Trace Toxic Elements

The main focus of my research is the development of biomedical devices based on radiation physics techniques for the in vivo measurement of trace toxic elements. In the last few years, my graduate students have built the first in vivo systems in the world for the painless, non-invasive and low dose measurement of arsenic, gadolinium and fluoride. We use two main techniques for these devices; neutron activation analysis (NAA) and x-ray fluorescence (XRF) analysis.

In addition to building biomedical systems, I apply them to studies of human health and exposure. My research has helped the understanding of human health effects from lead (Pb) exposure; my work has shown that Pb can result in elevated blood pressure and early menopause in women. Recently we discovered that people living in Hamilton have measurable levels of fluoride in their bones and a major source of exposure is tea drinking. We have been studying gadolinium and this element is used in image enhancement drugs for MRI. The Gd may be detaching from the chelate which could be potentially toxic, so we are developing systems to measure long term uptake of detached Gd in bone.

Some of the reasons I study toxic metals are explained in the Research2Reality video which can be found at http://research2reality.com/video-categories/health/ under ‘measuring health effects of metal exposure’.

Radiation Tools in Cultural Heritage

In recent years, I have used radiation tools in the study of art and cultural heritage. I was a member of a team who studied nine works of art from the McMaster Museum of Art. This resulted in an exhibition, The Unvarnished Truth: Exploring the Material History of Paintings, which is travelling across Canada until 2017. The work is also presented in the interactive website http://theunvarnishedtruth.mcmaster.ca/ .

Low Dose Radiation Effects

For the last few years, I have been collaborating with Professors Colin Seymour and Carmel Mothersill from the Department of Biology. We have been studying the effects of low level exposure to radiation types that include x- and γ-rays and neutrons. We have recently shown that cells, when exposed to radiation, emit a UV signal which can cause effects in nearby cells that were not exposed to the initial radiation. The UV causes a ‘halo’ of effect. We are continuing to explore whether this UV signaling is an important aspect of low dose radiation effects.

Development of radiation-based biomedical devices for the painless, in vivo measurement of toxic metals such as Pb, As, F, Al and Gd in bone, liver, and kidney.