An indicative method for determination of the most hazardous changes in slopes of the subsidence basins in underground coal mining area in Ostrava (Czech Republic)

Considering growing population and decreasing mineral resource reserves, the issue of undermining has been and shall remain very topical. This study aims to identify the mutual connections between mined out panels of a deposit and the final manifestations on the ground surface related to deep black coal mining. On the grounds of the identified connections, the study describes a method to simplify a common evaluation of undermined areas according to building site categories. Within the study, a demarcation of the areas was conducted in two localities in Czech Republic influenced by the effects of undermining in the Upper-Silesian Basin. In the allotment of the CSM Mine, an area unsuitable for founding structures was defined from the centre of the worked out workings to the distance of 175 m from the panel's edge, for which the corresponding break angle is 78.3°. Similarly, in the allotment of the Paskov Mine, an area unsuitable for founding structures was determined to the distance of 500 m from the panel's edge, for which the corresponding break angle is 50.2°. This demarcation may be implemented prior to deposit mining being aware of several physical-mechanical parameters of rocks in the deposit's overburden. Having mined out a particular section of a deposit, it is recommended to verify the values of break angle using the method described herein. The study may be applied as a relatively fast and effective method to evaluate future land use for planning.     

Spatial and temporal variations in traffic-related particulate matter at New York City high schools

Relatively little is known about exposures to traffic-related particulate matter at schools located in dense urban areas. The purpose of this study was to examine the influences of diesel traffic proximity and intensity on ambient concentrations of fine particulate matter (PM_2.5) and black carbon (BC), an indicator of diesel exhaust particles, at New York City (NYC) high schools. Outdoor PM_2.5 and BC were monitored continuously for 4–6 weeks at each of 3 NYC schools and 1 suburban school located 40 km upwind of the city. Traffic count data were obtained using an automated traffic counter or video camera. BC concentrations were 2–3 fold higher at urban schools compared with the suburban school, and among the 3 urban schools, BC concentrations were higher at schools located adjacent to highways. PM_2.5 concentrations were significantly higher at urban schools than at the suburban school, but concentrations did not vary significantly among urban schools. Both hourly average counts of trucks and buses and meteorological factors such as wind direction, wind speed, and humidity were significantly associated with hourly average ambient BC and PM_2.5 concentrations in multivariate regression models. An increase of 443 trucks/buses per hour was associated with a 0.62 μg/m³ increase in hourly average BC at an NYC school located adjacent to a major interstate highway. Car traffic counts were not associated with BC. The results suggest that local diesel vehicle traffic may be important sources of airborne fine particles in dense urban areas and consequently may contribute to local variations in PM_2.5 concentrations. In urban areas with higher levels of diesel traffic, local, neighborhood-scale monitoring of pollutants such as BC, which compared to PM_2.5, is a more specific indicator of diesel exhaust particles, may more accurately represent population exposures.     

An island approach to industrial ecology: towards sustainability in the island context

Many fields of study have employed geophysical islands in experimental design with a great deal of success. An island is a closed and bounded system in many respects and presents a manageable unit of study. The island microcosm has been the basis for significant advances in areas such as evolutionary biology, ecosystem ecology and physical anthropology. The same properties that make islands so useful to scientists present island populations with pressing sustainability challenges of limited resource availability and natural carrying capacity. This paper discusses the characteristics of the island context to show the severity and immediacy of these challenges. Based on this discussion, it is apparent that new approaches are needed to address sustainable development on islands. Island systems and the study of industrial ecology, which examines industry embedded within the finite natural environment, have much to gain from one another in this respect. Several industrial ecology case studies, primarily drawn from research in Puerto Rico, are presented to illustrate the compatibility of islands as a study unit in this field. Industrial ecology presents new solutions to the challenges of sustainable island development, while well‐defined island systems offer a unique opportunity for the approach of industrial ecology.     

Characterization of dioxin exposure in firefighters, residents, and chemical workers in the Irkutsk Region of Russian Siberia

The goal of this study was to characterize body burdens of polychlorinated dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) in three groups of Siberians living in the Irkutsk Region of Russia. These groups included firefighters exposed to a mixture of toxic substances extinguishing a large fire at the Shelekhovo Cable Factory in 1992, chemical workers from the Khimprom chemical plant, and residents living in proximity to large chemical factories in Sayansk and Angarsk. Blood samples from all groups were obtained in the fall of 1998. Dioxin analyses of samples were performed in Germany, Canada, and in a Russian dioxin laboratory in Ufa, Bashkortostan Republic. The average levels of dioxin toxic equivalents (TEQs) are 23.6 parts per trillion (ppt) total TEQ (PCDD/F only) in the disabled firefighters, 25.0 in the non-disabled firefighters, 28.7 in residents, and 45.6 in the Khimprom workers blood. Two workers did have elevated total TEQs of 91.4 and 102.2 ppt. Dibenzofurans and coplanar PCBs substantially contribute to the total elevated TEQ seen here. The average TEQs suggest levels of dioxin exposure in this part of the former Soviet Union not dissimilar to levels measured in industrialized countries of Europe and Northern America.     

Forest Integrity at Anthropogenic Edges: Air Pollution Disrupts Bioindicators

The response of corticolous lichens, bryophytes, and vascular plants to anthropogenic edges in northern hardwood forest preserves is compared in east-coast and mid-west (NW Minnesota) sites, using micro-epiphytes on red oak (Quercus rubra) and sugar maple (Acer saccharum). The drastically attenuated lichen flora in the east, apparently due to regional air pollution, restricts the usefulness of these bioindicators, even 120 km from New York City. The forest edge is not necessarily equated with increased light. Established edges may have pronounced shoot growth that shades epiphytes. In the absence of air pollution, lichen and bryophyte species exhibit individual responses to light, humidity, and substrate chemistry. Thus summary variables such as total cover or species richness have limited value as bioindicators of forest integrity.