Jursa Thomas, Stein Cheryl R, Smith Donald R
Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA 95064, USA.
Department of Child and Adolescent Psychiatry, Hassenfeld Children's Hospital at NYU Langone, Child Study Center, New York University, New York, NY 10016, USA.
Toxics. 2018 Mar 22;6(2):19. doi: 10.3390/toxics6020019.
Biomarkers of environmental metal exposure in children are important for elucidating exposure and health risk. While exposure biomarkers for As, Cd, and Pb are relatively well defined, there are not yet well-validated biomarkers of Mn exposure. Here, we measured hair Mn, Pb, Cd, and As levels in children from the Mid-Ohio Valley to determine within and between-subject predictors of hair metal levels. Occipital scalp hair was collected in 2009-2010 from 222 children aged 6-12 years (169 female, 53 male) participating in a study of chemical exposure and neurodevelopment in an industrial region of the Mid-Ohio Valley. Hair samples from females were divided into three two centimeter segments, while males provided a single segment. Hair was cleaned and processed in a trace metal clean laboratory, and analyzed for As, Cd, Mn, and Pb by magnetic sector inductively coupled plasma mass spectrometry. Hair Mn and Pb levels were comparable (median 0.11 and 0.15 µg/g, respectively) and were ~10-fold higher than hair Cd and As levels (0.007 and 0.018 µg/g, respectively). Hair metal levels were higher in males compared to females, and varied by ~100-1000-fold between all subjects, and substantially less (<40-70%) between segments within female subjects. Hair Mn, Pb, and Cd, but not As levels systematically increased by ~40-70% from the proximal to distal hair segments of females. There was a significant effect of season of hair sample collection on hair Mn, Pb, and Cd, but not As levels. Finally, hair metal levels reported here are ~2 to >10-fold lower than levels reported in other studies in children, most likely because of more rigorous hair cleaning methodology used in the present study, leading to lower levels of unresolved exogenous metal contamination of hair.
儿童环境金属暴露生物标志物对于阐明暴露情况和健康风险至关重要。虽然砷、镉和铅的暴露生物标志物相对明确，但锰暴露的生物标志物尚未得到充分验证。在此，我们测量了俄亥俄州中部山谷地区儿童头发中的锰、铅、镉和砷水平，以确定个体内和个体间头发金属水平的预测因素。2009年至2010年，从参与俄亥俄州中部山谷工业区化学暴露与神经发育研究的222名6至12岁儿童（169名女性，53名男性）中收集枕部头皮头发。女性的头发样本被分成三个两厘米长的段，而男性提供一个段。头发在痕量金属清洁实验室进行清洗和处理，并通过磁扇形电感耦合等离子体质谱法分析砷、镉、锰和铅。头发中的锰和铅水平相当（中位数分别为0.11和0.15微克/克），比头发中的镉和砷水平高约10倍（分别为0.007和0.018微克/克）。男性的头发金属水平高于女性，所有受试者之间的差异约为100至1000倍，而女性受试者不同段之间的差异则小得多（<40-70%）。女性头发从近端到远端段，锰、铅和镉（但砷水平未）系统地增加了约40-70%。头发样本采集季节对头发中的锰、铅和镉水平有显著影响，但对砷水平无影响。最后，此处报告的头发金属水平比其他儿童研究中报告的水平低约2至>10倍，这很可能是因为本研究采用了更严格的头发清洗方法，导致头发中未解决的外源性金属污染水平较低。
