Trace element levels in foetus-mother pairs of short-beaked common dolphins (Delphinus delphis) stranded along the French coasts

Tissues of foetus-mother pairs of common dolphins (Delphinus delphis) stranded along the French coasts (Bay of Biscay and English Channel) were analysed for their Cd, Cu, Hg, Se and Zn contents. In the kidneys, foetal Cd levels were extremely low, and strong relationships between Cu and Zn suggested the involvement of metallothioneins since early foetal life. The results also indicated a limited maternal transfer of Hg during pregnancy since levels in the tissues of foetuses were below 1 microg g(-1) w.wt. However, hepatic Hg levels in foetuses increased with body length, and were also proportionate to maternal hepatic, renal and muscular Hg levels. Lastly, affinities between Hg and Se in tissues would participate in Hg neutralisation in both mothers--through tiemannite granules--and fetuses--through reduced glutathione--counteracting the toxic effects linked to the particularly high quantities of methyl-Hg to which marine mammals are naturally exposed.     

Changes of AhR-mediated activity of humic substances after irradiation

Humic substances (HS) and natural organic matter (NOM) are natural organic compounds ubiquitous in the environment. However, some studies indicate that both HS and NOM can act as xenobiotics, e.g. induce hormone-like effects in fish, amphibians and invertebrates. Molecules of these substances contain a number of aromatic rings and conjugated double bonds--the so called chromophores. Irradiation of dissolved HS and NOM can lead to a series of photochemical reactions which can act on these substances itself, or on other substances present in aquatic environment along with HS and NOM such as e.g. xenobiotics. In our previous study, we have found significant interactions of five humic acids (HA) with cytosolic aryl hydrocarbon receptor (AhR) in an in vitro bioassay based on H4IIE-luc cells. In the present study, we have studied the changes in AhR-mediated activities both of HS and NOM after irradiation that simulated natural solar light. Nine different HS and two NOM samples were irradiated in Pyrex tubes with a medium-pressure mercury lamp for a duration of 0 to 52 h (which corresponds to 0-52 d natural solar radiation). Original concentrations of the samples were 50 mg L(-1), and the greatest concentration of HS and NOM photoproducts subsequently tested in the bioassay was 17 mg L(-1), which is an environmentally relevant concentration. After irradiation the absorbances of all the samples were less than the original materials. The AhR-mediated activity of the HA-Fluka and HA Sodium Salt were partially decreased by irradiation. The activities of other HS and NOM, that were either AhR-active or -inactive were not changed by irradiation. The results of the study demonstrate that AhR-mediated activities of two active HA is caused by both photo-stable and photo-labile AhR activators, while the other three active HA contain only photo-stable AhR activators. Potential mechanisms of the observed irradiation-induced changes in AhR-mediated activities are discussed.     

Application of ICP-QMS for the determination of plutonium in environmental samples for safeguards purposes

Aiming to determine the plutonium amount as well as its isotopic composition, in particular, in swipe samples for safeguards purposes, an analytical method was developed with a plutonium separation step based on extraction chromatography using 2 cm TEVA columns and detection with quadrupole ICP-MS applying an ultra-sonic nebulizer coupled with membrane desolvation system. The method was successfully applied to New Brunswick plutonium certified reference materials as well as to Lawrence Livermore National Laboratory round robin samples, based on the round robin samples provided by the Institute for Reference Materials and Measurements (Belgium), as part of the Regular European Interlaboratory Measurement Evaluation Programme (REIMEP), campaign 16 (isotopic abundances of plutonium in plutonium nitrate samples), with a total plutonium amount between 1 and 0.25 ng per sample. After the introduction of an additional separation step, it was also possible to carry out precise and accurate total plutonium, (240)Pu/(239)Pu, (241)Pu/(239)Pu and (242)Pu/(239)Pu atom ratios determination in sediment sample showing its applicability to environmental samples in general, reaching a detection limit equivalent to 5 mBq(239)Pu kg(-1).     

Stable and radioiodine concentrations in cow milk: dependence on iodine intake

For testing the potential use of stable iodine as a countermeasure to reduce radioiodine transfer to milk, concentrations of stable iodine and radioiodine in the milk of dairy cows fed different amounts of stable iodine were measured. The results indicated that, compared to a normal average stable iodine intake of about 20 mg d(-1) for cows, low iodine dietary intake (<1.5 mg d(-1)) resulted in a reduced transfer of radioiodine to milk by 25%, varying stable iodine intakes in the range of 10-500 mg d(-1) did have no significant effect; at stable iodine intake rates above 1000 mg I d(-1), a reduction by a factor of approximately two was achieved. The high dietary iodine intakes--being about 100 times the normal iodine supply--required to reduce the radioiodine transfer significantly, will result in stable iodine concentrations in milk in excess of advised or legal limits for human consumption. Nevertheless, the provision of stable iodine via the milk pathway might be considered for emergency situations when stable iodine is used as a preventative measure for dose reduction to humans.     

Generic approaches to transfer

A review of methods which have been used to describe and predict transfer of radionuclides in biota was undertaken. The intent was to identify approaches that might prove useful in extending predictive estimates to other organisms and environments. Empirical approaches, such as found in the use of transfer factors, were examined. Kinetic methodologies were also presented. Allometric functions, with their ability to make broad generalizations, were also discussed. Data from several earlier radioecological assessments were tested for their potential utility in developing allometric relationships, with the result implying that such an approach might prove useful.     

The value of Seasonal Correction Factors in assessing the health risk from domestic radon: a case study in Northamptonshire, UK

Following an intensive survey of domestic radon levels in the United Kingdom (UK), the former National Radiological Protection Board (NRPB), now the Radiation Protection Division of the Health Protection Agency (HPA-RPD), established a measurement protocol and promulgated Seasonal Correction Factors applicable to the country as a whole. Radon levels in the domestic built environment are assumed to vary systematically and repeatably during the year, being generally higher in winter. The Seasonal Correction Factors therefore comprise a series of numerical multipliers, which convert a 1-month or 3-month radon concentration measurement, commencing in any month of the year, to an effective annual mean radon concentration. In a recent project undertaken to assess the utility of short-term exposures in quantifying domestic radon levels, a comparative assessment of a number of integrating detector types was undertaken, with radon levels in 34 houses on common geology monitored over a 12-month period using dose-integrating track-etch detectors exposed in pairs (one upstairs, one downstairs) at 1-month and 3-month resolution. Seasonal variability of radon concentrations departed significantly from that expected on the basis of the HPA-RPD Seasonal Correction Factor set, with year-end discontinuities at both 1-month and 3-month measurement resolutions. Following this study, monitoring with electrets was continued in four properties, with weekly radon concentration data now available for a total duration in excess of three and a half years. Analysis of this data has permitted the derivation of reliable local Seasonal Correction Factors. Overall, these are significantly lower than those recommended by HPA-RPD, but are comparable with other results from the UK and from abroad, particularly those that recognise geological diversity and are consequently prepared on a regional rather than a national basis. This finding calls into question the validity of using nationally aggregated Seasonal Correction Factors, especially for shorter exposures, and the universal applicability of these corrections is discussed in detail.     

Presence, biotransformation and effects of sulfophenylcarboxylic acids in the benthic fish Solea senegalensis

The presence of linear alkylbenzene sulfonates (LAS) and their degradation intermediates, sulfophenylcarboxylic acids (SPCs), with concentrations up to 100 ppb has been found in surface waters taken from the estuary of the river Guadalete (Cádiz, SW of Spain). Higher concentrations were found at the sampling site located adjacent to the discharge outlet of a wastewater treatment plant (WWTP). The concentrations decreased downstream to a few ppb as a result of dilution, sorption, and degradation processes, which were taking place along the estuary. Once the presence of both xenobiotics was confirmed in the environment, an in vivo assay was conducted to study their biotransformation and effects in the benthic fish Solea senegalensis. A flow-through system was employed, consisting of an exposure phase (120 h) with environmental levels of the surfactant (200, 500 and 800 microg/L of 2?C(10)LAS), followed by a depuration stage (72 h). The generation of SPCs has been quantified during these phases in both water and fish, with LAS biotransformation shown in all cases. The antioxidant enzymes catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR), the phase II enzyme glutathione S-transferase (GST), and the phase III acid and alkaline phosphatases (AcP, ALP) were also estimated and utilized as biomarkers.     

Distribution and dietary regulation of an associated facultative Rhizobiales-related bacterium in the omnivorous giant tropical ant,Paraponera clavata

We document a facultative Bartonella-like Rhizobiales bacterium in the giant tropical ant, Paraponera clavata. In a lowland tropical rainforest in Costa Rica, 59 colonies were assayed for the prevalence of the Bartonella-like bacterium (BLB), 14 of which were positive. We addressed three questions: First, how does the prevalence of BLB within colonies vary with environmental conditions? Second, how does diet affect the prevalence of BLB in P. clavata? Third, how does the distribution of BLB among colonies reflect ambient differences in food resources and foraging habits? A variety of environmental variables that may be predictive of the presence of BLB were measured, and diet manipulations were conducted to test whether the prevalence of BLB responded to supplemental carbohydrate or prey. The ambient frequency of BLB is much higher in young secondary forests, but is nearly absent from older secondary forests. The prevalence of BLB inside field colonies increased over the duration of a 2-week carbohydrate supplementation; however, water and prey supplementation did not alter the prevalence of BLB. The diets of the colonies located in young secondary forest, compared to other habitats, have a diet richer in carbohydrates and lower in prey. The abundance of carbohydrate, or the relative lack of N, in a colony’s diet influences the occurrence of the BLB microbe in P. clavata. As experimental diet manipulations can affect the facultative presence of an N-cycling microbe, a consistent diet shift in diet may facilitate the emergence of tighter symbioses.     

Quantification and Genetic Analysis of Salivirus/Klassevirus in Wastewater in Arizona,USA

Salivirus/klassevirus sequences were identified in 7 (15 %) wastewater samples collected in Arizona monthly for a year, with the highest concentration of 2.28 × 10⁵ and 2.46 × 10⁴ copies/L in influent and effluent, respectively. This is the first report of quantification and genetic analysis of salivirus/klassevirus in water samples in the United States.     

Impact of an Alcohol-Based Hand Sanitizer Intervention on the Spread of Viruses in Homes

The objectives of this study were to determine the movement of a virus throughout a household and the impact of an alcohol-based hand sanitizer (ABHS) on reducing the movement and exposure of the virus to household members. Bacterial virus MS-2 was used as the surrogate for human enteric and respiratory viruses. Seven households with families having at least two children in the age range of 2–18 living in the home were used in this study. The hands of one adult family member were contaminated with 1 × 10⁸. MS-2 bacteriophage in each home. After 8 h, the hands of each family member (10 fingers) and 20 frequently touched fomites were sampled to determine baseline contamination without intervention. Within 8 h, MS-2 was detected on all of the family member’s hands and most of the fomites. The intervention consisted of providing the families in all selected homes with bottles of an ABHS, which were placed in the kitchen, bathrooms, and nurseries. Smaller individual bottles were provided for each family member greater than 12 years old to place in purses, pockets, backpacks, etc. The families were instructed to use the ABHS one time or three times during the day. For one and three uses, a statistically significant reduction of virus on un-inoculated and inoculated hands of ~99 % occurred within 8 h. Similar reductions occurred on fomites throughout the households (97–99 %). These results demonstrate that the use of an ABHS can significantly reduce transfer of a virus to the hands, and to the commonly touched surfaces within the household.