Thirty-nine groundwater samples were collected from wells near the Tavan Tolgoi and Oyu Tolgoi mines in Mongolia and at a relatively pristine site in northern Mongolia during August to September 2013, and analyzed for the concentrations of F, NO, Hg, As, Al, V, Mn, Co, Ni, Cu, Zn, Se, Mo, Cd, Sb, and Pb. A probabilistic risk assessment found that >95% of the population in the areas was at risk from drinking well water. The hazard index (HI) was >1, indicating a non-carcinogenic risk to human health. At Oyu Tolgoi, the hazard quotient (HQ) of the As concentration (mean 6.63 μg/L) was >1. At the northern site, the 95th percentile HQ was <1 but the 95th percentile HI was >1. The ratios of nitrogen and oxygen stable isotopes indicated that NO contamination of groundwater at Oyu Tolgoi and Tavan Tolgoi was caused by livestock waste. Mercury accumulation in livestock was examined from concentrations in livestock forage and in hair and wool samples from livestock in the South Gobi region. Sheep wool had the same level of mercury as in Japan, but camel, horse, and goat hair had high levels.
A foehn wind is an important factor in the occurrence of many extreme high-temperature events in geographically complex regions. In this study, the authors verified the hypothesis that a foehnlike wind contributes to high temperatures at the end of the leeward (eastward) area using three difference approaches: field experiments, numerical experiments, and statistical analyses. According to the hypothesis, a foehnlike wind has the features of the sum of a traditional foehn effect with adiabatic heating, plus dry-diabatic heating from the ground surface along the fetch of the wind. Field experiments conducted at seven observational points on Nobi Plain, Japan, where a mesoscale westerly wind blew, revealed that the westerly wind clearly had the features of a traditional foehn effect in the western part of the Nobi Plain. In addition to field experiments, a simplified estimate using a simple mixed-layer model demonstrated that the wind was further heated by dry-diabatic heating (sensible heat supply) from the ground surface along the fetch (especially in urbanized areas in the eastern region of the Nobi Plain) of the wind. This diabatic heating effect along the fetch of the wind on the high temperature at the end of the leeward area was also supported by both additional numerical experiments and a statistical analysis. These results proved that the hypothesis is correct and indicated that ground conditions and the land use and land cover in the windward area were strongly related to air temperature at the end of the leeward area, where an extremely high temperature was observed.
To achieve the elemental characterization of particles emitted from the aircraft, we performed elemental analysis using micro-PIXE for those emitted from carbon disc brakes and tires in addition to the turbine blade particles and engine reverser particles of the exhaust produced by jet engines, and identified the characteristics of individual particles from the elemental maps. As for the elemental characteristics of aircraft source particles, the turbine blade particles contained 16 elements (Na, Mg, Al, Si, S, K, Ca, Se, Ti, Cr, Mn, Fe, Co, Ni, Cu and W), and were considered to be those of the same origin. In the case of the engine reverser particles, in addition to turbine blade particles and turbine blade wear particles (nickel alloy), atmospheric particles were found. As one hypothesis, particles containing Ti–V, Mn–W and Cu–Zn may have got altered or aggregated in the process of particles moving from the turbine blade to the engine reverser. Clumps of particles were exhibited only in the elemental maps of tire particles. These clumps of particles were shaped like they had been scraped away, and were believed to have been caused by friction between the tire and the runway. These results aid in determining the component features of particles emitted from an aircraft.
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