Kempson Ivan M, Skinner William M
Ian Wark Research Institute, University of South Australia, Mawson Lakes 5095, Australia.
Sci Total Environ. 2005 Feb 15;338(3):213-27. doi: 10.1016/j.scitotenv.2004.07.017.
Elemental distributions on whole and longitudinal sections of hairs plucked from the scalp were studied with the surface sensitive technique time-of-flight secondary ion mass spectrometry (ToF-SIMS). Endogenous and environmental influences on the distributions of elemental species were identified. The cuticle scales appear to play the major role in the accumulation of exogenous products. The functionality of the outer surfaces and scale edges each preferentially bind different elemental species. The majority of elements considered accumulated longitudinally on the outer surface of the hair above the scalp level. Internally, most elemental signals (especially Al) decreased longitudinally once exposed to the environment with the exception of Si, which showed an increase. Images of elemental distributions within the medulla suggest that regions of different reactivity exist and show a variable ability to accumulate elemental species. The greatest signal intensities were observed in the cuticle and medulla regions rather than the cortex. The cuticle is continually exposed to environmental contamination and the medulla may, or may not, exist in a hair. Therefore, the components of a hair that potentially contribute the most to the elemental concentrations (i.e. the cuticle and medulla) are also the most variable, and as such greatly complicate the interpretation of elemental concentrations in hair. Results also suggest that bleaching hair can enhance the accumulation of contaminants.
采用表面敏感技术飞行时间二次离子质谱（ToF-SIMS）研究了从头皮拔出的毛发的整体和纵向切片上的元素分布。确定了内源性和环境因素对元素种类分布的影响。角质层鳞片似乎在外源产物的积累中起主要作用。外表面和鳞片边缘的功能各自优先结合不同的元素种类。大多数所考虑的元素在头皮水平以上的毛发外表面纵向积累。在内部，除了硅显示增加外，大多数元素信号（尤其是铝）一旦暴露于环境中就会纵向减少。髓质内元素分布的图像表明存在不同反应性的区域，并显示出积累元素种类的可变能力。在角质层和髓质区域观察到的信号强度最大，而不是皮质。角质层不断暴露于环境污染中，并且髓质可能存在于毛发中，也可能不存在。因此，对元素浓度潜在贡献最大的毛发成分（即角质层和髓质）也是最可变的，因此极大地复杂化了毛发中元素浓度的解释。结果还表明，漂白头发可以增强污染物的积累。
