Characterisation of the physico-mechanical parameters of MSW

Following the basics of soil mechanics, the physico-mechanical behaviour of municipal solid waste (MSW) can be defined through constitutive relationships which are expressed with respect to three physical parameters: the dry density, the porosity and the gravimetric liquid content. In order to take into account the complexity of MSW (grain size distribution and heterogeneity larger than for conventional soils), a special oedometer was designed to carry out laboratory experiments. This apparatus allowed a coupled measurement of physical parameters for MSW settlement under stress. The studied material was a typical sample of fresh MSW from a French landfill. The relevant physical parameters were measured using a gas pycnometer. Moreover, the compressibility of MSW was studied with respect to the initial gravimetric liquid content. Proposed methods to assess the set of three physical parameters allow a relevant understanding of the physico-mechanical behaviour of MSW under compression, specifically, the evolution of the limit liquid content. The present method can be extended to any type of MSW.     

Identification of Workers at Increased Risk of Infection During a COVID-19 Outbreak in a Meat Processing Plant,France, May 2020

Food and Environmental Virology - On 13 May 2020, a COVID-19 cluster was detected in a French processing plant. Infected workers were described. The associations between the SARS-CoV-2 infection...     

Wintering Waterbirds and Recreationists in Natural Areas: A Sociological Approach to the Awareness of Bird Disturbance

Disturbance to wintering birds by human recreational activities has become a major concern for managers of many natural areas. Few studies have examined how recreationists perceive their effects on birds, although this impacts their behavior on natural areas. We surveyed 312 users on two coastal ornithological sites in Brittany, France, to investigate their perception of the effects of human activities on wintering birds. The results show that the awareness of environmental issues and knowledge of bird disturbance depends on the socioeconomic characteristics of each user group, both between the two sites and within each site. Results also indicate that, whatever the site and the user group, the vast majority of the respondents (77.6 %) believed that their own presence had no adverse effects on the local bird population. Various arguments were put forward to justify the users’ own harmlessness. Objective information on recreationists’ awareness of environmental issues, and particularly on their own impact on birds, is important to guide managers in their choice of the most appropriate visitor educational programs. We recommend developing global but also specific educational information for each type of user to raise awareness of their own impact on birds.     

A single key-odorant accounts for the pheromonal effect of rabbit milk: Further test of the mammary pheromone’s activity against a wide sample of volatiles from milk

Summary. In the rabbit, lactating females emit a volatile compound in milk, the mammary pheromone (MP), that triggers rooting for the nipple and its grasping in pups. Previous studies have shown that the MP seems to act selectively, in terms both of intensity and quality. Here, we aimed to add new evidence to these properties of the MP. Newborn rabbits (n=825) were submitted to an oral activation test allowing to measure their searching/grasping responses towards different stimuli. In Experiment 1 we assessed whether pups respond to the MP in an intensity-dependent manner. In Experiment 2 we assessed the activity of 20 volatiles previously identified in rabbit milk, other than the MP, which were never systematically tested for intensitydependence. The assays showed that a) neonatal responses are released by the MP only for a limited range of concentrations; b) the 20 other odorants from milk are inactive at any concentration. Thus, the MP appears to be the single volatile from rabbit milk that releases searching/grasping behaviour in pups.     

Odour-guided social behaviour in newborn and young cats: an analytical survey

Summary. This article surveys early chemosensory mechanisms regulating behaviour in neonatal and juvenile domestic cats (Felis sylvestris catus). It aims to retrieve material from the available literature which may promote a better understanding of the semiochemical system that supports female-to-kitten exchanges. Studies dealing with the development of olfaction from birth through weaning are presented in three sections. The first aims at locating developmental periods suitable for applying analytical procedures combining behaviour and chemistry. The second section offers a survey of observational and experimental work related to the role of olfaction in the social and feeding behaviour of kittens before weaning. The final section traces the current knowledge on the odour sources and substrates that may be involved in early mother-kitten transactions.     

Characterisation and seasonal variations of particles in the atmosphere of rural, urban and industrial areas: Organic compounds

Atmospheric aerosol samples(PM_(2.5–0.3), i.e., atmospheric particles ranging from 0.3 to2.5 μm) were collected during two periods: spring–summer 2008 and autumn–winter 2008–2009, using high volume samplers equipped with cascade impactors. Two sites located in the Northern France were compared in this study: a highly industrialised city(Dunkirk) and a rural site(Rubrouck). Physicochemical analysis of particulate matter(PM) was undertaken to propose parameters that could be used to distinguish the various sources and to exhibit seasonal variations but also to provide knowledge of chemical element composition for the interpretation of future toxicological studies. The study showed that PM2.5–0.3concentration in the atmosphere of the rural area remains stable along the year and was significantly lower than in the urban or industrial ones, for which concentrations increase during winter.High concentrations of polycyclic aromatic hydrocarbons(PAHs), dioxins, furans and dioxin like polychlorinated biphenyls(DL-PCBs), generated by industrial activities, traffic and municipal wastes incineration were detected in the samples. Specific criteria like Carbon Preference Index(CPI) and Combustion PAHs/Total PAHs ratio(CPAHs/TPAHs) were used to identify the possible sources of atmospheric pollution. They revealed that paraffins are mainly emitted by biogenic sources in spring–summer whereas as in the case of PAHs, they have numerous anthropogenic emission sources in autumn-winter(mainly from traffic and domestic heating).     

Benefits of systems thinking for a human and organizational factors approach to safety management

This paper highlights the value of systems theory and its application to human and organizational factors (HOF). HOF specialists consider multiple systems characteristics in their analyses but are often unaware of the relevant theory applied in their analysis. We argue that a structured effort to take key systems characteristics into account in HOF practice would increase the depth and breadth of safety management analyses and help HOF specialists to act more effectively on industrial socio-technical systems. First, the paper identifies the following seven system theory characteristics: constitution, multi-axis representation, limit, emergence, variety, coherence, and causal interaction, which are then illustrated with examples from the HOF field. Finally, we discuss the two main benefits of integrating system thinking in a HOF approach to safety management: (1) an improved understanding of the inner workings of an industrial socio-technical system; and (2) a compendium or a reference to guide for decision-making and the implementation of actions within the industrial socio-technical systems.     

Groundwater dependent ecosystems. Part I: Hydroecological status and trends

Groundwater dependent ecosystems (GDEs) include valuable ecosystems such as springs, wetlands, rivers, lakes and lagoons. The protection of these systems and services they provide is highlighted by international agreements, i.e. Ramsar convention on wetlands, and regional legislation, i.e. the European Water Framework Directive. Groundwater provides water, nutrients and a relatively stable temperature. However, the role of groundwater in surface ecosystems is not fully understood. The ecosystem can depend on groundwater directly or indirectly, and the reliance can be continuous, seasonal or occasional. This has implications for the vulnerability of ecosystems, as some may be easily affected by external pressure. Conceptual models and quantitative assessments of how groundwater interacts with the environment are needed. GDEs are also threatened by different land use activities and climate change. Hence, we need to understand how GDEs are affected by changes in groundwater quantity and quality, as severe groundwater changes have been observed in many regions. This study examines key aspects of GDEs (hydrogeology, geochemistry and biodiversity) in order to improve conceptual understanding of the role of groundwater in such ecosystems. The status and baseline of different types of GDEs are discussed, with particular emphasis on past evidence of environmental change and potential thresholds and threats in GDEs in various parts of Europe with different land use, climate and geology.     

Groundwater dependent ecosystems. Part II. Ecosystem services and management in Europe under risk of climate change and land use intensification

Groundwater in sufficient amounts and of suitable quality is essential for potable water supplies, crop irrigation and healthy habitats for plant and animal biocenoses. The groundwater resource is currently under severe pressure from land use and pollution and there is evidence of dramatic changes in aquifer resources in Europe and elsewhere, despite numerous policy measures on sustainable use and protection of groundwater. Little is known about how such changes affect groundwater dependent ecosystems (GDEs), which include various aquatic and terrestrial ecosystems above ground and inside the aquifer. Future management must take this uncertainty into account. This paper focuses on multiple aspects of groundwater science, policy and sustainable management. Examples of current management methods and practices are presented for selected aquifers in Europe and an assessment is made of the effectiveness of existing policies such as the European Water Framework Directive and the Habitat Directive in practice and of how groundwaters and GDEs are managed in various conditions. The paper highlights a number of issues that should be considered in an integrated and holistic approach to future management of groundwater and its dependent ecosystems.