Background

Organophosphate esters (OPEs) have replaced flame retardant polybrominated diphenyl ethers as flame retardants in consumer products, but few longitudinal studies have characterized childhood OPE exposure.

Objective

We aimed to examine the exposure pattern of urinary OPE metabolites in children.

Methods

We quantified three urinary OPE metabolites five times in children (1, 2, 3, 5, 8 years) from 312 mother-child pairs in the Health Outcomes and Measures of the Environment (HOME) Study, a prospective pregnancy and birth cohort in Cincinnati, Ohio, USA. We examined the associations of average maternal OPE metabolite concentrations with OPE metabolite concentrations in childhood, characterized childhood OPE trajectories with latent class growth analysis (LCGA), and examined factors related to trajectory membership.

Results

Bis(2-chloroethyl) phosphate (BCEP) had the lowest median concentrations over time (0.66–0.97 mg/L) while the median concentrations of bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) increased with age (1.44–3.80 mg/L). The median concentrations of diphenyl phosphate (DPHP) fluctuated between 1.96 and 2.69 mg/L. Intraclass correlation coefficients for urinary metabolites measured at five time points indicated high variability within individuals (0.13–0.24). Average maternal urinary BCEP and BDCIPP were associated with concentrations in early childhood. Maternal education, the birth year of the child, and having a carpet in the main activity room were associated with BCEP and BDCIPP trajectory while none of the factors were associated with DPHP trajectory.

Significance

The trajectory analysis showed different patterns of urinary OPE metabolite concentrations, suggesting the need to collect multiple samples to adequately reflect OPE exposure.

Impact statement

In this well-established cohort, we evaluated the patterns of urinary OPE metabolites in children ages 1–8 years. The number of repeated measures over childhood has not been achieved in prior studies. Our results suggested the high variability of urinary OPE metabolites within individuals. Maternal metabolite concentrations during pregnancy were related to child concentrations at ages 1–3 years. BCEP, BDCIPP, and DPHP demonstrated different trajectories in children, which suggests that multiple samples may be required to capture OPE exposure patterns in childhood.

中文翻译：

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儿童尿有机磷酸酯代谢轨迹模式：HOME 研究

背景

有机磷酸酯 (OPE) 已取代阻燃剂多溴二苯醚作为消费品中的阻燃剂，但很少有纵向研究描述儿童 OPE 暴露的特征。

客观的

我们的目的是检查儿童尿液中 OPE 代谢物的暴露模式。

方法

在健康结果和环境测量 (HOME) 研究（辛辛那提的一项前瞻性妊娠和出生队列）中，我们对 312 对母子对的儿童（1、2、3、5、8 岁）中的三种尿液 OPE 代谢物进行了五次定量，美国俄亥俄州。我们研究了母亲平均 OPE 代谢物浓度与儿童时期 OPE 代谢物浓度的关联，通过潜在类别生长分析 (LCGA) 描述了儿童 OPE 轨迹，并检查了与轨迹成员资格相关的因素。

结果

随着时间的推移，磷酸二（2-氯乙基）酯（BCEP）的中位浓度最低（0.66-0.97 mg/L），而磷酸二（1,3-二氯-2-丙基）酯（BDCIPP）的中位浓度随着年龄的增长而增加（ 1.44–3.80 毫克/升）。磷酸二苯酯 (DPHP) 的中位浓度在 1.96 至 2.69 mg/L 之间波动。在五个时间点测量的尿液代谢物的组内相关系数表明个体内部存在较高的变异性（0.13-0.24）。平均母尿 BCEP 和 BDCIPP 与幼儿时期的浓度相关。母亲受教育程度、孩子的出生年份以及主要活动室是否铺有地毯与 BCEP 和 BDCIPP 轨迹相关，而这些因素均与 DPHP 轨迹无关。

意义

轨迹分析显示尿 OPE 代谢物浓度的不同模式，表明需要收集多个样本以充分反映 OPE 暴露。

影响报告

在这个成熟的队列中，我们评估了 1-8 岁儿童尿液 OPE 代谢物的模式。先前的研究尚未达到儿童期重复测量的次数。我们的结果表明个体内尿 OPE 代谢物存在高度变异性。怀孕期间母亲的代谢浓度与 1-3 岁时的儿童浓度相关。BCEP、BDCIPP 和 DPHP 在儿童中表现出不同的轨迹，这表明可能需要多个样本来捕获儿童时期的 OPE 暴露模式。