Distribution Characteristics of Rare Earth Elements in Children's Scalp Hair from a Rare Earths Mining Area in Southern China

Abstract

In order to demonstrate the validity of using scalp hair rare earth elements (REEs) content as a biomarker of human REEs exposure, data were collected on REEs exposure levels from children aged 11–15 years old and living in an ion-adsorptive type light REEs (LREEs) mining and surrounding areas in southern China. Sixty scalp hair samples were analyzed by ICP-MS for 16 REEs (La–Lu, Y and Sc). Sixteen REEs contents in the samples from the mining area (e.g., range: La: 0.14–6.93 µg/g; Nd: 0.09–5.27 µg/g; Gd: 12.2–645.6 ng/g; Lu: 0.2–13.3 ng/g; Y: 0.03–1.27 µg/g; Sc: 0.05–0.30 µg/g) were significantly higher than those from the reference area (range: La: 0.04–0.40 µg/g; Nd: 0.04–0.32 µg/g; Gd: 8.3–64.6 ng/g; Lu: 0.4–3.3 ng/g; Y: 0.03–0.29 µg/g; Sc: 0.11–0.36 µg/g) and even much higher than those published in the literature. The distribution pattern of REEs in scalp hair from the mining area was very similar to that of REEs in the mine and the atmosphere shrouding that area. In conclusion, the scalp hair REEs contents may indicate not only quantitatively but also qualitatively (distribution pattern) the absorption of REEs from environmental exposure into human body. The children living in this mining area should be regarded as a high-risk group with REEs (especially LREEs) exposure, and their health status should be examined from a REEs health risk assessment perspective.

Keywords:

• Scalp hair
• Rare earth elements
• Lanthanide
• Scandium
• Yttrium
• Exposure assessment
• Biomarker

Acknowledgments

The authors express their gratitude to Prof. Li Tianlin and Prof. Liu Junzhuo (Peking University, Public Health School), Prof. Zhang Qi and associate Prof. Shen Lipu (Geological Research Institute, Chinese Academy of Sciences) for their valuable suggestions on this article. We also owe special thanks to Prof. Zhang Qi and associate Prof. Shen Lipu for their technical instructions on the methodology for study on REEs distribution pattern, to Prof. Yang Yueqing and Prof. Bai Ge (Mineral Resource Research Institute, Geology Mineral Resource Ministry) for their valuable geological information.