Movement around real and virtual cluttered environments

Two experiments investigated participants’ ability to search for targets in a cluttered small-scale space. The first experiment was conducted in the real world with two field of view conditions (full vs. restricted), and participants found the task trivial to perform in both. The second experiment used the same search task but was conducted in a desktop virtual environment (VE), and investigated two movement interfaces and two visual scene conditions. Participants restricted to forward only movement performed the search task quicker and more efficiently (visiting fewer targets) than those who used an interface that allowed more flexible movement (forward, backward, left, right, and diagonal). Also, participants using a high fidelity visual scene performed the task significantly quicker and more efficiently than those who used a low fidelity scene. The performance differences between all the conditions decreased with practice, but the performance of the best VE group approached that of the real-world participants. These results indicate the importance of using high fidelity scenes in VEs, and suggest that the use of a simple control system is sufficient for maintaining ones spatial orientation during searching

Movement around real and virtual cluttered environments

Two experiments investigated participants’ ability to search for targets in a cluttered small-scale space. The first experiment was conducted in the real world with two field of view conditions (full vs. restricted), and participants found the task trivial to perform in both. The second experiment used the same search task but was conducted in a desktop virtual environment (VE), and investigated two movement interfaces and two visual scene conditions. Participants restricted to forward only movement performed the search task quicker and more efficiently (visiting fewer targets) than those who used an interface that allowed more flexible movement (forward, backward, left, right, and diagonal). Also, participants using a high fidelity visual scene performed the task significantly quicker and more efficiently than those who used a low fidelity scene. The performance differences between all the conditions decreased with practice, but the performance of the best VE group approached that of the real-world participants. These results indicate the importance of using high fidelity scenes in VEs, and suggest that the use of a simple control system is sufficient for maintaining ones spatial orientation during searching

Air Pollution Costs in Ukraine

The paper presents estimation of the health losses from urban air pollution in Ukraine. The methodology developed by US EPA and adjusted in Russia for Eastern European transition countries was applied for health risk assessment. PM2.5 was identified as the major source of human health risk, based on experience from the Russian studies. In the absence of reliable computed concentrations of PM2.5, the study was based on monitoring data of total suspended particle (TSP) emissions in Ukraine. Additional cases of mortality and morbidity were calculated based on reporting data on TSP concentration that was recalculated into PM2.5. Then the concentration–response function was applied to estimate individual risk. Next, individual risk was applied to the population exposed to the concentration reported for each city included in the analysis (we selected most polluted cities). For each city we considered individual data on baseline mortality and morbidity and population structure. In total, air pollution related mortality represents about 6 percent of total mortality in Ukraine. In Russia the corresponding indicator totals about 4 percent. The relative mortality risk attributed to air pollution calculated per 100 000 population in both countries is about 55-59 cases. Since applied method is sensitive to the primary data uncertainties we conducted sensitivity analysis applying Monte-Carlo method. Economic damage related to mortality risk was estimated at about 4 percent of GDP. There was no relevant WTP study in Ukraine therefore we applied the benefit-transfer method in order to estimate VSL, since mortality attributed to air pollution is major component of health losses (about 94 percent). In order to compare and aggregate mortality and morbidity risks we recalculated them in DALY. Then morbidity represents about 30 percent of total air pollution health load. Data on baseline morbidity is less reliable than data on baseline mortality; therefore the morbidity risk estimates are more uncertain than mortality estimates. It is likely that morbidity risk is underestimated. Regardless of uncertainties mentioned above and some problems with reported data we can conclude that the mortality risk attributed to air pollution is significant. Therefore, costs of air pollution in Ukraine are sizable and in the nearest future may offset the economic growth. Recovery of the Ukrainian economy based on restoration of polluting industries may lead to stagnation since mortality and morbidity risks not only puts burden on the economy, but also reduce labor force.Air Pollution, Ukraine, Environmental Damages

Valuing the health impacts from particulate air pollution in Tianjin

Although China has made dramatic economic progress in recent years, air pollution continues to be the most visible environmental problem and imposes significant health and economic costs on society. Using data on pollutant concentration and population for 2003, this paper estimates the economic costs of health related effects due to particulate air pollution in urban areas of Tianjin, China. Exposure-response functions are used to quantify the impact on human health. Value of a statistical life and benefit transfer are used to obtain the unit value of some health effects. Our results show significant health costs associated with air pollution in Tianjin. The total economic cost is estimated to be US$1.1 billion, about 3.7% of Tianjin’s GDP in 2003. The findings underscore the importance of urban air pollution control. Finally, the policy implications for alternative energy options and climate policies are given.particulate air pollution, PM10, economic valuation, Tianjin