A preliminary risk assessment of potential exposure to naturally occurring estrogens from Beijing (China) market milk products

This study was conducted to determine the occurrence of the natural steroid hormones estrone (El), 17 alpha-estradiol (alpha E2), 17 beta-estradiol (beta E2) and estriol (E3) in 38 commercial milk samples obtained from markets in Beijing, China. Liquid Chromatography coupled with tandem mass spectrometry (LC-MS/MS) was employed to determine estrogens levels. The concentrations of El, alpha E2, beta E2 and E3 in different milk products varied from 0-146.12 ng/L, 0-70.12 ng/L, 0-31.85 ng/L to 0-2.18 ng/L, respectively. We compared exposures to estrogens through milk consumption with acceptable daily intakes (ADIs) and threshold for toxicological concern (TTC) to determine whether estrogen intakes from milk consumption are larger or smaller than the toxicity-based benchmarks. The combined margin of safety MOS (MOST) for total estrogens are about 72-99, 118-161, 539-1104, for 2-4, 4-7 year-old residential children, and adults, respectively. The lowest MOST for children of 2-4 years old result from comparing total of estrogens with the lowest TTC value (0.15 mu g/person/day) (MOS = 3.5). The MOS values suggest that the individual and total estrogens that may present in milk are not causing a health risk for the local residents, including young children. (C) 2014 Elsevier Ltd. All rights reserved.

本研究旨在确定在中国北京市场获取的38份商业牛奶样品中天然类固醇激素雌酮（E1）、17α - 雌二醇（αE2）、17β - 雌二醇（βE2）和雌三醇（E3）的存在情况。采用液相色谱 - 串联质谱法（LC - MS/MS）测定雌激素水平。不同奶制品中E1、αE2、βE2和E3的浓度分别在0 - 146.12纳克/升、0 - 70.12纳克/升、0 - 31.85纳克/升和0 - 2.18纳克/升之间变化。我们将通过饮用牛奶摄入雌激素的量与每日可接受摄入量（ADIs）以及毒理学关注阈值（TTC）进行比较，以确定通过饮用牛奶摄入的雌激素量是大于还是小于基于毒性的基准值。总雌激素的综合安全边际（MOS，MOST）对于2 - 4岁、4 - 7岁的儿童以及成年人分别约为72 - 99、118 - 161、539 - 1104。2 - 4岁儿童的最低MOS是通过将总雌激素量与最低TTC值（0.15微克/人/天）进行比较得出的（MOS = 3.5）。MOS值表明，牛奶中可能存在的单一雌激素和总雌激素不会对当地居民（包括幼儿）造成健康风险。（C）2014爱思唯尔有限公司。保留所有权利。