Nicholas School of Environment, Duke University, Durham, NC, United States; Children's Health & Discovery Initiative, Duke School of Medicine, North Carolina, United States.
Nicholas School of Environment, Duke University, Durham, NC, United States.
Environ Int. 2020 Oct;143:106009. doi: 10.1016/j.envint.2020.106009. Epub 2020 Aug 6.
Organophosphate esters (OPEs) are applied as both flame retardants and plasticizers to a variety of consumer items such as home furnishings, construction materials, and children's products. While some assessments have characterized exposure among toddlers and young children, little is known about the OPE exposure among infants, who are a vulnerable population due to their rapid development. Here, we collected spot urine samples from 6-week-old (n = 100) and 12-month-old infants (n = 63), with about half of the infants evaluated at both ages (n = 52), to characterize OPE exposure and determine what factors contributed to higher exposures. Five of six OPE metabolites analyzed were detected frequently (>70%). Diphenyl phosphate was detected in every urine sample, while bis(2-chloro-isopropyl) phosphate (BCIPP) was the most abundant metabolite measured overall. Concentrations of bis(1-chloro-2-propyl) 1-hydroxy-2-propyl phosphate (BCIPHIPP) and BCIPP [i.e., metabolites of tris(2-chloro-isopropyl) phosphate (TCIPP)] were significantly greater among 6-week-old infants compared to 12-month-olds, while levels of other OPE metabolites were not statistically different in the first year of life. OPE metabolites were generally correlated with one another in samples collected at each age (r = 0.25-0.75; p < 0.05), and except BCIPHIPP, concentrations of the same metabolite were correlated over time (r = 0.41-0.53; p < 0.05). Breastfeeding at 6 weeks of age and owning a larger number of children's products were associated with increased concentrations of urinary BDCIPP. Infants who were currently receiving breast milk had higher levels of TCIPP metabolites; urinary BCIPP concentrations were 6.2 times higher in infants receiving breast milk at 6 weeks of age, and BCIPHIPP levels were 2.2 times higher for 12-month-old infants receiving breast milk (10 = 7.2; 95% CI: 1.6-32.1 and 10 = 3.2; 95% CI: 1.2-8.1, respectively). Differences in the predominant TCIPP metabolite associated with breastfeeding may suggest differences in metabolism with age. Cumulatively, our results suggest levels of OPE exposure may be higher for infants than other age groups, including toddlers and older children.
有机磷酸酯 (OPE) 既可用作阻燃剂，也可用作增塑剂，广泛应用于各种消费品，如家具、建筑材料和儿童产品。尽管一些评估已经确定了幼儿和儿童的接触情况，但对于婴儿的 OPE 接触情况却知之甚少，由于婴儿发育迅速，他们是一个脆弱的群体。在这里，我们收集了 6 周大（n=100）和 12 个月大（n=63）婴儿的尿样，其中约有一半的婴儿在两个年龄段都进行了评估（n=52），以描述 OPE 暴露情况，并确定哪些因素导致了更高的暴露水平。在所分析的六种 OPE 代谢物中，有五种经常被检测到（>70%）。二苯磷酸酯存在于每个尿液样本中，而双（2-氯异丙基）磷酸酯（BCIPP）是所有代谢物中含量最高的。6 周大的婴儿体内双（1-氯-2-丙基）1-羟基-2-丙基磷酸酯（BCIPHIPP）和 BCIPP（即三（2-氯异丙基）磷酸酯（TCIPP）的代谢物）的浓度明显高于 12 个月大的婴儿，而在生命的第一年，其他 OPE 代谢物的水平在统计学上没有差异。在每个年龄段收集的样本中，OPE 代谢物彼此之间通常呈正相关（r=0.25-0.75；p<0.05），除 BCIPHIPP 外，同一代谢物的浓度随时间呈正相关（r=0.41-0.53；p<0.05）。6 周大时母乳喂养和拥有更多儿童产品与尿液 BDCIPP 浓度升高有关。正在接受母乳喂养的婴儿 TCIPP 代谢物水平较高；6 周大时接受母乳喂养的婴儿 TCIPP 代谢物水平高出 6.2 倍，12 个月大时接受母乳喂养的婴儿 BCIPHIPP 水平高出 2.2 倍（10=7.2；95%CI：1.6-32.1 和 10=3.2；95%CI：1.2-8.1）。与母乳喂养相关的主要 TCIPP 代谢物的差异可能表明代谢随年龄的变化。总的来说，我们的结果表明，婴儿的 OPE 暴露水平可能高于其他年龄段，包括幼儿和大龄儿童。
