New Mexico Geological Society Annual Spring Meeting — Abstracts

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Exposure to metal and metalloids poses serious health implications to human health, primarily through inhalation. Metal, nonmetal, and aggregate (MNM) mine workers are constantly exposed to dust particles generated through surface and underground mining operations. Prolonged exposure to respirable crystalline silica (RCS) is a major concern among miners, as it is linked to silicosis and other silica-related diseases. However, the chemical and physical nature of respirable MNM dust and their dissolution behavior in bodily fluid are poorly understood. In our recent work, we investigate physicochemical characteristics and toxicological effects of inhalable MNM dust to better understand how metal and metalloid leaching into lung fluids contribute to occupational health impacts on miners. This study investigates dust samples from four aggregate mines and one metal mine. The toxicity is further examined based on its geographic location and different particle size fractions. For each mine, respirable dust fractions (<10 mm) from drilling powder and loader material are prepared using a cascade impactor prior to the analysis. Samples were analyzed using a scanning electron microscope, Fourier Transform Infrared Spectroscopy, X-ray diffraction, and total microwave acid digestion, followed by Inductively coupled mass spectrometry to study the physicochemical characteristics. Bioleaching of toxic metals, metalloids, and nonmental fractions from respirable dust to body fluids is determined in batch reactor studies using various simulated lung fluids, including Gamble’s solution and artificial lysosomal fluid. Our results highlight significant amounts of dissolved Si, Al, Fe, Mn, Cu, Ti, and Fe in these body fluids, which correlates to the physicochemical characteristics of dust. The cell viability and immune responses upon exposure to inhalable mine dust are further evaluated using human lung tissue cells. The preliminary data suggests a notable impact of respirable dust on cell death and biological processes. These findings highlight crucial insights into the importance of site-specific risk assessments that focus on different geological locations and support the development of occupational health regulations to minimize the risks.