Inhalation of dust generated in the mining process exposes workers to many health hazards. The inorganic elements nickel, copper, arsenic, cadmium, and lead have been found in some mine ore and have suspected relationships to adverse health effects. Dissolution rates for copper, arsenic, lead, cadmium, and nickel in respirable sized particles of a selected mine ore were determined in synthetic lung fluid at two different pH levels.Synthetic lung fluid with a pH of 7.2 was used to simulate extracellular lung fluid and synthetic lung fluid with a pH of 4.5 was used to simulate intracellular lung fluid. The synthetic lung fluid samples and quality assurance and quality control samples were continuously agitated for a 25-day period. A ten-milliliter sample was removed from each solution on days 0, 1, 2, 3, 4, 5, 6, 7, 10, 14, 18, 21, and 25. Each sample was analyzed for dissolved nickel, copper, arsenic, cadmium, and lead concentrations using inductively coupled plasma mass spectrometry.Analytical results show that all inorganic elements investigated dissolved at a higher rate in the 4.5 pH synthetic lung fluid than in the 7.2 pH synthetic lung fluid throughout the 25-day sampling period. In summary, it was observed that the dissolution rates for all inorganic elements in synthetic lung fluid were significantly different in the solutions at the two different pH levels. Maximum concentration of each inorganic element was higher in the 4.5 pH synthetic lung fluid solution.Results of this study show the five inorganic elements investigated are more likely to dissolve in intracellular lung fluid than in extracellular lung fluid. © 2014 Division of Chemical Health and Safety of the American Chemical Society.