Dose Assessment for Process Water Tunnels at Hanford Site

The RESRAD‐BUILD and RESRAD computer codes were used for dose assessment of the 105‐C Process Water Tunnels at the Hanford Site. The evaluation assessed three different exposure scenarios: recreational use, tunnel maintenance worker, and residential use. The recreationist and maintenance worker scenarios were evaluated by using RESRAD‐BUILD, a computer model for analyzing the radiological doses resulting from remediation and occupancy of structures contaminated with radioactive material. The recreationist was assumed to use the tunnels as an overnight shelter for eight hours per day for one week. The maintenance worker was assumed to spend 20 hours per year working in the the tunnel. Six exposure pathways were considered for both scenarios in dose assessment. The gradual removal of surface contamination over time and ingrowth of decay products were considered in calculating the dose at different times. The maximum dose would occur immediately after the release and was estimated to be 1.9 mrem/yr for the recreationist and 0.9 mrem/yr for the maintenance worker. The residential scenario was evaluated by using the probabilistic RESRAD code. It was assumed that total activity from the tunnels would be brought into the near‐surface layer by future human activities. Eight exposure pathways were considered. The maximum yearly dose for this very unlikely scenario would occur immediately after the release and was less than 4 mrem/yr for the maximally exposed individual. The assessment demonstrates that both codes are suitable for nuclear facility decontamination and decommissioning sites, where buildings and structures with residual radioactivity must be evaluated to facilitate property transfer or release.     

Quantifying dry NH3 deposition to an ombrotrophic bog from an automated NH3 field release system

Providing an accurate estimate of the dry component of N deposition to low N background, semi-natural habitats, such as bogs and upland moors dominated by Calluna vulgaris is difficult, but essential to relate nitrogen deposition to effects in these communities. To quantify the effects of NH₃ inputs to moorland vegetation growing on a bog at a field scale, a field release NH₃ fumigation system was established at Whim Moss (Scottish Borders) in 2002. Gaseous NH₃ from a line source was released along of a 60 m transect, when meteorological conditions (wind speed >2.5 m s^?1 and wind direction in the sector 180–215°) were met, thereby providing a profile of decreasing NH₃ concentration with distance from the source. In a complementary study, using a NH₃ flux chamber system, the relationships between NH₃ concentrations and cuticular resistances were quantified for a range of NH₃ concentrations and micrometeorological conditions for moorland vegetation. Cuticular resistances increased with NH₃ concentration from 11 s m^?1 at 3.0 μg m^?3 to 30 s m^?1 at 30 μg m^?3. The NH₃ concentration data and the concentration-dependent canopy resistance are used to calculate NH₃ deposition taking into account leaf surface wetness. The implications of using an NH₃ concentration-dependent cuticular resistance and the importance for refining critical loads are discussed.     

End‐state land uses,sustainably protective systems,and risk management: A challenge for remediation and multigenerational stewardship

This article discusses creating a sustainably protective engineered and human management system in perpetuity for sites with long‐lived radiological and chemical hazards. This is essential at this time because the federal government is evaluating its property as assets and attempting to reduce its holdings, while seeking to assure that health and ecosystems are not put at risk. To assist those who have a stake in the remediation, management, and stewardship of these and analogous privately owned sites, this article discusses current end‐state planning by reviewing the federal government's accelerated efforts to reduce its footprint and how those efforts relate to sustainability. The article also provides a list of questions organized around six elements of risk management and primary, secondary, and tertiary disease and injury prevention. Throughout the article, the U.S. Department of Energy (DOE) is used as an example of an organization that seeks to reduce its footprint, manage its budget, and be a steward of the sites that it is responsible for. However, the approach and questions are appropriate for land controlled by the Department of Defense (DOD), the General Services Administration (GSA), and other public and private owners of sites with residual contamination. © 2005 Wiley Periodicals, Inc.     

Preliminary Studies on Converting Agricultural Waste into Biodegradable Plastics—Part IV: Polysaccharide Containing Natural Materials

Corn distillers’ dry grain, corncob powder, hardwood powder, and sugar beet pulp were separately anionized by oxidation with sodium hypochlorite in aqueous solution. Solid reaction products instantly precipitated upon admixing each of the above-oxidized materials with soy protein isolate. Infrared spectra and differential scanning calorimetry supported the hypothesis that soy protein isolate complexed with all of the above-oxidized polysaccharides. Reaction products with either oxidized corn distillers’ dry grain or oxidized sugar beet pulp provided hard, brittle pellets with tensile strengths as high as 9.5 MPa, suggesting that these materials could be viable as biodegradable plastics.     

EPA’s Clean Air Act Operating Permit Rules

Title V of the Clean Air Act requires tens of thousands of air pollution sources to obtain an operating permit incorporating all applicable requirements under the Act. EPA recently promulgated its controversial Title V regulations, which establish the minimum elements for state permit programs.

The new permit system is among the most important changes made by the 1990 Clean Air Act Amendments, and will significantly alter the way companies comply with air pollution requirements. Previously, the Act only required certain sources to obtain a new source review permit before constructing or modifying the facility (although many states established operating permit systems on their own). Now, all states must adopt operating permit programs consistent with the minimum federal requirements, and submit them to EPA by November 1993. Even though EPA has established minimum requirements, these programs are likely to vary widely from state to state.     

Bird Species Assemblages as Indicators of Biological Integrity in Great Basin Rangeland

The study evaluates the potential for bird species assemblages to serve as indicators of biological integrity of rangelands in the Great Basin in much the same way that fish and invertebrate assemblages have been used as indicators in aquatic environments. Our approach was to identify metrics of the bird community using relatively simple sampling methods that reflect the degree of rangeland degradation and are consistent over a variety of vegetation types and geographic areas. We conducted the study in three range types (i.e., potential natural plant community types) in each of two widely separated areas of the Great Basin: south-eastern Idaho (sagebrush steppe range types) and west-central Utah (salt-desert shrub range types). Sites were selected in each range type to represent three levels of grazing impact, and in Idaho included sites modified for crested wheatgrass production. Birds were sampled by point counts on 9 100-m radius plots at 250-m spacing on each of 20 sites in each area during the breeding season. In sagebrush-steppe, 964 individuals in 8 species of passerine birds were used in analyses. Five metrics were significantly related to impact class, both when analyzed within range type and when analyzed with all range types combined. Species richness, relative abundance of shrub obligate species, and relative abundance of Brewer's sparrow were generally lower for the higher impact classes, whereas the reverse was true for dominance by a single species and for relative abundance of horned larks. In contrast, total number of individuals did not differ significantly as a function of impact class. In salt-desert shrub, a total of 843 birds in 4 species were included in analyses, 98% of which were horned larks. None of the metrics identified above was significantly related to impact class. Two metrics for breeding birds in sagebrush steppe (species richness and dominance) showed little overlap between values for the extremes of impact class, and thus they have potential as indicators of biological integrity. However, the sensitivity of these metrics appears to be greatest at the high impact end of the spectrum, which suggests they may have limited utility in distinguishing between sites having light and moderate impact.     

(Z)-Dodec-3-en-1-ol, a common major component of the trail-following pheromone in the termites Kalotermitidae

(Z)-Dodec-3-en-1-ol has been identified as the major component of the trail-following pheromone of nine species of Kalotermitidae belonging to six different genera, suggesting that this compound represents a common signal in this family of termites. The homogeneous nature of trail-following pheromones of Kalotermitidae well agrees with the monophyly of this family. It also supports the postulated position of this family as a sister group of the Rhinotermitidae and Termitidae, which also secrete C12-alcohols as trail-following pheromones. The significance of a trail pheromone in termites of the ‘one-piece’ life type, which spend their whole life within the same piece of wood, is discussed.     

Submesoscale distribution of Antarctic krill and its avian and pinniped predators before and after a near gale

We conducted two ship-based surveys of the nearshore ecosystem north of Livingston Island, Antarctica during 2–10 February 2005. Between the two surveys, a low-pressure system (963 mbar) passed through the area providing the opportunity to measure ecosystem parameters before and after a near gale. A ship-based multiple-frequency acoustic-backscatter survey was used to assess the distribution and relative abundance of Antarctic krill (Euphausia superba). Net tows, hydrographic profiles, and meteorological data were collected to measure biological and physical processes that might affect the krill population. During the survey, the distribution and behavior of several krill predators [chinstrap penguins (Pygoscelis antarctica), cape petrels (Daption capense), and Antarctic fur seals (Arctocephalus gazella)] were measured from the vessel by visual observations. The survey encompassed an area of roughly 2,500 km², containing two submarine canyons with one to the west and one to the east of Cape Shirreff, which had different abundances of krill and predators. Several aspects of the nearshore ecosystem changed after the near gale including: hydrography of the upper 100 m of the water column, phytoplankton biomass, the abundance and distribution of krill, and the distribution of some krill predators. Differences in these parameters were also measured between the two canyons. These changes in the physical and biological environment during the survey period are quantified and show that the ecosystem exhibited significant changes over relatively short spatial (tens of kilometers) and time (tens of hours) scales.     

Love bites: male fang use during coercive mating in wolf spiders

Evolutionary conflicts of interest between the sexes are common, as mating tactics and strategies that increase fitness benefits for one sex may incur costs for the other. As a consequence, antagonistic coevolution between the sexes often results in a complex arms race between male persistence and female resistance. Coercive mating (e.g., forced copulation) likely benefits males by increasing the probability of mating; however, costs to females may be high, including injury or even death. Here, we report on a study of the use of fangs by males of the wolf spider Schizocosa ocreata (Hentz) during forcible mating with resistant females, which results in hemolymph loss and scar tissue formation in females. Microscopic inspection revealed that fang wounds (evidenced by scar tissue) were absent on unmated (virgin) females but were found on mated females and were significantly more frequent in coercively mated females. Experimental fang immobilization studies found no difference in copulation success between experimental (fangs immobilized) and control (sham manipulation) males. However, males that had use of their fangs had significantly longer copulation duration. These findings represent a previously unknown male mating tactic in spiders and an unrecognized potential cost of mating for female spiders.