Quantitative Assessment of the Size-dependent Whole-body to Cellular Biodistribution of Fine Particulate Matters Following Inhalation by Fluorescence Imaging

Background: There has been growing concern regarding the impact of air pollution, especially fine dust, on human health. However, it is difficult to estimate the toxicity of fine dust on the human body because of its diverse effects depending on the composition and environmental factors.Results: In this study, we focused on the difference in the biodistribution of fine dust according to the size distribution of particulate matter after inhalation into the body to predict its impact on human health. We synthesized Cy7-doped silica particulate matters (CSPMs) having different particle sizes and employed them as model fine dust, and studied their whole-body in vivo biodistribution in BALB/c nude mice. Image-tracking and quantitative analysis were performed on the ex vivo organs and tissues. Additionally, flow cytometric analysis of single cells isolated from the lungs was performed. Smaller particles with a diameter of less than 100 nm (CSPM0.1) were observed to be removed relatively rapidly from the lungs upon initial inhalation. However, they were confirmed to accumulate continuously over 4 weeks of observation. In particular, smaller particles were found to spread rapidly to other organs during the early stages of inhalation.Conclusions: It is expected that the effect of fine dust on human health can be predicted through the differences in in vivo behavior that arise depending on the particle size. This study might provide with insights on association between CSPM0.1 accumulation in several organs including the lungs and adverse effect to underlying diseases in the organs.

Sustainable Electrochemical NO Capture and Storage System Based on the Reversible Fe2+/Fe3+-EDTA Redox Reaction

The removal of nitric oxide (NO), which is an aggregation agent for fine dust that causes air pollution, from exhaust gas has been considered an important treatment in the context of environmental conservation. Herein, we propose a sustainable electrochemical NO removal system based on the reversible Fe2+/Fe3+-ethylenediamine tetraacetic acid (EDTA) redox reaction, which enables continuous NO capture and storage at ambient temperature without the addition of any sacrificial agents. We have designed a flow-type reaction system in which the NO absorption and emission can be separately conducted in the individual reservoirs of the catholyte and anolyte with the continuous regeneration of Fe2+-EDTA by the electrochemical reduction in Fe3+-EDTA. A continuous flow reaction using a silver cathode and glassy carbon anode showed that the concentrations of Fe2+ and Fe3+-EDTA in the electrolyte were successfully maintained at a 1:1 ratio, which demonstrates that the proposed system can be applied for continuous NO capture and storage.

Analysis of the Factors Affecting Fine Dust Concentration Before and After COVID-19

This study conducted a comparative analysis of the factors affecting the concentration of fine dust before and after COVID-19. Of these, the dominant factor was CO, and the influence between variables increased even after COVID-19. In the case of PM10, the influence of wind direction and wind speed variables decreased, which is thought to be due to the reduction of westerly-based foreign air pollutants following China’s containment policy. Comparative analysis by season showed that the influence of temperature and humidity was higher in winter. In spring, the influence of wind direction and speed decreased with changes in the westerly wind and the influence of China’s containment policy. In summer and autumn, when the concentration of fine dust is relatively low, the influence of CO after COVID-19 was rather high, indicating that continuous CO management is necessary. Considering the relationship between these air pollutants and the meteorological environment, it is judged that fine dust reduction measures should be implemented.

Attention to News Media, Emotional Responses, and Policy Preferences about Public Health Crisis: The Case of Fine Dust Pollution in South Korea

This study examines how attention to science and political news may influence the way people feel about an environmental risk, and how this in turn impacts policy preferences. Using an online survey conducted on the issue of fine dust pollution in South Korea, this study found that science news attention was associated with greater anxiety and anger about the issue, whereas political news attention was associated with fear and sadness/depression (as well as anxiety and anger). Furthermore, mediation analysis showed that science news attention indirectly influenced support for preventive policy through anxiety, whereas political news attention indirectly influenced punitive policy support through anger and fear. Theoretical and practical implications of this study are discussed.

Groove Formation on Metal Substrates by Nanosecond Laser Removal of Melted Material

An effective strategy to produce grooves on carbon steel substrates by nanosecond laser radiation is proposed. The aim is to increase the productivity of grooves creation. In this study, two different modes of laser treatment are compared. The first mode focuses on the evaporation of material, while the second focuses on the formation of melted material and its removal by the action of pressure vapors produced by evaporated material. Within some ranges of processing parameters, the shape of the groove can be linearly controlled. The dependence of the groove depth also has a logarithmic nature when the number of passes is increased. Using the liquid phase mode in some ranges of parameters can reduce the amount of evaporated material in comparison with standard techniques in which the material is removed in the form of gas, and fine dust is emitted.