Patterns and inventories of radioactive contamination of island sites of the Yenisey River, Russia

The distribution of radioactive contamination at three island sites downstream from the Krasnoyarsk Mining and Chemical Combine (KMCC) was studied with the objectives of mapping contamination levels, interpreting radionuclide distributions through consideration of alluvial processes and determining radionuclide inventories. Contamination was measured using in situ gamma spectrometry and landforms characterised using topographic surveying methods. Maximum (137)Cs contamination densities (700 kBq m(-2)) were found on low- and middle-level floodplains and low-lying interconnecting areas of Beriozovy Island (16 km from the KMCC). On Mikhin Island (180 km from the KMCC) maximum total (60)Co, (152)Eu and (154)Eu activity concentrations (30-40 kBq m(-2)) occur in low-lying areas inundated during flooding. Maximum (137)Cs and total (60)Co, (152)Eu and (154)Eu contamination densities on Cheriomukhov Island (250 km from the KMCC) were 390 and 50 kBq m(-2), respectively. Estimated (137)Cs inventories were 145, 148 and 16GBq for Beriozovy, Mikhin and Cheriomukhov Islands, respectively.     

Inactivation of Ascaris suum in a biodrying compost system

Pathogen contamination of waterways is a serious concern in dairy farming areas where livestock waste is applied to agricultural fields. As an alternative, a biodrying composting system dries collected livestock waste, reduces the strong odors, and has been proposed as a means of reducing, and even eliminating pathogens present in the waste. Therefore, the survival of pathogens in a biodrying composting system was investigated. Dairy farm livestock waste was piled in a biodrying storage shed where forced aeration and natural decomposition processes heated a major portion of the waste pile to temperatures exceeding 55 degrees C. Ascaris suum eggs were used as the surrogate species and inoculated into special chambers and placed at three different elevations at different intervals along the length of the pile. Control chambers were stored in water at 4 degrees C in the laboratory. Both compost and control chambers were removed at Day 4, 8, 12, 16, and 20. The eggs were extracted from the chamber medium and analyzed for viability. No viable eggs were recovered from any of the chambers removed from the compost pile, while >or=90% viability was observed in the control chambers. High temperatures and continued drying were the major contributing factors to the inactivation of the helminth eggs. The complete inactivation of A. suum eggs by the biodrying process encourages the storage and treatment of manure to high temperatures and reduced moisture conditions before field spreading to reduce the risk of harmful pathogens contaminating waterways and potential drinking water supplies.     

Predicting the transfer of radiocaesium from organic soils to plants using soil characteristics

A model predicting plant uptake of radiocaesium based on soil characteristics is described. Three soil parameters required to determine radiocaesium bioavailability in soils are estimated in the model: the labile caesium distribution coefficient (kd1), K+ concentration in the soil solution [mK] and the soil solution-->plant radiocaesium concentration factor (CF, Bq kg-1 plant/Bq dm-3). These were determined as functions of soil clay content, exchangeable K+ status, pH, NH4+ concentration and organic matter content. The effect of time on radiocaesium fixation was described using a previously published double exponential equation, modified for the effect of soil organic matter as a non-fixing adsorbent. The model was parameterised using radiocaesium uptake data from two pot trials conducted separately using ryegrass (Lolium perenne) on mineral soils and bent grass (Agrostis capillaris) on organic soils. This resulted in a significant fit to the observed transfer factor (TF, Bq kg-1 plant/Bq kg-1 whole soil) (P < 0.001, n = 58) and soil solution K+ concentration (mK, mol dm-3) (P < 0.001, n = 58). Without further parameterisation the model was tested against independent radiocaesium uptake data for barley (n = 71) using a database of published and unpublished information covering contamination time periods of 1.2-10 years (transfer factors ranged from 0.001 to 0.1). The model accounted for 52% (n = 71, P < 0.001) of the observed variation in log transfer factor.     

A proficiency testing scheme for aromatic hydrocarbons in air by the manual thermal desorption-GC method: a comparison of laboratory performance with the uncertainty requirements of the European Union Ambient Air Directive

The Workplace Analysis Scheme for Proficiency (WASP) is a proficiency testing scheme for the analysis of occupational hygiene and environmental air samples and is operated in the UK by the Health and Safety Laboratory. Since 1997, WASP has offered samples of benzene, toluene and m-xylene, at environmental levels on Tenax, and has about 35 laboratories participating, mostly from industry, local government and consultancy organisations in the UK. The results reported cover the first 10 rounds of the environmental analytes (1997-1999) and demonstrate the important role of proficiency testing in assessing the quality of laboratory performance. Estimates are obtained for within-laboratory precision and the total variability at each analyte level. The estimates of within-laboratory precision suggest that laboratories have more difficulty analysing toluene and m-xylene than benzene. Linear relationships for the reproducibility relative standard deviation (RSDT) with loading level are evident for the analytes at occupational levels. At environmental levels, the relationship between loading level and reproducibility is much less well defined. The standard deviation for the proficiency testing assessment for all three analytes at the environmental level is 14%, as derived from the benzene data. Expanded uncertainty estimates (k = 1.96), for the analysis of samples since the scheme started, are obtained from the average total variance, and are 27% for benzene, 39% for toluene and 36% for m-xylene. Although the linear trend of performance against round number was not significant at the 95% level of confidence (p = 0.23 for benzene, p = 0.3 for toluene and p = 0.32 for m-xylene), there was a general improvement in RSDT from 26-34% to about 8-13% 10 rounds later. Currently, for a laboratory to meet one of the data quality objectives in the Ambient Air Directive (indicative measurement of benzene, expanded uncertainty +/- 30% or less), it would have to achieve a level of analytical performance to satisfy the category 1 (best performance) limit of better than +/- 8.8%. In the last proficiency testing round, discussed in this paper, only 58% of laboratories obtained performance scores that indicated that they were able to consistently achieve this level of performance.     

Determinants of a Quality Wild Turkey Hunting Season

According to the National Wild Turkey Federation, there has been a 450% increase in the number of licensed wild turkey hunters since 1973. Unfortunately, there is a paucity of research articles focusing specifically on turkey hunting. Most human dimensions of wildlife research have focused on either deer or waterfowl hunting. In this study, dimensions of hunting quality, days afield, and harvest were examined among a sample of 739 Virginia fall turkey hunters. Quality of a hunting season, rather than a specific hunt, was examined. Principal components analysis (PCA) revealed five domains of attributes of a high-quality turkey-hunting season: wildlife interaction, education, being away, social interaction, and hunting skills. The domains of hunting quality revealed by the PCA are similar to domains found previously for spring turkey hunters as well as other types of hunters. Also examined were hunter perceptions of overall hunting quality, the number of days spent hunting turkeys during the fall season, and harvest success. For comparative purposes and agency needs, hunters were segmented into three categories based on days spent hunting: low frequency (1 to 2 days), medium frequency (3 to 4 days), and high frequency (≥5 days). The influence of these variables to respondents’ perceptions of overall quality was examined using a series of regression models. Variables found to be significant predictors of quality were wildlife interaction and harvest success. Hunters who killed a turkey reported a significantly higher quality season than those who did not kill a turkey.     

Irradiance-induced changes in the photobiology of <Emphasis Type="Italic">Halophila johnsonii</Emphasis>

The endangered seagrass Halophila johnsonii Eiseman, exhibits high-light adapted photophysiology consistent with its distribution in intertidal and shallow subtidal (0–3 m) coastal-lagoon habitats along 200 km of southeastern Florida. To examine the short-term responses of this seagrass to three controlled-irradiance treatments (PAR + UVA + UVB [full spectrum], PAR + UVA, and PAR only), greenhouse-acclimated plants were transferred to outdoor mesocosms during July–August 2002. Chlorophyll fluorescence, UV fluorescence, and samples for pigment extraction were collected in the greenhouse, prior to moving the plants outside and on days 1, 2, 3, 4, 6, 10, and 21 of the 24-day experiment. Typical of sun-adapted plants, effective quantum yields measured by pulse-amplitude modulated (PAM) fluorometry were relatively low in all treatments, ranging from 0.46 ± 0.09 (PAR only) to 0.58 ± 0.08 (PAR + UVA + UVB). In the PAR only treatments, there were strong effects on days 1 and 4, presumably because the irradiance in the greenhouse not only lacked all λ<400 nm, but also had low irradiance maxima (∼700 μmol photons m⁻² s⁻¹, compared with ∼1,500 μmol photons m⁻² s⁻¹ outside at midday). There were few treatment differences between PAR only and PAR + UVA treatments indicating little effect of UVA radiation on this species. Differences in effective quantum yields and relative electron transport rates between the PAR only and PAR + UVA + UVB treatments on day 4 indicated rapid acclimation to UVB radiation. Tissues of H. johnsonii contained compounds that absorbed strongly in the UV, with a λ_max at ∼345 nm (depending on the extraction solvent). Absorption peak maxima and minima changed over the course of the experiment but there were no significant light-treatment differences in any pigment parameters. Percent UV shield values, measured using a newly developed UVA PAM fluorometer, were highest the day after plants were transferred from the greenhouse to the outdoor mesocosms and declined significantly to pretreatment levels in all treatments by day 21. Percent UV shield exhibited a significant positive relationship with UV-absorbing pigment (UVP) absorbance, however, the absence of treatment effects suggests that the wavelengths inducing pigment synthesis must lie between 400 and 700 nm (PAR). The results indicate that H. johnsonii rapidly acclimates to high UVB and PAR which may largely explain its distribution in intertidal and shallow subtidal areas.     

Comments and recommendations regarding the hypothesis testing controversy

Hypothesis tests are routinely misinterpreted in scientific research. Specifically, the failure to reject a null hypothesis is often interpreted as support for the null hypothesis while the rejection of a null hypothesis is often interpreted as evidence of an important finding. Many of the most frequently used hypothesis tests are “non‐informative” because the null hypothesis is known to be false prior to hypothesis testing. We discuss the limitations of non‐informative hypothesis tests and explain why confidence intervals should be used in their place. Several examples illustrate the use and interpretation of confidence intervals. Copyright © 2007 John Wiley & Sons, Ltd.     

Reconstruction of Long-Term Changes in Lake water Chemistry,Zooplankton and Benthos of a Small,Acidified High-Mountain Lake: Magic Modelling and Palaeolimnogical Analysis

Starolesnianske pleso is a small and shallow acid lake in the High Tatra Mountains, situated at 2000 m above sea level, on granitic bedrock, with sparse and thin soil cover. When detailed measurements began in the 1980s Starolesnianske pleso had pH below 5 and only one species of cladoceran zooplankton, the ubiquitous Chydorus sphaericusPalaeolimnological investigations show changes in cladoceran zooplankton and chironomid zoobenthic assemblages since about 1920 and a major change in 1970–1980. The dynamic acidification model MAGIC was used to reconstruct changes in water chemistry over the past 150 years. The results from MAGIC agree well with the sediment record; pH levels gradually decreased from 6.5 in the mid-1800s to about 5.6 in 1920 (first response in biota) to below 5.0 by 1970, and concentrations of inorganic aluminium rose dramatically beginning about 1960. In the 1990s the lake water chemistry showed clear signs of reversal in acidification brought about by a major decline in S deposition.     

Trapping efficiency of selected adsorbents for various airborne pesticides.

A study was conducted to compare the efficiency of five adsorbents used by government and private laboratories to collect airborne pesticides. Six pesticides, acephate, chlordane, chlorpyrifos, diazinon, heptachlor, and propoxur, were vaporized in a closed system and collected on each of the adsorbents, Chromosorb 102, ORBO 42, ORBO 44 (chlordane and heptachlor only), polyurethane foam (PUF) or Tenax GC, by drawing 250 L of air through the adsorbent. There were no differences in collection efficiency of the five pesticides on Chromosorb 102, ORBO's 42/44, and PUF. The efficiency with Tenax was somewhat less with several of the pesticides.