Background

Use of organophosphate flame retardants (OPFRs) including tris(1,3-dichloro-2-propyl) phosphate, triphenyl phosphate, tris(1-chloro-2-propyl) phosphate, and tris-2-chloroethyl phosphate, in consumer products is on the rise because of the recent phase out of polybrominated diphenyl ether (PBDE) flame retardants. Some of these chemicals are also used as plasticizers or lubricants in many consumer products.

Objectives

To assess human exposure to these chlorinated and non-chlorinated organophosphates, and non-PBDE brominated chemicals in a representative sample of the U.S. general population 6 years and older from the 2013–2014 National Health and Nutrition Examination Survey (NHANES).

Methods

We used solid-phase extraction coupled to isotope dilution high-performance liquid chromatography-tandem mass spectrometry after enzymatic hydrolysis of conjugates to analyze 2666 NHANES urine samples for nine biomarkers: diphenyl phosphate (DPHP), bis(1,3-dichloro-2-propyl) phosphate (BDCIPP), bis-(1-chloro-2-propyl) phosphate (BCIPP), bis-2-chloroethyl phosphate (BCEP), di-n-butyl phosphate (DNBP), di-p-cresylphosphate (DpCP), di-o-cresylphosphate (DoCP), dibenzyl phosphate (DBzP), and 2,3,4,5-tetrabromobenzoic acid (TBBA). We calculated the geometric mean (GM) and distribution percentiles for the urinary concentrations (both in micrograms per liter [μg/L] and in micrograms per gram of creatinine). We only calculated GMs for analytes with an overall weighted frequency of detection > 60%. For those analytes, we also a) determined weighted Pearson correlations among the log10-transformed concentrations, and b) used regression models to evaluate associations of various demographic parameters with urinary concentrations of these biomarkers.

Results

We detected BDCIPP and DPHP in approximately 92% of study participants, BCEP in 89%, DNBP in 81%, and BCIPP in 61%. By contrast, we detected the other biomarkers much less frequently: DpCP (13%), DoCP (0.1%), TBBA (5%), and did not detect DBzP in any of the participants. Concentration ranges were highest for DPHP (< 0.16–193 μg/L), BDCIPP (< 0.11–169 μg/L), and BCEP (< 0.08–110 μg/L). Regardless of race/ethnicity, 6–11 year old children had significantly higher BCEP adjusted GMs than other age groups. Females had significantly higher DPHP and BDCIPP adjusted GM than males, and were more likely than males to have DPHP concentrations above the 95th percentile (odds ratio = 3.61; 95% confidence interval, 2.01–6.48).

Conclusions

Our results confirm findings from previous studies suggesting human exposure to OPFRs, and demonstrate, for the first time, widespread exposure to several OPFRs among a representative sample of the U.S. general population 6 years of age and older. The observed differences in concentrations of certain OPFRs biomarkers by race/ethnicity, in children compared to other age groups, and in females compared to males may reflect differences in lifestyle and exposure patterns. These NHANES data can be used to stablish a nationally representative baseline of exposures to OPFRs and when combined with future 2-year survey data, to evaluate exposure trends.

中文翻译：

---

美国普通人群接触有机磷酸酯阻燃化学品的情况：来自 2013-2014 年国家健康和营养检查调查的数据

 背景

消费产品中使用的有机磷酸酯阻燃剂 (OPFR) 包括磷酸三(1,3-二氯-2-丙基)酯、磷酸三苯酯、磷酸三(1-氯-2-丙基)酯和磷酸三-2-氯乙酯由于最近逐步淘汰多溴二苯醚 (PBDE) 阻燃剂，这一趋势正在上升。其中一些化学品还在许多消费品中用作增塑剂或润滑剂。

 目标

旨在评估 2013-2014 年国家健康和营养检查调查 (NHANES) 中 6 岁及以上美国普通人群的代表性样本中人类对这些氯化和非氯化有机磷酸盐以及非 PBDE 溴化化学品的暴露情况。

 方法

我们在酶解缀合物后使用固相萃取结合同位素稀释高效液相色谱-串联质谱分析 2666 个 NHANES 尿液样本中的 9 种生物标志物：磷酸二苯酯 (DPHP)、双(1,3-二氯-2-磷酸二（1-氯-2-丙基）酯（BDCIPP）、磷酸二（1-氯-2-丙基）酯（BCIPP）、磷酸二-2-氯乙酯（BCEP）、磷酸二正丁酯（DNBP）、磷酸二对甲苯酯（DpCP） )、磷酸二邻甲苯酯(DoCP)、磷酸二苄酯 (DBzP) 和 2,3,4,5-四溴苯甲酸 (TBBA)。我们计算了尿浓度的几何平均值 (GM) 和分布百分位数（均以微克每升 [μg/L] 和微克每克肌酐为单位）。我们仅计算总体加权检测频率为 >60% 的分析物的 GM。对于这些分析物，我们还 a) 确定了 log10 转换浓度之间的加权皮尔逊相关性，b) 使用回归模型来评估各种人口统计参数与这些生物标志物尿浓度的关联。

 结果

我们在大约 92% 的研究参与者中检测到 BDCIPP 和 DPHP，89% 的参与者检测到 BCEP，81% 的参与者检测到 DNBP，61% 的参与者检测到 BCIPP。相比之下，我们检测到其他生物标志物的频率要低得多：DpCP (13%)、DoCP (0.1%)、TBBA (5%)，并且没有在任何参与者中检测到 DBzP。 DPHP (<0.16–193μg/L)、BDCIPP (<0.11–169μg/L) 和 BCEP (<0.08–110μg/L) 的浓度范围最高。无论种族/民族如何，6-11 岁儿童的 BCEP 调整后 GM 显着高于其他年龄组。女性的 DPHP 和 BDCIPP 调整后 GM 显着高于男性，并且比男性更有可能 DPHP 浓度高于第 95 个百分位数（比值比 = 3.61；95% 置信区间，2.01-6.48）。

 结论

我们的结果证实了先前研究的结果，表明人类暴露于 OPFR，并首次证明在 6 岁及以上美国普通人群的代表性样本中广泛暴露于多种 OPFR。观察到的某些 OPFR 生物标志物浓度因种族/民族、儿童与其他年龄组以及女性与男性相比的差异可能反映了生活方式和暴露模式的差异。这些 NHANES 数据可用于建立具有全国代表性的 OPFR 暴露基线，并与未来 2 年调查数据相结合，以评估暴露趋势。