Institute of Environmental Studies, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, 113-0033, Tokyo, Japan.
Environ Health Prev Med. 2004 Jan;9(1):22-6. doi: 10.1265/ehpm.9.22.
Concerns over dietary exposure to bisphenol A (BPA), an endocrine disruptor, have been raised because BPA is contained in resins and plastics commonly used for the preservation of food and beverages. The purpose of the present study was to assess daily intake levels of BPA in a group of male subjects by measuring total urinary BPA (free BPA plus BPA released by treatment with β-glucuronidase), as well as determining intra-individual variation in BPA excretion.
Twenty-four-hour urine was collected from 5 subjects for 5 consecutive days for the evaluation of between-day variation in urinary BPA excretion and from 36 male subjects for the estimation of the level of daily BPA intake. BPA in the urine samples was measured by GC/MS/MS following enzymatic hydrolysis of BPA glucuronate, solid phase extraction, and derivatization.
A large between-day variation was found over 5 days for the daily excretion of urinary BPA in the 5 subjects. The daily excretion of urinary BPA was distributed log-normally in the 36 male subjects, with the median value being 1.2 μg/day (range: <0.21-14 μg/day), which was far below the Tolerable Daily Intake (0.01 mg/kg bw) recommended by a scientific committee in the European Commission in 2002. However, the maximum estimated intake per body weight (0.2 μg/kg/day) was only one order of magnitude lower than the reported lowest level for reproductive/behavioral effects in pregnant mice (2 μg/kg/day).
Measuring urinary BPA in urine is a suitable approach for estimating short-term BPA intake levels in individuals and/or estimating the average exposure level of populations. Urine analyses will be increasingly important in the human health risk assessment of BPA.
由于双酚 A（BPA）是一种内分泌干扰物，存在于用于保存食品和饮料的树脂和塑料中，因此人们对其通过饮食摄入产生了担忧。本研究的目的是通过测量总尿 BPA（游离 BPA 加上经β-葡糖苷酸酶处理释放的 BPA）来评估一组男性受试者的 BPA 日摄入量水平，并确定 BPA 排泄的个体内变异。
连续 5 天收集 5 名受试者的 24 小时尿液，以评估尿 BPA 排泄的日内变异性，并从 36 名男性受试者中估算每日 BPA 摄入量水平。尿液样品中的 BPA 经酶水解 BPA 葡糖苷酸、固相萃取和衍生化后，用 GC/MS/MS 进行测定。
5 名受试者连续 5 天的尿中 BPA 日排泄量存在较大的日内变异性。36 名男性受试者的尿中 BPA 日排泄量呈对数正态分布，中位数为 1.2 μg/天（范围：<0.21-14 μg/天），远低于欧洲委员会科学委员会在 2002 年推荐的可耐受日摄入量（0.01 mg/kg bw）。然而，按体质量估计的最大摄入量（0.2 μg/kg/天）仅比报告的怀孕小鼠生殖/行为效应的最低水平（2 μg/kg/天）低一个数量级。
测量尿中 BPA 是评估个体短期 BPA 摄入量水平和/或估计人群平均暴露水平的合适方法。尿液分析将在 BPA 的人类健康风险评估中变得越来越重要。
