Localization of vanadium-containing particles in the lungs of uranium/vanadium miners

Abstract

Several geological formations of the Utah-Colorado mining region mined for uranium ore during and after World War II had been mined earlier for vanadium. Therefore, most miners and millers from that region were exposed to those metals' ores or tailings at one time or another. Preliminary investigation to determine uranium and vanadium retained in the lungs of a former uranium miner and miller from this region, who died of lung cancer (mesothelioma), showed a high nonuniform distribution of vanadium. This observation led to the hypothesis that the vanadium content in the lungs could be associated with inhaled particles. Further examination of spectra of characteristic X-rays obtained by scanning particle-induced X-ray emission (microPIXE) of an autopsy sample of this lung indicated that vanadium was indeed present in localized sites within the 20-μm spatial resolution of the proton beam. This work points out that the microPIXE-RBS (Rutherford backscattering) test for vanadium can be used for site localization of inhaled particles retained in the lungs. Further studies are in progress to: (i) locate uranium-bearing particles in lung tissues of former uranium miners and millers; and (ii) evaluate the local doses of alpha radiation received from these particles.

Toxicity of Vanadium Compounds: Pulmonary and Immune System Targets

“…Differences in how V particles are handled in the lung are best reflected by clearance or retention patterns (see //, 12,13). Inhaled insoluble V 2 0 5 particles localize in AM phagosomes after ingestion and undergo a slow dissolution to vanadate ions.…”

“…However, after 24 hr, the two forms diverge in ability to be cleared, with V 2 0 5 persisting (9). Thus, absorption of V compounds (50-85% of an inhaled dose) vary as a function of solubility; total V clearance is never achieved and commonly 1-3% of an original dose can persist for extended periods (i.e., months->years) (4,10,11,12). Though inhalation is the primary means of delivery of V into the lungs, exposure by other routes also leads to increased lung V burden and toxic manifestations (13,14).…”