Laser Ablation ICP-MS: Human hair as a biomarker for methylmercury elimination rate
Collaborators: The Rand Lab at the University of Rochester
Methylmercury (MeHg) exposure from the consumption of fish is a public health concern. Individual variation in response to MeHg exposure and the rate of MeHg biotransformation complicates our understanding of this issue. MeHg elimination from the human body occurs slowly (approximately 70 days half-life [t1/2]) and is a major determinant of the Hg body burden resulting from fish consumption. The mechanisms that control MeHg elimination from the human body are poorly understood. We developed methods to determine MeHg elimination rate via spatial Hg analysis of hair using laser ablation-inductively coupled plasma-mass spectrometry. Hair specimens were collected from participants in a controlled feeding study. Ablating the hair every 333 µm gave a daily measure of Hg body burden during the process of elimination from the body.
Image of a human hair showing the ablation sites.
Screenshot showing the ablation signals of Hg and S along the length of human hair, and on the right, a hair strand mid-ablation
This approach has been validated to show that, after MeHg exposure – for example from consuming fish – changes in hair Hg concentration parallel changes in blood Hg concentration.
Using LA-ICP-MS to measure Hg concentrations from the hair tip to the root, the controlled exposures from the three individual fish meals can be seen (green arrows), as well as progressive elimination of Hg from the body.