Arsenic contamination in wood mice (Apodemus sylvaticus) and bank voles (Clethrionomys glareolus) on abandoned mine sites in southwest Britain

Arsenic can be highly toxic to mammals but there is relatively little information on its transfer to and uptake by free-living small mammals. The aim of this study was to determine whether intake and accumulation of arsenic by wild rodents living in arsenic-contaminated habitats reflected environmental levels of contamination and varied between species, sexes and age classes. Arsenic concentrations were measured in soil, litter, wood mice (Apodemus sylvaticus) and bank voles (Clethrionomys glareolus) from six sites which varied in the extent to which they were contaminated. Arsenic residues on the most contaminated sites were three and two orders of magnitude above background in soil and litter, respectively. Arsenic concentrations in the stomach contents, liver, kidney and whole body of small mammals reflected inter-site differences in environmental contamination. Wood mice and bank voles on the same sites had similar concentrations of arsenic in their stomach contents and accumulated comparable residues in the liver, kidney and whole body. Female bank voles, but not wood mice, had significantly higher stomach content and liver arsenic concentrations than males. Arsenic concentration in the stomach contents and body tissues did not vary with age class. The bioaccumulation factor (ratio of arsenic concentration in whole body to that in the diet) in wood mice was not significantly different to that in bank voles and was 0.69 for the two species combined, indicating that arsenic was not bioconcentrated in these rodents. Overall, this study has demonstrated that adult and juvenile wood mice and bank voles are exposed to and accumulate similar amounts of arsenic on arsenic-contaminated mine sites and that the extent of accumulation depends upon the level of habitat contamination.     

Study of solubility of isoproturon by its complexation with beta-cyclodextrin

The inclusion complexes of beta-cyclodextrin-isoproturon were prepared using techniques such as kneading, co-evaporation, and co-precipitation. These complexes were characterised for physical properties and spectral studies such as UV, FTIR, and 1HNMR spectroscopy. To investigate the stoichiometry of the complexes Phase solubility method was adopted. Most of the complexes showed an increase in the dissolution rate of the herbicide. The best results were obtained when inclusion complexes were prepared by co-precipitation and co-evaporation method. Findings of this paper will allow the rational use of isoproturon with increase in its efficacy.     

Differences in root uptake of radiocaesium by 30 plant taxa

The concentration of Cs was measured in the shoots of 30 taxa of plants after exposing the roots for 6 h to 0.1 microg radiolabelled Cs g(-1) soil. There were maximum differences between Chenopodium quinoa and Koeleria macrantha of 20-fold in Cs concentration and 100-fold in total Cs accumulated. There was a weak relationship between Rb (K) and Cs concentration across the 30 taxa, but a strong relationship within the Gramineae and Chenopodiaceae. Taxa in the Chenopodiaceae discriminated approximately nine times less between Rb and Cs during uptake than did those in the Gramineae. The lowest Cs concentrations occurred in slow growing Gramineae and the highest in fast growing Chenopodiaceae. If radiocaesium uptake by the Chenopodiaceae during chronic exposures shows similar patterns to those reported here after acute exposure, then the food contamination implications and the potential for phytoremediation of radiocaesium contaminated soils using plants in this family may be worth investigating.     

RDX and TNT residues from live-fire and blow-in-place detonations

Snow was used as a collection medium to examine 1,3,5-hexahydro-1,3,5-trinitrotriazine (RDX) and 2,4,6-trinitrotoluene (TNT) residues post-detonation of 60-, 81-, and 120-mm mortar rounds, 105- and 155-mm howitzer rounds, M67 hand grenades, 40-mm rifle grenades, and blocks of C4. Residue-covered snow samples were collected, processed, and analyzed for explosives without cross-contamination from previous detonations and other potential matrix interferences. Detonation trials were performed following standard military live-fire and blow-in-place techniques. When possible, replicate munitions were detonated under similar conditions to provide a more reliable estimation of the mass of unconsumed high explosive residues. Overall the amount of energetic residues deposited from live-fire detonations were considerably less than the energetic residues deposited by blow-in-place detonations.     

Effects of DDT ground-spraying against tsetse flies on lizards in NW Zimbabwe

The impact of DDT ground-spraying against tsetse flies on lizards was investigated in NW Zimbabwe. Nineteen species were recorded, 17 in mopane woodland and 11 on gritstone outcrops: Mabuya striata wahlbergii dominated trees and Mabuya quinquetaeniata margaritifer rocks. Mean frequency of M. s. wahlbergii declined significantly from 76% of lizards at untreated sites (n = 8), through 72% after three annual treatments (n = 4), to 48% after 4-6 treatments (n = 6). Sighting rates and proportion of trees occupied were also significantly lower at treated than untreated sites. Numbers on trunks (99% > 15 cm diameter) above 3 m increased significantly with years of treatment relative to those in the spray target area below 3 m. Total DDT loads rose significantly with number of annual treatments and were up to 263 microg g(-1) lipid (7 microg g(-1) wet body weight) after 3-6 years. The percentage of unaltered DDT increased with load, which was proportionately higher in thin than in fat lizards. The geometric mean total DDT level in M. s. wahlbergii was significantly higher than in outcrop species, and from treated woodland was elevated 21 times above that in lizards from treated outcrops. Frequency and sighting rates of Lygodactylus chobiensis in woodland and immature Agama kirkii on outcrops were significantly higher in treated than in untreated areas.     

The interaction of SO2 and root-knot nematode on tomato

Intermittent exposure of tomato plants (cv. Pusa Ruby) to SO(2) at 286 microg m(-3) (3 h every heavy third day for 75 days) induced slight chlorosis of leaves. At 571 microg m(-3), considerable chlorosis with browning developed on the foliage. These symptoms were more pronounced and appeared earlier on SO(2)-exposed plants infected with Meloidogyne incognita race 1 (Mi), especially in post- and concomitant-inoculation exposures. Mi and/or SO(2) significantly reduced different parameters of plant growth. Synergistic (positive) interactions between SO(2) and Mi occurred in concomitant- and post-inoculation exposures at 286 and 571 microg m(-3), respectively. In other treatments, an antagonistic (negative) interaction was observed. However, in a few cases, additive effects of SO(2) and Mi were also recorded. Intensity of root-knot (galling) was enhanced at both concentrations of SO(2), while reproduction (egg mass production) of Mi was enhanced in concomitant-inoculation exposures at 286 microg m(-3) and inhibited at 571 micro m(-3). Exposure to SO(2) and/or Mi decreased the number and size of stomata but increased the number and length of trichomes on both the leaf surfaces. Stomatal aperture was significantly wider in the plants exposed to 571 microg SO(2) m(-3) alone and in pre-, post-, and concomitant-inoculation exposures at 286 or 571 microg m(-3). Stomatal aperture was directly related to foliar injury and reductions in growth, yield, and leaf pigments.     

Isolation of salmonella bacteriophages from swine effluent lagoons

Bacteriophages (phages) associated with Salmonella were collected from nine swine manure lagoons in Mississippi. Phages were isolated by an enrichment protocol or directly from effluent. For enrichment, chloroform-treated samples were filtered (0.22 mum) and selectively enriched by adding a cocktail of Salmonella strains in trypticase soy broth. After overnight incubation at 35 degrees C, chloroform was added and samples stored at 5 degrees C. Enriched samples were tested by double agar layer (DAL) plaque assay against individual Salmonella isolates. Phage titers of 2.9 x 10(8) to 2.1 x 10(9) plaque forming units (pfu) per mL were produced, but estimation of phage titers in lagoons was not possible. For direct isolation, effluent was clarified by centrifugation, filtered (0.22 microm), and used in DAL plaque assays to select single-plaque isolates for 15 Salmonella strains. Plaque counts varied among Salmonella strains and lagoons. The most sensitive strain for direct phage recovery was ATCC 13311. Phage titers estimated by direct isolation with ATCC 13311 ranged among lagoons from 12 to 148 pfu per mL. In limited host range tests, 66 isolates recovered by the enrichment protocol produced plaques only on Enteritidis and Typhimurium strains of Salmonella and none produced plaques on lagoon isolates of Citrobacter, Escherichia, Proteus, Providencia, or Serratia. Electron microscopy (EM) showed purified enrichment isolates had Podoviridae morphology (tailless 50-nm icosahedral heads with tail spikes). Electron microscopy of clarified concentrated effluent showed 5.5:1 tailless to tailed phages. The isolated phages have potential as typing reagents, specific indicators, and biocontrol agents of Salmonella.     

Influence of geomorphological variability in channel characteristics on sediment denitrification in agricultural streams

Within fluvial systems, the spatial variability of geomorphological characteristics of stream channels and associated streambed properties can affect many biogeochemical processes. In agricultural streams of the midwestern USA, it is not known how geomorphological variability affects sediment denitrification rates, a potentially important loss mechanism for N. Sediment denitrification was measured at channelized and meandering headwater reaches in east-central Illinois, a region dominated by intensive agriculture and high NO(3)-N stream export, between June 2003 and February 2005 using the chloramphenicol-amended acetylene inhibition procedure. Sediment denitrification rates were greatest in separation zones, ranging from 0.6 to 76.4 mg N m(-2) h(-1), compared with riffles, point bars, pools, and a run ranging from 0 to 36.5 mg N m(-2) h(-1). Differences in benthic organic matter (r = 0.70) and the percentage of fine-grained sediments (r = 0.93) in the streambeds controlled much of the spatial variations in sediment denitrification among the geomorphological features. Although two meandering study reaches removed 390 and 99% more NO(3)-N by sediment denitrification than adjacent channelized reaches, NO(3)-N loss rates from all reaches were between 0.1 and 15.7% d(-1), except in late summer. Regardless of geomorphological characteristics, streams in east-central Illinois were not able to process the high NO(3)-N loads, making sediment denitrification in this region a limited sink for N.     

Phytoremediation of an aged petroleum contaminated soil using endophyte infected and non-infected grasses

Phytoremediation is a promising technique for cleaning petroleum contaminated soils. In this study, the effects of two grass species (Festuca arundinacea Schreb. and Festuca pratensis Huds.), infected (E(+)) and non-infected (E(-)) by endophytic fungi (Neotyphodium coenophialum and Neotyphodium uncinatum, respectively) on the degradation of petroleum hydrocarbons in an aged petroleum contaminated soil was investigated. Plants were grown in the soil for 7 months and unplanted soil considered as control. At the end of the experiment, total and oil-degrading bacteria, dehydrogenase activity, water-soluble phenols, total petroleum hydrocarbons (TPH) and polycyclic aromatic hydrocarbons (PAHs) contents were measured in the soil. The results demonstrated that E(+) plants contained more root and shoot biomass than E(-) plants and created higher levels of water-soluble phenols and dehydrogenase activity in the soil, while there was no significant difference in bacterial counts of planted soils. Planting stimulated total and oil-degrading bacterial numbers, dehydrogenase activity and the soil content of water-soluble phenols. Regardless of endophyte infection, PAH and TPH removal in the rhizosphere of plants were 80-84 and 64-72% respectively, whereas the removals in controls were 56 and 31%, respectively. It was revealed that TPHs in retention time range of n-alkanes with C(10)-C(25) chain lengths and TPH were more degraded in the rhizosphere of E(+) plants compared to E(-) ones. Thus, grasses infected with endophytic fungi could be more efficient for removal of TPH from oil-contaminated soils.