Rendón-Lugo A N, Santiago P, Puente-Lee I, León-Paniagua L
Museo de Zoología "Alfonso L. Herrera", Facultad de Ciencias, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, A. P. 70-399, D. F, 04510, Coyoacán, Mexico.
Instituto de Física, UNAM, Mexico City, Mexico.
Environ Monit Assess. 2017 Nov 18;189(12):640. doi: 10.1007/s10661-017-6338-z.
The capacity of mammal hair to absorb toxic metals and its utility in biomonitoring has been broadly studied. Though these metal-binding properties has generally been attributed to the sulphur contained in cysteine, an amino acid that forms part of keratin, there are not many experimental studies that analyze the role of sulphur in the external deposition of potentially toxic metallic elements in order to better understand the potential of hair in biomonitoring and generate better tools for differentiating between internal and external deposition of contaminants. In this study, an experimental analysis is carried out using a scanning electron microscope on hairs of five terrestrial mammal species (Peromyscus furvus, P. maniculatus, Glossophaga soricina, Artibeus jamaicensis and Marmosa mexicana) treated with cadmium, copper and lead salts. We quantified absorbed metals as well as natural elements of the hair by energy dispersive X-ray spectroscopy (EDS) to analyze using simple statistics the role of sulphur in the absorption Cd, Cu and Pb. Given the lack of studies comparing the mechanisms of deposition of metal elements among different orders of Class Mammalia, external morphology was considered to be an important factor in the deposition of metallic particles of Cd, Cu and Pb. Bat species (Glossophaga soricina, Artibeus jamaicensis) showed a high concentration of particles in their scales, however, no between-species differences in metal absorption were observed, and during the exogenous deposition metal particles do not permeate the medulla. These results suggest that the sulphur in hair itself cannot bind metals to hair cuticle and that hair absorption capacity depends on a variety of factors such as aspects of hair morphology.
哺乳动物毛发吸收有毒金属的能力及其在生物监测中的作用已得到广泛研究。尽管这些金属结合特性通常归因于半胱氨酸中所含的硫，半胱氨酸是构成角蛋白的一种氨基酸，但为了更好地理解毛发在生物监测中的潜力并开发出更好的工具来区分污染物的内部和外部沉积，分析硫在潜在有毒金属元素外部沉积中的作用的实验研究并不多。在本研究中，使用扫描电子显微镜对用镉、铜和铅盐处理过的五种陆生哺乳动物（暗色鹿鼠、北美鹿鼠、长吻长舌蝠、 Jamaican 果蝠和墨西哥棉鼠）的毛发进行了实验分析。我们通过能量色散X射线光谱法（EDS）对吸收的金属以及毛发中的天然元素进行了定量，以便用简单的统计方法分析硫在镉、铜和铅吸收中的作用。鉴于缺乏比较哺乳动物不同目之间金属元素沉积机制的研究，外部形态被认为是镉、铜和铅金属颗粒沉积的一个重要因素。蝙蝠物种（长吻长舌蝠、Jamaican果蝠）的鳞片中显示出高浓度的颗粒，然而，未观察到物种间金属吸收的差异，并且在外部沉积过程中金属颗粒不会渗透到髓质中。这些结果表明，毛发本身的硫不能将金属结合到毛小皮上，并且毛发的吸收能力取决于多种因素，如毛发形态方面的因素。
