Natural releases from contaminated groundwater, Example Reference Biosphere 2B

Safety assessment is a tool which, by means of an iterative procedure, allows the evaluation of the performance of a disposal system and its potential impact on human health and the environment. Radionuclides from a deep geological disposal facility may not reach the surface environment until many tens of thousands of years after closure of the facility. The BIOMASS Programme on BIOsphere Modelling and ASSessment developed Examples of "Reference Biospheres" to illustrate the use of the methodology and to demonstrate how biosphere models can be developed and justified as being fit for purpose. The practical examples are also intended to be useful in their own right. The Example Reference Biosphere 2B presented here involves the consideration of alternative types of geosphere-biosphere interfaces and calculation of doses to members of hypothetical exposure groups arising from a wide range of exposure pathways within agricultural and semi-natural environments, but without allowing for evolution of the corresponding biosphere system. The example presented can be used as a generic analysis in some situations although it was developed around a relatively specific conceptual model. It should be a useful practical example, but the above numerical results are not intended to be understood as prescribed biosphere 'conversion factors'.     

Chemosensory cues allow male lizards<Emphasis Type="Italic"> Psammodromus algirus</Emphasis> to override visual concealment of sexual identity by satellite males

Males of many species of lizards show conspicuous breeding colors but, in some species, young competitively inferior males conceal their sexual identity by a female-like dull coloration that allows them to evade aggression from dominant males and to adopt an alternative satellite-sneaking mating tactic. However, large males of the lizard Psammodromus algirus reacted aggressively to young intruder males despite their female-like coloration, suggesting that they might have the ability to recognize competitor males by chemosensory cues. We experimentally manipulated the head coloration (brown vs orange) and scents (male vs female) of small young males. For staged agonistic encounters, we compared the response of resident unmanipulated large males to the different manipulated small males. When we manipulated only the color of small males, the response of resident large males was independent of the paint manipulation; brown and orange males elicited a similar aggressive response. However, when we also manipulated the scent, small males painted orange or brown, but bearing the scent of males, received a significantly higher number of aggressive responses than small males painted orange or brown, but bearing the scent of females. The results showed that, at close range, the reaction of large males to manipulated individuals was dependent on the scent, whereas color seemed to be less important. Coloration may be, however, more important in long-distance communication as shown by the outcome of the first encounters. Also, orange coloration may increase the intensity of the aggressive response. Effective sex recognition by territorial large males is important in natural situations to avoid sneak matings by young male competitors. Thus, even if small males visually conceal their sexual identity, chemosensory cues allow large males to identify them at close range.     

Sustainability indicators for tourism destinations: bibliometric analysis and proposed research agenda

Environment, Development and Sustainability - This study aims to provide various maps of the evolution, current situation and future lines of sustainability indicators for tourism destinations...     

Inhibition of plasma butyrylcholinesterase activity in the lizard Gallotia galloti palmae by pesticides: a field study

A field study was performed to evaluate the effect of exposure to organophosphorus (OP) and carbamate (CB) pesticides on the lizard Gallotia galloti palmae. Butyrylcholinesterase (BChE) activity was measured in the plasma of 420 lizards collected from agricultural and reference areas on the Island of La Palma (Canary Islands, Spain) in two sampling periods. Exposure to cholinesterase-inhibiting pesticides was evaluated by a statistical criterion based on a threshold value (two standard deviations below the mean enzyme activity) calculated for the reference group, and a chemical criterion based on the in vitro reactivation of BChE activity using pyridine-2-aldoxime methochloride (2-PAM) or after water dilution of the sample. Mean (+/- SD) BChE activity for lizards from agricultural areas was significantly lower (Fuencaliente site = 2.00 +/- 0.98 micromol min(-1) ml(-1), Tazacorte site = 2.88 +/- 1.08) than that for lizards from the reference areas (Los Llanos site = 3.06 +/- 1.17 micromol min(-1) ml(-1), Tigalate site = 3.96 +/- 1.62). According to the statistical criterion, the number of lizards with BChE depressed was higher at Fuencaliente (22% of males and 25.4% of females) than that sampled at Tazacorte (7.8% of males and 6.2% of females). According to the chemical criterion, Fuencaliente also yielded a higher number of individuals (112 males and 47 females) with BChE activity inhibited by both OP and CB pesticides. CBs appeared to be the pesticides most responsible for BChE inhibition because most of the samples showed reactivation of BChE activity after water treatment (63.3% from Fuencaliente and 29% from Tazacorte). We concluded that the use of reactivation techniques on plasma BChE activity is a better and more accurate method for assessing field exposure to OP/CB pesticides in this lizard species than making direct comparisons of enzyme activity levels between sampling areas.     

Ecotoxicological effects of metal pollution in two mollusc species from the Spanish South Atlantic littoral

Metal accumulation and some of their biochemical effects have been studied in oysters (Crassostrea angulata) and mussels (Mytilus galloprovincialis) of the South Atlantic Spanish littoral. Especial attention has been paid to antioxidant defences and oxidative damage to biomolecules. Deep differences in the response of oysters and mussels to metal pollution were found. Oysters, with the higher metal loads of both species, showed increased antioxidant defences, and less extensive oxidative damage. In contrast, mussels, which accumulated much lower metal concentrations, showed clear increases in oxidized biomolecules, in agreement with their low increases in the antioxidant defence mechanisms. Our results suggest that mussels are more sensitive and less well adapted to metal pollution, probably explaining their absence in the most contaminated studied site, Mazagón. We conclude that oysters can be used as more sensitive bioindicator of pollution in the South Spanish littoral, and as a suitable model to study the adaptation to metal pollution.     

Agro-environmental sustainability assessment using multicriteria decision analysis and system analysis

Transparency and reproducibility remain challenges for sustainability assessment, particularly in developing world contexts where formal scientific information is often limited. We posit that even in such contexts, sustainability assessment can be productive and informative if the underlying assumptions about sustainability are made transparent. Thus, the process of assessment can be as instructive as the results, if not more so. In this article, we describe and discuss how we combined multicriteria decision analysis and system analysis as a unified approach to sustainability assessment. This approach is transparent, practical, flexible, and reproducible; it also facilitates the development of recommendations for enhancing sustainability. We illustrate the approach with examples from a recent environmental sustainability assessment of irrigated commercial maize production in Sinaloa, Mexico.     

Importance of the polarity on nanostructured silica materials to optimize the hydrolytic condensation with molecules related to CO2 adsorption

Environmental Science and Pollution Research - The present work reports the changes for the mesoporous materials SBA-15 and KIT-6 associated with the structural, textural, and chemical properties...