Measurements of 60Co in spoons activated by neutrons during the JCO criticality accident at Tokai-mura in 1999

Neutron activated items from the vicinity of the place where the JCO criticality accident occurred have been used to determine the fluence of neutrons around the facility and in nearby residential areas. By using underground laboratories for measuring the activation products, it is possible to extend the study to also cover radionuclides with very low activities from long-lived radionuclides. The present study describes gamma-ray spectrometry measurements undertaken in a range of underground laboratories for the purpose of measuring (60)Co more than 2 years after the criticality event. The measurements show that neutron fluence determined from (60)Co activity is in agreement with previous measurements using the short-lived radionuclides (51)Cr and (59)Fe. Limits on contamination of the samples with (60)Co are evaluated and shown to not greatly affect the utility of neutron fluence determinations using (60)Co activation.     

Early Development of Systems Analysis in Natural Resources Management from Man and Nature to the Miami Conservancy District

Contemporary approaches to natural resources and environmental decision-making typically draw on a “systems” perspective to assess and improve management strategies. This paper describes the early genesis of the systems analysis approach. It concentrates on a period between the mid-19th to early 20th centuries. During the early part of this period, George Marsh's Man and Nature and related works laid out an approach to problem-solving that recognized the relationship among physically disperse elements in the environment, the need to balance benefits against costs, the potential for using quantitative modeling to understand management options, and the importance of integrating human and natural components into solutions. In the early 20th century, the Miami Conservancy District project brought this approach to fruition with its use of complex simulation and optimization modeling, detailed cost–benefit analysis, and its linking of economics, engineering, science, and law into a far-reaching solution to a complex water resources problem. The objective of this paper is to describe the early development and application of this conceptual approach to problem-solving. An examination of the origins of natural resources systems analysis can broaden one's perspective of the contemporary field to understand its roots as a philosophy for environmental problem-solving.     

Simulation of Halocarbon Production and Emissions and Effects on Ozone Depletion

/ This paper describes an integrated model that simulates future halocarbon production/emissions and potential ozone depletion. Applications and historical production levels for various halocarbons are discussed first. A framework is then presented for modeling future halocarbon impacts incorporating differences in underlying demands, applications, regulatory mandates, and environmental characteristics. The model is used to simulate the potential impacts of several prominent issues relating to halocarbon production, regulation, and environmental interactions, notably: changes in agricultural methyl bromide use, increases in effectiveness of bromine for ozone depletion, modifications to the elimination schedule for HCFCs, short-term expansion of CFC demand in low use compliance countries, and delays in Russian Federation compliance. Individually, each issue does not unequivocally represent a significant likely increase in long-term atmospheric halogen loading and stratospheric ozone depletion. In combination, however, these impacts could increase peak halogen concentrations and long-term integral halogen loading, resulting in higher levels of stratospheric ozone depletion and longer exposure to increased levels of UV radiation.KEY WORDS: Halocarbons; Ozone depletion; Montreal Protocol; Integrated assessment     

Predictors for people's response to a tornado warning: Arkansas, 1 March 1997

On 1 March 1997, powerful tornadoes touched down in Arkansas (USA) on a Saturday afternoon. Twenty-six fatalities and 400 non-fatal injuries were reported. We performed a population-based cross-sectional study to determine factors associated with appropriate responses to tornado warnings. Of 146 survey participants, 140 (96 per cent) knew the difference between 'tornado watch' and 'tornado warning' and were aware of when the warning was announced. Of those 140 participants, 64 (45.7 per cent) responded to the warning by seeking shelter, and 58 (90.6 per cent) of those 64 acted within five minutes of hearing the warning. Four factors were positively associated with those seeking shelter: having graduated from high school (OR = 4.2, 95 per cent CI = 1.1-15.5); having a basement in one's house (OR = 3.8, 95 per cent exact CI = 1.1-17.1); hearing a siren (OR = 4.4, 95 per cent CI = 1.3-18.9); and having prepared a household plan of response when tornadoes occur (OR = 2.6, 95 per cent CI = 1.1-6.3). On the basis of these findings, we recommend: first, that people who live in tornadoprone areas have a personal plan of action to help them respond immediately to warnings; second, public-health education officials in areas with frequent tornadic activity should do more to educate the public about what they can do to protect themselves from a tornado; and third, that emergency-management officials planning protection measures for vulnerable communities should consider that most people have limited time (our study documented five minutes) in which to respond to a tornado warning. Thus, shelters in tornado-prone areas should be quickly accessible by residents.     

Maximizing Benefits from Riparian Revegetation Efforts: Local- and Landscape-Level Determinants of Avian Response

With limited financial resources available for habitat restoration, information that ensures and/or accelerates success is needed to economize effort and maximize benefit. In the Central Valley of California USA, riparian habitat has been lost or degraded, contributing to the decline of riparian-associated birds and other wildlife. Active restoration of riparian plant communities in this region has been demonstrated to increase local population sizes and species diversity of landbirds. To evaluate factors related to variation in the rate at which bird abundance increased after restoration, we examined bird abundance as a function of local (restoration design elements) and landscape (proportion of riparian vegetation in the landscape and riparian patch density) metrics at 17 restoration projects within five project areas along the Sacramento River. We developed a priori model sets for seven species of birds and used an information theoretic approach to identify factors associated with the rate at which bird abundance increased after restoration. For six of seven species investigated, the model with the most support contained a variable for the amount of riparian forest in the surrounding landscape. Three of seven bird species were positively correlated with the number of tree species planted and three of seven were positively correlated with the planting densities of particular tree species. Our results indicate that restoration success can be enhanced by selecting sites near existing riparian habitat and planting multiple tree species. Hence, given limited resources, efforts to restore riparian habitat for birds should focus on landscape-scale site selection in areas with high proportions of existing riparian vegetation.     

Consumer Choice and Farmers’ Markets

The increasing popularity of local food consumption can be attributed to the heightened awareness of food safety concerns, carbon emissions produced from food transportation, and an understanding of how large corporations’ obtain their food supplies. Although there is increasing discussion on both the local and organic food movement independently, there is not a wide availability of literature examining the motivations and perceptions of consumers with regard to farmers’ markets. Issues such as perceptions about what type of food consumers are purchasing at markets, nor the main motivations for frequenting such establishments are discussed. Therefore the purpose of this study was to determine consumer motivations, benefits, and perceptions of farmers’ markets. Using the case study location of Toronto, Canada, this study surveyed 300 participants during the fall of 2011. Findings indicated that the main purpose for visiting famers’ markets is not solely to fulfill grocery needs. Quality of products offered and the ability to support the local community were the primary motivators to visit the markets.