An x-ray fluorescence technique to measure the mercury burden of dentists in vivo

Abstract

Hg exposure in dental offices may represent a health hazard. Previous studies evaluated Hg exposure through blood, urine or hair analysis. Hg content of body fluids in hair depended on the time since Hg exposure, mode of intake and excretion, and sequestration by different tissues. Utilizing an X-ray fluorescence [XRF] technique, the Hg burden in bone, liver, lung, spleen and kidney was measured in vitro. XRF and chemical assays of Hg content of these samples correlated. XRF technique was used to assay Hg content of tissues irradiated in vivo. Hg signal arising at a depth in tissue was reduced as the thickness of overlying material increased. XRF assay for tissues in vivo was confined to organs near the surface. Hg content of the superficial layers of the head and wrist were determined in situ for a dental population. Concentrations as low as 20 .mu.g/g were detected with an exposure of 60 mR. Of 298 dentists evaluated, 28% had > 20 .mu.g/g Hg in the head.