In vivo measurement of arsenic, aluminum, indium and fluorine

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Mining and smelting are extremely important to the Canadian economy. Canada exported $48 billion worth of non-fuel minerals and mineral products in 2000 and is the world's largest producer of uranium, the third largest producer of copper, and produces zinc, lead, cadmium, platinum, indium, aluminum, gold... The economic dependence on this industry means that there are large numbers of Canadian workers exposed to potentially toxic elements and many Canadians exposed environmentally at lower levels.  Workers who are known to be exposed are generally monitored by their employer via blood and urine measurements. Workers whose levels increase above certain pre-set limits will be removed from potentially high exposure situations until their levels fall. However, measurement of blood or urine alone does not allow exogenous and endogenous exposures to be separately accounted for, and this can make the interpretation of risk complicated. It also makes the management of workers with extensive employment histories difficult, as they often have body stores of the element which can keep blood and urines elevated even in the absence of external exposure.  In addition, members of the public are not routinely monitored for their exposure. If exposure to a toxic element is suspected, blood and urine measurements can be performed. However, these usually only indicate recent exposure whereas the exposure may have taken place months or years prior  to the health consequence, and many health effects are a result of chronic or cumulative exposure. Biopsies can be taken to add further information, but these are uncomfortable at best, and may not be representative of the level within a whole organ. There is therefore a role in health management for techniques which can non-invasively measure in vivo the level of a toxic element either in organs at risk or in organs where the element is stored.The aim of this proposal is to develop physics techniques for the non-invasive in vivo measurement of four elements; arsenic, indium, aluminum and fluorine. Three techniques will be employed; x-ray fluorescence (XRF), neutron activation analysis (NAA) and Nuclear Magnetic Resonance (NMR).