The reuse of reclaimed water for irrigation around the Mediterranean Rim: a step towards a more virtuous cycle?

Regional Environmental Change - Climate change and a growing population around the Mediterranean Rim are increasing the need for water and, consequently, the pressure on resources in terms of both...     

Management of the belgian coast: Opinions and solutions

Since the beginning of the 20th century the Belgian coast has undergone important changes of which an overview is presented here. To determine the view of the Belgian public on the Belgian coast and in order to obtain their opinions and solutions to the problems along the Belgian coast, a questionnaire survey was conducted with a total of 100 respondents divided into five groups, all active in the coastal zone. The five groups included (1) politicians on various levels of authority, (2) coastal entrepreneurs and business people, (3) naturalists and scientists, (4) coastal residents and (5) tourists. Coastal zone problems, as perceived by the different groups, and their solutions are discussed. Former municipalities, in particular, were held responsible for the current coastal problems. Most respondents were skeptic about the application of recent juridical instruments (e.g. the Dune Decree), the structural plans and their power to protect the remaining natural areas. The root of the problems seems to lie in lack of coordination and communication between different authorities responsible for the coastal zone.     

Pre-hatching fluoxetine-induced neurochemical,neurodevelopmental, and immunological changes in newly hatched cuttlefish

Embryonic and early postembryonic development of the cuttlefish Sepia officinalis (a cephalopod mollusk) occurs in coastal waters, an environment subject to considerable pressure from xenobiotic pollutants such as pharmaceutical residues. Given the role of serotonin in brain development and its interaction with neurodevelopmental functions, this study focused on fluoxetine (FLX), a selective serotonin reuptake inhibitor (SSRI, antidepressant). The goal was to determine the effects of subchronic waterborne FLX exposure (1 and 10 μg L^?1) during the last 15 days of embryonic development on neurochemical, neurodevelopmental, behavioral, and immunological endpoints at hatching. Our results showed for the first time that organic contaminants, such as FLX, could pass through the eggshell during embryonic development, leading to a substantial accumulation of this molecule in hatchlings. We also found that FLX embryonic exposure (1 and 10 μg L^?1) (1) modulated dopaminergic but not serotonergic neurotransmission, (2) decreased cell proliferation in key brain structures for cognitive and visual processing, (3) did not induce a conspicuous change in camouflage quality, and (4) decreased lysozyme activity. In the long term, these alterations observed during a critical period of development may impair complex behaviors of the juvenile cuttlefish and thus lead to a decrease in their survival. Finally, we suggest a different mode of action by FLX between vertebrate and non-vertebrate species and raise questions regarding the vulnerability of early life stages of cuttlefish to the pharmaceutical contamination found in coastal waters.     

Documentation of the endotoxins present in the ambient air of cotton fiber textile mills in Québec

Cotton workers are recognized as being at risk of developing occupational lung diseases. Some researchers have identified endotoxins as being a potential etiologic agent for some of the respiratory problems. This study wants to document the concentration of endotoxins found in the ambient air of textile mills where cotton fibers are handled and to identify the processing steps where the highest endotoxins concentrations in the air were found and the one where the relative limit values (RLVs) are exceeded. The 4 mills studied process cotton fibers. All the air samples were analyzed using the chromogenic Limulus Amoebocytes lysate LAL method using a kinetic detection principle based on the IRSST's standard method. In this study, a large variability in the concentrations of endotoxins in the air was observed, depending on the mill, the processing step, and the time. Despite these variations, some processes can be identified as being major generators of endotoxins in the ambient air of the mills. The highest concentrations were measured in the weaving and drawing processes and reached 10,000 EU m(-3) of air. The opening, cleaning, carding, spinning and drawing processes are the other major endotoxins generating processes with concentrations from 24 to 8,700 EU m(-3) of air. The endotoxins concentrations exceeded the RLVs for 55% of the workstations in this project. This study demonstrated that endotoxins levels in the cotton industry are high and appropriate control measures are needed.     

When mobility makes sense: A qualitative and longitudinal study of the daily mobility of the elderly

A majority of North Americans hopes to grow old in the suburbs. This aspiration depends upon their ability to drive and their access to a car. Because it is essential for everyday travel, car-mobility in the suburbs is becoming a symbolic goal. The meanings of mobility for elderly will evolve over time, notably as a result of changes in autonomy. However, the mobility of older adults is mainly understood in terms of daily trips. Little research has considered the temporal dimension of aging as an evolving process. This study aimed at understanding with a qualitative and longitudinal perspective how older people stay (auto-)mobile in their house and their neighborhood against the need to adapt to reduced autonomy and mobility over time. A group of 22 suburbanites aged from 62 to 89 was interviewed in 1999 and in 2006. The results show that even if older people succeed in increasing their mobility, they are headed for inevitable immobility. Among the environmental adaptation strategies that were observed, the constructed behaviors, the dependencies demanding additional supports as well as the social life modulate different evolving experiences of the city: the shrinking city, the fragmented city, and the city by proxy. The built environment is at the heart of a complex process in which the adaptation of mobility contributes to the emergence of new residential experiences.     

Rate of pesticide volatilization from soil: an experimental approach with a wind tunnel system applied to trifluralin

Pesticide volatilization to the atmosphere may be a major pathway of dissipation closely linked with environmental, physico-chemical and technical factors. Understanding the volatilization process requires systems that make it possible to control some of these factors. Wind tunnels meet to these criteria. The volatilization flux is determined from a mass balance, using the difference in atmospheric pesticide concentration between the entrance and the exit of the tunnel and the airflow rate. An experiment was carried out in June 2000 to study the repeatability of this technique. Volatilization of trifluralin was measured in three wind tunnels for 8 days with a sampling period varying between 3 h and 2 days. Pesticide concentration was determined by trapping by XAD-2 resin in a two-stage cartridge, solvent extraction and analysis by gas chromatography. Cumulated losses through volatilization reached 30% of the measured application dose after 8 days, with a variability of less than 20% between the three tunnels. Approximately 20% remained in the topsoil (0–2 cm), with a variability of 14% between the three tunnels. The decrease in the volatilization flux over time is coherent with the expected theoretical evolution for a volatile pesticide such as trifluralin and with previous experimental works.     

Socio-environmental implications of process-based restoration strategies in large rivers: should we remove novel ecosystems along the Rhône (France)?

River restoration efforts require interdisciplinary approaches involving fluvial geomorphology, hydraulic engineering, ecology, sedimentology, chemistry, social geography, and sociology. We investigated the functioning of artificial structures called “Casiers Girardon” (groyne fields) in the Rhône River. We assessed potential benefits and risks linked to removing the Rhône groyne fields in a restoration context, with particular focus on the potential for increased bank erosion. Hydraulic, morphological, chemical, ecological, and social issues resulting from dismantlement were studied for terrestrialized and aquatic Casiers Girardon. Only 10% of Casiers Girardon have maintained their aquatic features, whereas most of the Casiers are terrestrialized. Our results help to confirm the effectiveness of restoration actions; however, they also indicate uncertainties and additional knowledge needs, especially in regard to potential incompatibilities between Casier restoration and conservation. Then, an interdisciplinary conceptual model was developed to identify interventions to be considered in Casiers Girardon, according to their terrestrialization rate and physiochemical characteristics (connectivity, amount of gravel vs. fine sediment, contamination level). This model synthetizes scientific results and expert judgment and provides management recommendations based on ecological and sociological expectations about the restoration of Casiers Girardon. The model highlights high heterogeneity in functioning and ecological potential between terrestrialized and aquatic Casiers. Dismantling of terrestrialized Casiers has strong potential to provide multiple benefits, whereas aquatic Casiers could be maintained as valuable backwaters. The managing guidelines for the Casiers Girardon of the Rhône River should be adapted according to local conditions, as well as expected benefits and needs, and conducted in co-ordination with all actors involved in and affected by the restoration.     

Adaptation of the Daphnia sp. acute toxicity test: miniaturization and prolongation for the testing of nanomaterials

Manufacturing of nanomaterials (NMs) is often complex and expensive, and their environmental risks are poorly understood or even unknown. An economization of testing NMs is therefore desirable, which can be achieved by miniaturizing test systems. However, the downsizing of test vessels and volumes can enlarge the surface/volume ratio (SVR) which in turn can affect the bioavailable concentration of adsorbing substances like NMs. The present study focused on the miniaturization of the acute toxicity test with Daphnia magna. The adaptations were verified with three reference substances, the non-adsorbing potassium dichromate (K₂Cr₂O₇) and as potentially highly-adsorbing substances silver nanoparticles (AgNPs) and silver nitrate (AgNO₃). The miniaturized test was conducted in 24-well microtiter plates (MT) and simultaneously compared to the OECD standard test (ST). Furthermore, the test duration was prolonged from 48 to 96 h since NMs tend to show effects only after extended exposure. The toxicity of K₂Cr₂O₇ and AgNPs continued to increase within the prolonged test span. The test comparisons with K₂Cr₂O₇ did not reveal any significant differences between ST and MT. AgNO₃ toxicity was significantly decreased in MT compared to ST due to the enlarged SVR. The toxicity of AgNPs in MT after 24 h was equal to ST. Contrary to our expectations an exposure longer than 24 h resulted in an increase of AgNP toxicity in MT, possibly due to enhanced dissolution of silver. Microtiter plates are appropriate alternative test vessels for the Daphnia sp. acute toxicity test; thus, its miniaturization is feasible. The enlarged SVR has to be taken into account since it can affect the toxicity of potentially adsorbing substances. Furthermore, the standard test duration of 48 h might underestimate the toxicity of many substances, especially of NMs.