%diff: -39.1%; 95% CI: -55.9, -15.9) and higher among children riding in a vehicle on the day of sample collection compared to those who had not (%diff: 28.5%; 95% CI: 3.4, 59.8). This study is the first to characterize within-week and seasonal variability and identify predictors of OPE biomarkers among Black school-aged children, a historically understudied population.

Louis LM ，Quirós-Alcalá L ，Kuiper JR ，Diette G ，Hansel NN ，McCormack MC ，Meeker JD ，Buckley JP ... -  《-》

Exposures to Organophosphate Esters and Respiratory Morbidity among School-Aged Children with Asthma.

Louis LM ，Buckley JP ，Kuiper JR ，Meeker JD ，Hansel NN ，McCormack MC ，Diette G ，Quirós-Alcalá L ... -  《-》

Urinary organophosphate ester concentrations in relation to ultra-processed food consumption in the general US population.

Ultra-processed foods are highly processed foods which are manufactured with industrial substances to increase convenience and palatability. Some organophosphate esters (OPEs) are used as flame retardants and plasticizers and have been detected in food samples, particularly processed foods. However, little is known about dietary sources of OPEs or whether higher consumption of ultra-processed foods increases exposures. We evaluated whether higher consumption of ultra-processed food is associated with urinary OPE metabolite concentrations in a nationally representative sample of US children and adults. Among 2242 participants (≥6 years) in the National Health and Nutrition Examination Survey (NHANES) 2013-2014, we used the NOVA classification system to calculate percent of total energy from ultra-processed food using a 24 h dietary recall. Concentrations of 7 OPE metabolites, including diphenyl phosphate (DPHP), bis(1,3-dichloro-2-propyl) phosphate (BDCPP), bis(2-chloroethyl) phosphate (BCEP), dibutyl phosphate (DBUP), di-p-cresyl phosphate (DPCP), 2,3,4,5-tetrabromobenzoic acid (TBBA), and bis(1-chloro-2-propyl) phosphate (BCPP) were measured in urine. We used multivariable linear or logistic regressions to examine associations per 10% higher total energy from ultra-processed foods with percent changes or prevalence of detectable levels of creatinine-standardized OPEs. In a model adjusting for only urinary creatinine, each 10% higher total energy from ultra-processed food was associated with 3.5% (95% CI: 0.7%, 6.3%) higher DPHP and 8.2% (95% CI: 4.6, 11.9%) higher BDCPP concentrations. However, none of the OPE metabolites was associated with ultra-processed food consumption in models adjusted for sociodemographic characteristics, health behaviors, and BMI (all p-values >0.05). Ultra-processed breads and tortillas; sauces, dressing, and gravies; and milk-based drinks were associated with higher concentrations of BDCPP while frozen and shelf-stable plate meals were associated with lower concentrations. Reconstituted meat or fish products and ultra-processed milk-based desserts were associated with greater odds of detectable levels of BCPP. While some food groups were associated with urinary OPE metabolite concentrations, ultra-processed foods do not appear to be a major source of current OPE exposure in the US.

Kim H ，Rebholz CM ，Wong E ，Buckley JP ... -  《-》

Predictors and reproducibility of urinary organophosphate ester metabolite concentrations during pregnancy and associations with birth outcomes in an urban population.

Kuiper JR ，Stapleton HM ，Wills-Karp M ，Wang X ，Burd I ，Buckley JP ... -  《Environmental Health》

Associations of Organophosphate Ester Flame Retardant Exposures during Pregnancy with Gestational Duration and Fetal Growth: The Environmental influences on Child Health Outcomes (ECHO) Program.

Oh J ，Buckley JP ，Li X ，Gachigi KK ，Kannan K ，Lyu W ，Ames JL ，Barrett ES ，Bastain TM ，Breton CV ，Buss C ，Croen LA ，Dunlop AL ，Ferrara A ，Ghassabian A ，Herbstman JB ，Hernandez-Castro I ，Hertz-Picciotto I ，Kahn LG ，Karagas MR ，Kuiper JR ，McEvoy CT ，Meeker JD ，Morello-Frosch R ，Padula AM ，Romano ME ，Sathyanarayana S ，Schantz S ，Schmidt RJ ，Simhan H ，Starling AP ，Tylavsky FA ，Volk HE ，Woodruff TJ ，Zhu Y ，Bennett DH ，program collaborators for Environmental influences on Child Health Outcomes ... -  《-》