School of Public Health, Division of Environmental Health Sciences, University of Minnesota, Minneapolis, MN, 55455, USA.
Medical School and Department of Pediatrics, Division of Neonatology, University of Minnesota, Minneapolis, MN, 55454, USA.
Sci Rep. 2018 Nov 19;8(1):17034. doi: 10.1038/s41598-018-35112-0.
Elevated in utero and early childhood exposure to manganese may have adverse effects on neurodevelopment. We conducted preliminary analyses to evaluate toenails as a matrix for investigating manganese exposure in infants. Infant and maternal toenail and hair samples were collected from 25 infants (7 months old) and their mothers. A subset of mothers was recruited in the third trimester of pregnancy and some also provided pre-natal toenail, hair, and blood samples, cord blood, and additional post-natal samples. Collected samples were analyzed by inductively coupled plasma mass-spectrometry. Toenail manganese levels in infants ranged from below the limit of detection (LOD) to 2.80 µg/g. Only 1 toenail sample and 4 hair samples contained levels of manganese below LOD. Associations between infant and maternal biomarkers were not statistically significant. Analysis of multiple post-natal toenail samples from a single infant-mother pair showed an increase in the infant's toenail manganese and a decrease in maternal toenail manganese over the first year of the infant's life. Overall, our findings suggest that toenails may serve as a valuable biological matrix for measuring manganese exposure in newborns and infants; however, additional studies are needed to determine the impact of the timing of toenail sample collection on its utility in assessing early life exposure and health outcomes.
胎儿期和幼儿期暴露于高水平的锰可能对神经发育有不良影响。我们进行了初步分析，以评估指甲作为研究婴儿锰暴露的基质。从 25 名 7 个月大的婴儿及其母亲身上采集了婴儿和母亲的指甲和头发样本。一部分母亲在妊娠晚期被招募，其中一些人还提供了产前指甲、头发和血液样本、脐血以及其他产后样本。采集的样本通过电感耦合等离子体质谱法进行分析。婴儿指甲中的锰含量从检测限（LOD）以下到 2.80μg/g 不等。只有 1 个指甲样本和 4 个头发样本的锰含量低于 LOD。婴儿和母亲的生物标志物之间没有统计学上的显著关联。对来自单个婴儿-母亲对的多个产后指甲样本的分析表明，在婴儿生命的第一年，婴儿指甲中的锰含量增加，而母亲指甲中的锰含量减少。总的来说，我们的研究结果表明，指甲可能是测量新生儿和婴儿锰暴露的有价值的生物基质；然而，需要进一步的研究来确定指甲样本采集时间对评估早期生活暴露和健康结果的影响。
