Dataset Information

Olivine Dissolution in Simulated Lung and Gastric Fluid as an Analog to the Behavior of Lunar Particulate Matter Inside the Human Respiratory and Gastrointestinal Systems.

ABSTRACT: With the Artemis III mission scheduled to land humans on the Moon in 2025, work must be done to understand the hazards lunar dust inhalation would pose to humans. In this study, San Carlos olivine was used as an analog of lunar olivine, a common component of lunar dust. Olivine was dissolved in a flow-through apparatus in both simulated lung fluid and 0.1 M HCl (simulated gastric fluid) over a period of approximately 2 weeks at physiological temperature, 37°C. Effluent samples were collected periodically and analyzed for pH, iron, silicon, and magnesium ion concentrations. The dissolution rate data derived from our measurements allow us to estimate that an inhaled 1.0 μm diameter olivine particle would take approximately 24 years to dissolve in the human lungs and approximately 3 weeks to dissolve in gastric fluid. Results revealed that inhaled olivine particles may generate the toxic chemical, hydroxyl radical, for up to 5-6 days in lung fluid. Olivine dissolved in 0.1 M HCl for 2 weeks transformed to an amorphous silica-rich solid plus the ferric iron oxy-hydroxide ferrihydrite. Olivine dissolved in simulated lung fluid shows no detectable change in composition or crystallinity. Equilibrium thermodynamic models indicate that olivine in the human lungs can precipitate secondary minerals with fibrous crystal structures that have the potential to induce detrimental health effects similar to asbestos exposure. Our work indicates that inhaled lunar dust containing olivine can settle in the human lungs for years and could induce long-term potential health effects like that of silicosis.

SUBMITTER: Hendrix DA

PROVIDER: S-EPMC8609536 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Air pollution is a major environmental health risk and it contributes to respiratory and cardiovascular diseases and excess mortality worldwide. The adverse health effects have been associated with the inhalation of fine particulate matter (PM2.5) and induction of respiratory oxidative stress. In this work, we quantified the oxidative potential (OP) of PM2.5 from several Canadian cities (Toronto, Hamilton, Montreal, Vancouver) using a recently developed bioanalytical method which measures the oxidation of lung antioxidants, glutathione, cysteine, and ascorbic acid, the formation of glutathione disulfide and cystine, and the related redox potential (RP) in a simulated epithelial lining fluid (SELF). We evaluated the application of empirical SELF RP as a new metric for aerosol OP. We further investigated how PM2.5 chemical composition and OP are related across various emission source sectors and whether these features are linked to specific properties of aerosol aqueous phase, such as pH and metal-ligand complexation. The OP indicators including SELF RP were strongly correlated among each other, indicating that the empirical RP could be used as a reliable metric in future studies. OP based on ascorbic acid showed dependency on the emission source sectors, most likely due to variation in the solubility of Fe. Traffic emissions resulted in the highest OP, followed by industrial emissions and resuspended crustal matter. OP presented low correlation with PM2.5 concentrations, low-moderate correlation with the aerosol organic matter, and moderate-strong association with black carbon and transition metals across the sites. We did not find strong association between the concentration of biomass burning tracers and OP. Copper was the only metal that showed high association with OP across all sites, whereas the correlation with other metals, such as iron, manganese, and titanium, showed clear dependency on the source sectors. The aerosol pH correlated negatively with ambient temperature and positively with biomass burning tracers and the levels of nitrate, ammonium, and aerosol liquid water content. The solubility of Fe was associated with sulfate and aerosol pH at most sites, suggesting the involvement of proton-mediated dissolution pathway, while this was not visible at the site influenced by industrial emission, most likely due to the abundance of pyrogenic Fe. The effect of metal-ligand complexation on the solubility of transition metals, in particular Fe, was clearly observed at all sites, whereas a combined effect with aerosol pH, and a subsequent impact on OP, was only seen at the traffic site in Toronto. The enhanced solubility of Fe due to proton- and ligand-mediated dissolution pathways and subsequent formation of reactive oxygen species may in part explain the health effects of PM2.5 seen in previous epidemiological studies.

Dataset Information

Olivine Dissolution in Simulated Lung and Gastric Fluid as an Analog to the Behavior of Lunar Particulate Matter Inside the Human Respiratory and Gastrointestinal Systems.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets