Rebelo Fernanda Maciel, Caldas Eloisa Dutra
Brazilian Health Surveillance Agency, University of Brasilia, 70910-900 Brasilia, DF, Brazil.
Laboratory of Toxicology, Department of Pharmacy, University of Brasilia, 70910-900 Brasilia, DF, Brazil.
Environ Res. 2016 Nov;151:671-688. doi: 10.1016/j.envres.2016.08.027. Epub 2016 Sep 10.
Metals are ubiquitous in nature, being found in all environmental compartments, and have a variety of applications in human activities. Metals are transferred by maternal blood to the fetus via the placenta, and exposure continues throughout life. For the general population, exposure comes mainly from water and food consumption, including breast milk. In this paper, we reviewed studies on the toxicity of arsenic, lead, mercury and cadmium, the toxic metals of most concern to human health, focusing on the potential risks to newborns and infants. A total of 75 studies published since 2000 reporting the levels of these metals in breast milk were reviewed. Lead was the metal most investigated in breast milk (43 studies), and for which the highest levels were reported (up to 1515µg/L). Arsenic was the least investigated (18 studies), with higher levels reported for breast milk (up to 149µg/L) collected in regions with high arsenic concentrations in water (>10µg/L). Data from 34 studies on mercury showed that levels in breast milk were generally higher in populations with high fish consumption, where it may be present mainly as MeHg. Cadmium levels in breast milk were the lowest, with means <2µg/L in most of the 29 studies reviewed. Results of risk assessments indicated that the intake of arsenic, lead and mercury by infants through breastfeeding can be considered a health concern in most regions of the world. Although the potential risks to infants are mostly outweighed by the benefits of breast milk consumption, it is essential that contaminants be continuously monitored, especially in the most critical regions, and that measures be implemented by health authorities to reduce exposure of newborns and infants to these metals, and thus avoid unnecessary health risks.
金属在自然界中无处不在，存在于所有环境介质中，并且在人类活动中有多种应用。金属通过母体血液经胎盘传递给胎儿，且终生都存在暴露风险。对于普通人群而言，暴露主要来自饮水和食物摄入，包括母乳。在本文中，我们综述了有关砷、铅、汞和镉这几种对人类健康最为关注的有毒金属毒性的研究，重点关注对新生儿和婴儿的潜在风险。我们查阅了自2000年以来发表的75项报告母乳中这些金属含量的研究。铅是母乳中研究最多的金属（43项研究），报告的含量也最高（高达1515微克/升）。砷的研究最少（18项研究），在水中砷浓度较高（>10微克/升）的地区收集的母乳中报告的含量较高（高达149微克/升）。34项关于汞的研究数据表明，在鱼类消费量高的人群中，母乳中的汞含量通常较高，汞在其中可能主要以甲基汞的形式存在。母乳中的镉含量最低，在 reviewed的29项研究中，大多数研究的平均值<2微克/升。风险评估结果表明，在世界大多数地区，婴儿通过母乳喂养摄入砷、铅和汞可被视为对健康的一种担忧。尽管母乳喂养的益处大多超过了对婴儿的潜在风险，但持续监测污染物至关重要，尤其是在最关键的地区，卫生当局应采取措施减少新生儿和婴儿接触这些金属，从而避免不必要的健康风险。
