Department of Chemistry, Gulu University, P. O. Box 166, Gulu, Uganda; Department of Chemistry, Makerere University, P. O. Box 7062, Kampala, Uganda.
Helmholtz Zentrum Muenchen, German National Research Centre for Environmental Health (GmbH), Molecular EXposomics (MEX), Ingolstaedter Landstrasse 1, Neuherberg, Munich, Germany; School of Life Sciences Weihenstephan (Nutrition), Technische Universität München, 85354 Freising, Germany.
Sci Total Environ. 2021 May 20;770:145262. doi: 10.1016/j.scitotenv.2021.145262. Epub 2021 Jan 20.
Persistent organic pollutants (POPs) are ubiquitous contaminants with adverse health effects in the ecosystem. One of such effects is endocrine disruption in humans and wildlife even at background exposure concentrations. This study assessed maternal breastmilk concentrations of POPs; brominated flame retardants (BFRs), polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), and the potential health risks posed to the nursing infants. We also evaluated the association of these POPs with total 3,3',5-triiodo-L-thyronine (T), L-thyroxine (T), and 3,3',5'-triiodo-L-thyronine (rT) levels measured in human breast milk. Thirty breastmilk samples were collected from Kampala, Uganda between August and December 2018. Hexabromobenzene was not detected while the maximum level of 2,2',4,4',5,5'-hexabrombiphenyl was 64.7 pg/g lw. The median levels of total indicator PCBs, PBDEs, dioxin-like PCBs, and PCDD/Fs in the samples were 159 pg/g lw, 511 pg/g lw, 1.16 pg TEQ/g lw, and 0.4 pg TEQ/g lw, respectively. These levels were lower than those reported in other countries. Owing to their bio accumulative nature, PCBs -81, -169, and ∑PCDD/Fs increased with increase in maternal age. Estimated dietary intakes for dioxin-like PCBs and PCDD/Fs were lower than those reported elsewhere but were higher than the WHO tolerable daily intakes suggesting potential health risks to nursing infants. In adjusted single pollutant models, PCB-126, PCB-169, and ∑PCB were negatively associated with T, while 1,2,3,4,5,7,8-HpCDF was positively associated with rT. Although these associations did not persist in multipollutant models, our findings suggest potential thyroid hormone disruption by POPs in mothers. This may reduce the levels of thyroid hormones transferred from the mother to the neonates and, hence, adversely influence infant growth. A temporal study with a bigger sample size is required to corroborate these findings.
持久性有机污染物（POPs）是无处不在的污染物，对生态系统中的健康有不良影响。其中一种影响是即使在背景暴露浓度下，也会对人类和野生动物造成内分泌干扰。本研究评估了母体母乳中持久性有机污染物；溴化阻燃剂（BFRs）、多氯联苯（PCBs）和多氯二苯并对二恶英/呋喃（PCDD/Fs）的浓度，以及这些污染物对哺乳期婴儿构成的潜在健康风险。我们还评估了这些 POPs 与人类母乳中测量的总 3,3',5-三碘甲状腺原氨酸（T）、甲状腺素（T）和 3,3',5'-三碘甲状腺原氨酸（rT）水平之间的关系。2018 年 8 月至 12 月期间，从乌干达坎帕拉采集了 30 份母乳样本。未检测到六溴苯，而 2,2',4,4',5,5'-六溴联苯的最高水平为 64.7 pg/g lw。样本中总指示性 PCBs、PBDEs、二恶英样 PCBs 和 PCDD/Fs 的中位数水平分别为 159 pg/g lw、511 pg/g lw、1.16 pg TEQ/g lw 和 0.4 pg TEQ/g lw，这些水平低于其他国家报告的水平。由于其生物累积性质，随着母体年龄的增加，PCBs-81、-169 和∑PCDD/Fs 增加。二恶英样 PCBs 和 PCDD/Fs 的估计膳食摄入量低于其他地方报告的水平，但高于世界卫生组织可耐受每日摄入量，表明对哺乳期婴儿存在潜在健康风险。在调整后的单污染物模型中，PCB-126、PCB-169 和∑PCB 与 T 呈负相关，而 1,2,3,4,5,7,8-HpCDF 与 rT 呈正相关。尽管这些关联在多污染物模型中没有持续存在，但我们的研究结果表明，POPs 可能会破坏母亲的甲状腺激素。这可能会降低从母亲转移到新生儿的甲状腺激素水平，并因此对婴儿的生长产生不利影响。需要进行一项具有更大样本量的时间研究来证实这些发现。
