Seminar: In Vivo Bone Lead Measurements Of Tibia and Index Phalanx Bones Using Portable X-ray Fluorescence

Student: Fatima Hajir

Supervisor: Dr. Ana Pejovic-Milic

Abstract

Lead (Pb) is a toxic heavy metal that accumulates in the human body and poses serious health risks through both acute and chronic exposure. While blood lead levels are the standard biomarker for recent exposure, bone lead serves as a critical indicator of long-term cumulative exposure. This study investigates In vivo bone lead measurements using portable X-ray fluorescence (L-XRF) technology, comparing the tibia and proximal phalanx of the index finger as cortical bone sites. The L-XRF system, specifically the Thermo Scientific Niton XL5 Plus, offers a low-dose, portable, and non-invasive approach for real-time Pb analysis in occupational and non-occupational populations. A novel build-up correction calibration method developed by Sajed Mcheik is also evaluated to enhance measurement accuracy. It is hypothesized that the thinner soft tissue over the phalanx bone will improve sensitivity for detecting bone lead. This research aims to assess the homogeneity of Pb distribution in bone, validate new calibration methods, and contribute toward establishing a portable diagnostic tool for long term Pb exposure assessment in Ontario.