Exposure to Non-exhaust Emission in Central Seoul using an Agent-based Framework

Non-exhaust emission (NEE) from brake and tyre wear cause deleterious effects on human health, but the relationship with mobility has not been thoroughly examined. We construct an in silico agent-based traffic simulator for Central Seoul to illustrate the coupled problems of emissions, behaviour, and the estimated exposure to PM10 (particles less than 10 microns in size) for groups of drivers and subway commuters. The results show that significant extra particulates relative to the background exist along roadways where NEEs contributed some 40% of the roadside PM10. In terms of health risk, 88% of resident drivers had an acute health effect in late March but that kind of emergence rarely happened. By contrast, subway commuters’ health risk peaked at a maximum of 30% with frequent oscillations whenever the air pollution episodes occurred. A 90% vehicle restriction scenario reduced PM10 by 18-24%, and reduced the resident driver's risk by a factor of 2, but not effective for subway commuters as the group generally walked through background areas rather than along major roadways. Using an agent-based traffic simulator in a health context can give insights into how exposure and health outcomes can depend on the time of exposure and the mode of transport.

Multi-Objective Optimisation of Tyre and Suspension Parameters during Cornering for Different Road Roughness Profiles

Effective emission control technologies and novel propulsion systems have been developed for road vehicles, decreasing exhaust particle emissions. However, work has to be done on non-exhaust traffic related sources such as tyre–road interaction and tyre wear. Given that both are inevitable in road vehicles, efforts for assessing and minimising tyre wear should be considered. The amount of tyre wear is because of internal (tyre structure, manufacturing, etc.) and external (suspension configuration, speed, road surface, etc.) factors. In this work, the emphasis is on the optimisation of such parameters for minimising tyre wear, but also enhancing occupant’s comfort and improving vehicle handling. In addition to the search for the optimum parameters, the optimisation is also used as a tool to identify and highlight potential trade-offs between the objectives and the various design parameters. Hence, initially, the tyre design (based on some chosen tyre parameters) is optimised with regards to the above-mentioned objectives, for a vehicle while cornering over both Class A and B road roughness profiles. Afterwards, an optimal solution is sought between the Pareto alternatives provided by the two road cases, in order for the tyre wear levels to be less affected under different road profiles. Therefore, it is required that the tyre parameters are as close possible and that they provide similar tyre wear in both road cases. Then, the identified tyre design is adopted and the optimum suspension design is sought for the two road cases for both passive and semi-active suspension types. From the results, significant conclusions regarding how tyre wear behaves with regards to passenger comfort and vehicle handling are extracted, while the results illustrate where the optimum suspension and tyre parameters have converged trying to compromise among the above objectives under different road types and how suspension types, passive and semi-active, could compromise among all of them more optimally.

MO015ANALYZING THE EFFECT OF MICROPLASTIC PARTICLES ON HUMAN PODOCYTES

Background and Aims Despite increasing use of plastic based products and their potential health risks on the humans, very little is known about their possible accumulation in the food chain and their further long-term effect on the human health. Recently, there are increasing reports related to the potential risk of polystyrene microplastics to the human respiratory system and human intestinal epithelia cell line. In this study, we assayed the primary effect of microplastic particles on the human kidney cells. To that aim, we used human podocytes cells and four different types of plastic particles including; polyvinyl chloride (PVC), polypropylene (PP), polyamide (PA) and tyre wear particles to evaluate the effects of microplastics on the viability and morphology of human podocytes in vitro. Method In this study, we applied different biological methods such as, cell viability test and phalloidin staining, to assay the toxicity of particles and their further effects on the actin cytoskeleton organization in human podocytes, respectively. Furthermore, Raman imaging is used to track particle attachment on the cells and to evaluate the possible changes in the cell compartment following the particle treatment. The particle uptake by the cells and changes in cellular biological features were visualized with the use of scanning electron microscopy (SEM). Results As a primary result, the cytotoxicity response of particle treatment was found to be dependent on the polymer type. As an example higher concentration of PP particle as compared to PVC, PA, and tyre wear caused a similar rate of cell mortality. Furthermore, the degree of particle attachment on the cells depended on their adhesion properties, which was higher in PA, PVC and tyre wear in comparison to PP particles. These particles remained attached to the cell surface even after two-three times of washing with PBS. Based on the phalloidin staining results, particle treatment induced cytoskeleton reorganization in podocytes in vitro. With the use of Raman imaging particle attachment was confirmed based on the fingerprint spectra related to each particle. Conclusion This study suggests that exposure duration and particle concentrations are two of the key factors to evaluate the toxicological effect of particles on podocytes as a highly-specialized epithelial cells in the kidney. It is supposed that two mechanisms can be related to the harmful effects of plastic particles on podocytes. First, particle attachment on the cell surface leading to limitation of nutrient uptake by the cells. Second, uptake of smaller size particles into the cells through phagocytosis. More studies are necessary to determine the direct effect of microplastics on human kidney cells.

Multielement Contamination of Land in the Margin of Highways

The spatial distribution of potentially toxic elements in land near a heavily loaded highway in the West Attica region (Greece) is discussed. This study aimed to investigate the extent of soil contamination with trace elements on land in the margin of highways. The concentration of thirty-five elements in topsoil, car ash, and road sediment bulk samples was determined. Statistical and spatial analysis was applied for evaluating the geochemical dispersion of the examined elements. Geo-accumulation index was estimated. Elements content were compared to criteria and screening values established by the literature. The concentration of As, Cu, Mn, Ni, P, Pb, and Zn in topsoil appeared to be influenced by traffic emissions. It is found that engine exhaust, tyre wear, and brake lining contribute to the As, Ba, Cu, Mn, Ni, P, Pb, and Zn content recorded in topsoil in the margin of highways. The bulk sample of road sediment is moderately contaminated to extremely contaminated with Cu, Mn, Ni, P, Pb, and Zn. Comparison of elements content in topsoil with screening values revealed that Al, As, B, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Sb, V, and Zn pose a potential risk for plants.