Spatial distribution of uranium and thorium in the surface soil around proposed uranium mining site at Lambapur and its vertical profile in the Nagarjuna Sagar Dam

The understanding and evaluation of the possible interactions of various naturally occurring radionuclides in the world's third largest man-made dam, Nagarjuna Sagar located in Andhra Pradesh, India and built on river Krishna assumed significance with the finding of uranium deposits in locations near the dam. For the present work, surface soil samples from the mineralized area of Lambapur, Mallapuram, Peddagattu and sediment core samples from the Nagarjuna Sagar dam were analyzed for naturally occurring radionuclides namely uranium and thorium using gamma spectrometric technique. Also toxic elements lead and chromium were analysed by the Energy Dispersive X-ray Fluorescence Spectrometer (EDXRF) technique. Surface soil samples show a variation from 25 to 291 Bq/kg (2.02–23.5 mg/kg) for ²³⁸U and 32–311 Bq/kg (7.9–76.9 mg/kg) for ²³²Th. U/Th concentration ratio in surface soil samples ranged from 0.19 to 0.31 and was found comparable with the nation wise average of 0.26. The study of sediment core samples reflected higher U/Th concentration ratio of 0.30–0.33 in the bottom section of the core as compared to 0.22–0.25 in the upper section. The concentration ratio in the upper section of the core was similar to the ratio 0.23 found in the western Deccan Basalt region through which the river originates. A higher concentration of lead and chromium was observed in the upper section of the core compared to bottom section indicating the impact of river input on the geochemical character of dam sediment.     

Reproductive parameters and disturbances of embryonic development in the fieldfare (<Emphasis Type="Italic">Turdus pilaris</Emphasis> L.) in the zone of impact from the nuclear fuel industry

The impact of emissions from the Siberian Chemical Plant (Tomsk oblast) on reproduction and embryonic development of the fieldfare was studied. Bird abundance, clutch size, and egg volume in the impact and background (control) zones were similar, but partial brood mortality in the impact zone proved to be significantly higher, and the frequency of embryonic pathologies (including developmental abnormalities) was also several times higher than in the control.     

Remote effect of nuclear polyhedrosis virus on the gypsy moth (<Emphasis Type="Italic">Lymantria dispar</Emphasis> L.) in its natural environment

The remote effect of the nuclear polyhedrosis virus on the gypsy moth was studied for the first time under natural conditions. In the generation that developed from infected eggs, the weight of pupae was reduced, sex ratio was altered, and female fecundity and egg fertility were lower than in control individuals. The F₁ progeny of these moths were characterized by an increased rate of latent virus carriage and high mortality caused by the combined effect of polyhedrosis and insect parasites.     

A detailed field-based evaluation of naphthenic acid mobility in groundwater

An anaerobic plume of process-affected groundwater was characterized in a shallow sand aquifer adjacent to an oil sands tailings impoundment. Based on biological oxygen demand measurements, the reductive capacity of the plume is considered minimal. Major dissolved components associated with the plume include HCO₃, Na, Cl, SO₄, and naphthenic acids (NAs). Quantitative and qualitative NA analyses were performed on groundwater samples to investigate NA fate and transport in the subsurface. Despite subsurface residence times exceeding 20 years, significant attenuation of NAs by biodegradation was not observed based on screening techniques developed at the time of the investigation. Relative to conservative tracers (i.e., Cl), overall NA attenuation in the subsurface is limited, which is consistent with batch sorption and microcosm studies performed by other authors. Insignificant biological oxygen demand and low concentrations of dissolved As (< 10 µg L^− 1) in the plume suggest that the potential for secondary trace metal release, specifically As, via reductive dissolution reactions driven by ingress of process-affected water is minimal. It is also possible that readily leachable As is not present in significant quantities within the sediments of the study area. Thus, for similar plumes of process-affected groundwater in shallow sand aquifers which may occur as oil sands mining expands, a reasonable expectation is for NA persistence, but minimal trace metal mobilization.     

Degassing of H/He, CFCs and SF6 by denitrification: Measurements and two-phase transport simulations

The production of N₂ gas by denitrification may lead to the appearance of a gas phase below the water table prohibiting the conservative transport of tracer gases required for groundwater dating. We used a two-phase flow and transport model (STOMP) to study the reliability of ³H/³He, CFCs and SF₆ as groundwater age tracers under agricultural land where denitrification causes degassing. We were able to reproduce the amount of degassing (R² = 69%), as well as the ³H (R² = 79%) and ³He (R² = 76%) concentrations observed in a ³H/³He data set using simple 2D models. We found that the TDG correction of the ³H/³He age overestimated the control ³He/³He age by 2.1 years, due to the accumulation of ³He in the gas phase. The total uncertainty of degassed ³H/³He ages of 6 years (± 2 σ) is due to the correction of degassed ³He using the TDG method, but also due to the travel time in the unsaturated zone and the diffusion of bomb peak ³He. CFCs appear to be subject to significant degradation in anoxic groundwater and SF₆ is highly susceptible to degassing. We conclude that ³H/³He is the most reliable method to date degassed groundwater and that two-phase flow models such as STOMP are useful tools to assist in the interpretation of degassed groundwater age tracer data.     

Predicting bioremediation of hydrocarbons: Laboratory to field scale

There are strong drivers to increasingly adopt bioremediation as an effective technique for risk reduction of hydrocarbon impacted soils. Researchers often rely solely on chemical data to assess bioremediation efficiently, without making use of the numerous biological techniques for assessing microbial performance. Where used, laboratory experiments must be effectively extrapolated to the field scale. The aim of this research was to test laboratory derived data and move to the field scale. In this research, the remediation of over thirty hydrocarbon sites was studied in the laboratory using a range of analytical techniques. At elevated concentrations, the rate of degradation was best described by respiration and the total hydrocarbon concentration in soil. The number of bacterial degraders and heterotrophs as well as quantification of the bioavailable fraction allowed an estimation of how bioremediation would progress. The response of microbial biosensors proved a useful predictor of bioremediation in the absence of other microbial data. Field-scale trials on average took three times as long to reach the same endpoint as the laboratory trial. It is essential that practitioners justify the nature and frequency of sampling when managing remediation projects and estimations can be made using laboratory derived data. The value of bioremediation will be realised when those that practice the technology can offer transparent lines of evidence to explain their decisions.     

The radiative efficiency of HCF2OCF2OCF2CF2OCF2H (H-Galden 1040x) revisited

The infrared spectrum of HCF₂OCF₂OCF₂CF₂OCF₂H (CAS# 188690-77-9) has been re-measured. The integrated absorption intensity over the range 1000–1500 cm^?1 measured in the present work is (6.65 ± 0.33) × 10^?17 cm² molecule^?1 cm^?1 in 700 Torr of air at 296 K. The radiative efficiency of HCF₂OCF₂OCF₂CF₂OCF₂H is calculated to be 1.02 W m^?2 ppb^?1. The value reported in the 2007 Intergovernmental Panel on Climate Change (IPCC) report is approximately 35% larger reflecting what we believe to be an erroneously high value for the absorption strength of HCF₂OCF₂OCF₂CF₂OCF₂H adopted by the IPCC.     

How organizational motives and communications affect public trust in organizations: The case of carbon dioxide capture and storage

Preventing climate change is among the greatest environmental challenges facing the world today. Recently developed carbon dioxide capture and storage (CCS) technology is an important strategy to mitigate climate change. Public trust in organizations involved in CCS technology is important for successful implementation of this technology. This work adresses how inferred organizational motives and organizational communications affect public trust in these organizations. Study 1 (N = 264) showed that Dutch citizens generally have less trust in the industrial organizations than in the environmental NGOs involved in CCS. As predicted, inferred organizational motives (organization-serving motives versus public-serving motives) accounted for this difference. In Study 2 (N = 78) and Study 3 (N = 51) we used experimental designs. Both experiments showed that organizations that communicated arguments incongruent with inferred organizational motives instigated less trust than organizations that communicated arguments congruent with inferred organizational motives. Study 3 additionally showed that communicating an incongruent and a congruent argument together diminished the negative effects of the incongruent argument. In both Study 2 and Study 3 the effect of congruency on trust was mediated by perceived honesty of the organizations.