Sources of productive efficiency: International comparison of iron and steel firms

Using a time-varying stochastic frontier model, this paper examines the technical efficiency of firms in the iron and steel industry to try to identify the factors contributing to the industry's efficiency growth. Industry observers and policymakers tend to cite most frequently three possible sources of efficiency growth: privatization; economies of scale; and vintage of equipment. Our study corroborates these factors. Based on our findings, which pertain to 52 iron and steel firms over the period of 1978–1997, privatization is likely to improve the efficiency of iron and steel firms to a great extent as evidenced in various industries. This study also provides systematic evidence that iron and steel production shows economies of scale. In addition, newer vintages of equipment are found to be closely correlated with higher levels of efficiency. This clearly indicates that investment in new plants and equipments is critical in pursuit of efficiency in the iron and steel industry.     

Public expectations about access fees and road closures on public lands

It is sometimes suggested that land managers could better communicate with the general public by relying on people who are active in community affairs to frame the message. By comparing responses from the ‘attentive’ and general public on the Colorado Plateau in the USA, this study investigated the expected effects of using recreation access fees or road closures to manage recreation on public lands. Although neither the attentive nor general public strongly anticipated benefits from the two management options, the attentive public was more likely than the general public to report positive expectations. Those more likely to expect fewer benefits from the management options do so because of factors that are outside the influence of managers (e.g., socio-demographics and value orientation). The results point out challenges for building public support through mobilizing the attentive public to develop a positive management atmosphere with fees and road closures.     

Contamination by Cd, Cu, Pb, and Zn in mine wastes from abandoned metal mines classified as mineralization types in Korea

The objective of this study was to investigate heavy metal contamination and geochemical characteristics of mine wastes, including tailings, from 38 abandoned mines classified as five mineralization types. Mine waste materials including tailings and soils were sampled from the mines and the physical and chemical characteristics of the samples were analyzed. The particle size of tailings was in the range of 10–100 μm. The pH of the waste covered a wide range, from 1.73 to 8.11, and was influenced by associated minerals and elevated levels of Cd, Cu, Pb, and Zn, extracted by a Korean Standard Method (digestion with 0.1 mol L⁻¹ HCl), which were found in the wastes. Half of the samples contained heavy metals at levels above those stipulated by the Soil Environmental Conservation Act (SECA) in Korea. In addition, extremely high concentrations of the metals were also found in mine wastes extracted by aqua regia, especially those from mines associated with sulfide minerals. Thus, it can be expected that trace elements in mine wastes may be dispersed both downstream and downslope through water and wind. Eventually they may pose a potential health risk to residents in the vicinity of the mine. It is necessary to control mine wastes by using a proper method for their reclamation, such as neutralization of the mine wastes using a fine-grained limestone.     

Human health risk assessment of explosives and heavy metals at a military gunnery range

In this research, a risk assessment was undertaken in order to develop the remediation and management strategy of a contaminated gunnery site, where a nearby flood controlling reservoir is under construction. Six chemicals, including explosives and heavy metals, posing potential risk to environmental and human health, were targeted in this study. A site-specific conceptual site model was constructed, based on effective, reasonable exposure pathways, to avoid any overestimation of the risk. Also, conservative default values were adapted to prevent underestimation of the risk when site-specific values were not available. The risks posed by the six contaminants were calculated using the API’s Decision Support System for Exposure and Risk Assessment, with several assumptions. In the crater-formed-area (Ac), the non-carcinogenic risks (i.e., HI values) of tri-nitro-toluene (TNT) and Cd were slightly larger than 1, but for RDX (Royal Demolition Explosives) was over 50. The total non-carcinogenic risk of the whole gunnery range was calculated to be 62.5, which was a significantly high value. The carcinogenicity of Cd was estimated to be about 10⁻³, while that for Pb was about 5 × 10⁻⁴, which greatly exceeded the generally acceptable carcinogenic risk level of 10⁻⁴–10⁻⁶. It was concluded from the risk assessment that there is an immediate need for remediation of both carcinogens and non-carcinogens before construction of the reservoir. However, for a more accurate risk assessment, further specific estimations of the changes in environmental conditions due to the construction of the reservoir will be required; and more over, the effects of the pollutants to the ecosystem will also need to be evaluated.     

Survey‐Based Approach for Hydrological Vulnerability Indicators Due to Climate Change: Case Study of Small‐Scale Rivers1

Jung, Yong and Minha Choi, 2012. Survey‐Based Approach for Hydrological Vulnerability Indicators Due to Climate Change: Case Study of Small‐Scale Rivers. Journal of the American Water Resources Association (JAWRA) 48(2): 256‐265. DOI: 10.1111/j.1752‐1688.2011.00608.x Abstract: The vulnerability indicators can be used to develop water resource policy in the context of climate change. The Delphi method, an interactive prediction technique, is an efficient way to apply weighting functionality to vulnerability indicators consisting of three parts: Exposure, Sensitivity, and Adaptive Capacity on climate change. The Delphi method is an anonymous iterative survey of expert opinion, which is then shared with other participants. A total of three different rounds were carried out. The first round was a problem selection set, and the second and third were the standard Delphi survey. Fifty‐eight experts (66% academic and 34% practitioner) were invited. The rates of reply were 59, 50, and 38% for the first, second, and third Delphi processes, respectively. The degree of consensus of the Delphi survey was validated via variance changes and Kendall’s W test. Exposure and Adaptive Capacity presented increased levels of agreement among respondents in their given priorities. Particularly strong convergence (0.20 to 0.71 in Kendall’s W) of the experts’ opinions for Adaptive Capacity was observed. The results of this study indicate that finalized factors with ultimate weights through the Delphi method can be a strong support for governmental policy making with respect to climate change.