铅锌矿区居民头发中Pb、Fe、Cu、Zn元素的SRXRF微区分布分析与来源分析

SRXRF elemental mapping and source analysis of Pb,Fe,Cu and Zn in human hair from an inhabitant in a lead-zinc mining area

人发中元素的微区分布与结合特征分析可为矿山环境污染与人体健康关系研究提供新证据。用同步辐射X射线荧光微区分析技术研究南京栖霞山铅锌矿区居民头发元素微区分布特征,头发毛囊根部的Pb相对强度较低,远离根部发干中Pb相对强度较高,具有与持续环境暴露相关的纵向累积特征;Fe、Cu、Zn纵向相对强度分布较稳定。发干皮质组织中Pb、Fe、Cu、Zn相对强度较高,表皮组织中Pb、Fe、Cu相对强度较低,但无Zn,髓质组织中Cu、Zn相对强度比皮质组织中稍低,Pb和Fe未检出。依据元素在头发中的分布特征,认为外源性污染来源的Pb构成居民发Pb的主要来源,Fe、Cu、Zn为内源性生理代谢来源,Cu和Zn参与了头发发育的整个生理代谢过程。在生物地球化学微小样品分析领域,同步辐射X射线荧光微区分析技术成为一门重要的分析手段。

Elemental mapping of human hair may gain new insights for studying effects of mining environmental pollution on human health.SRXRF micro-analyses were conducted for longitudinal and transversal mapping of Pb,Fe,Cu and Zn relative intensities in hair sample collected from an inhabitant in Qixia lead-zinc mining area,Nanjing,Jiangsu province,China.The Pb relative intensity was low in hair follicle and root,but it increased with the hair growth.The longitudinal Pb accumulation in the hair shaft revealed a strong dependence on continuous exposure to the environment,while Fe,Cu and Zn relative intensities in the hair shaft were comparatively stable.The cortical proteins contributed to a high retention of Pb,Fe,Cu and Zn,while small quantities of all the elements but Zn were distributed in the cuticle.Medullar proteins were confirmed to contribute to slightly lower retention of Zn and Cu than cortical,but Pb and Fe were not detected in medulla.The sources of Pb in the hair were mostly exogenous contamination,and Fe,Cu and Zn were related to endogenous uptake.Zn and Cu participated in the entire metabolic process of hair growth.The study shows that SRXRF is of significance for biogeochemistry research.