David Chettle - Physics & Astronomy

David Chettle

Title:

Professor Emeritus

Office:

NRB-106

Phone:

27340

Email:

...

Measuring the Elemental Composition of the Human Body

Soo-Hyun Byun in position for a neutron activation measurement of his hand. We develop and use techniques based in atomic and nuclear physics for non destructive elemental analysis of bulk samples. Specifically, we use x-ray fluorescence and neutron activation analysis with the aim of finding out the elemental content of living human subjects. I work closely with Fiona McNeill on many of these projects and we both collaborate with Soo-Hyun Byun, particularly drawing on his expertise in nuclear instrumentation and pulse processing. These measurements involve ionising radiation (photons or neutrons) so a key preliminary to any proposed measurement is to ensure that the dose is acceptably low, typically well within the range employed by established medical diagnostic procedures.

The most widely applied of our techniques is the analysis of lead in bone using x-ray fluorescence. In this we collaborate with industry, with academic colleagues in the US and, in a study headed by Fiona McNeill, with Health Canada. Our work has contributed to a change in thinking about long term lead exposure, particularly highlighting the importance of endogenous exposure, that is what happens when lead stored over time in bone is released back into the body via the blood.

In another example, we recently completed a pilot study, using neutron activation to Exceptionally high lead levels in the skull of a person who had suffered from Paget’s Disease. measure aluminum in bone of a group of people suffering from Alzheimer’s Disease and a comparison group with no signs of dementia.

Strontium seems to be ambiguous with regards to bone health. In excess it causes a rickets-like condition. However, people suffering from osteoporosis administered a strontium supplement had fewer fractures than a comparison group. We have developed an x-ray fluorescence method to measure strontium in bone and we are seeking to find ways (and funding!) to use this further in exploring the interaction of strontium with bone health.

Strontium being measured in a finger bone. I have a strong interest in the interaction between science and faith from the perspective of an activate participant in both communities. With colleagues I help to run the Hamilton Science and Faith Forum, the local chapter of the Canadian Scientific and Christian Affiliation.

Research Interests:

Non invasive elemental analysis of the human body; x-ray fluorescence; neutron activation analysis

Dear Highly Qualified Person in Training,

You may be an undergraduate seeking summer research experience, about to enter graduate school to pursue your masters, or looking to enter doctoral research. Alternatively, maybe you are just finishing your PhD and now wish to move forward, perhaps broadening your horizons. I have had the pleasure of working with people growing their skills and experience at many levels. Although it must be admitted that my ability to recruit will always depend on having sufficient funding.

A glance at my Research Profile will show you that I like to measure things, in particular elements in living human subjects. This means that a person working with me is likely to be involved in one specific project. This can be early stage assessment of the feasibility of analysing an element not previously assessed non invasively in humans. Or it may involve refining a technique to make it applicable to a wider range of subjects. It could mean becoming involved in a survey of human subjects.

So far, 20 people who worked with me have successfully completed their PhDs (8 at the University of Birmingham, UK and 12 here at McMaster). By the time you read this, one or two more may well have joined this group. In part, of course, this just says that I’ve been around quite a while and I’m now old! I’m attracted by the model of graduate student-supervisor interaction as colleagues, albeit one being more experienced. I’d like to think that is how it works out in our group. You can probably identify my former students, because it is their names that are first on the majority of “my” publications.

My capacity to recruit will depend on the result of research proposals for which we’re awaiting the outcome. Do feel free to contact me if you would like more information.

Regards,

David Chettle.

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