The Truth about Public Health Protection and Community Sewerage and Water Supply Sanitation in Developing Countries

Since the establishment, following World War II, of the World System, by which the affluent industrialized countries established various international assistance agencies (including the multilateral development banks, UN affiliates, and Bilaterals), these assistance agencies have invested very large sums in helping finance planning and construction of community sewerage and water supply facilities in the developing countries. However, much of this large investment has been ineffective and wasted, primarily because of the lack of understanding by the staff of the assistance agencies that the design criteria for the facilities must be modified to suit the socio-economic status of the developing country. The developing countries are relatively very poor in terms of available finances, hence cannot afford to emulate Western environmental standards and design practices, especially as related to operation and maintenance, hence much simpler approaches must be used. Experiences in several Asian countries are discussed, and a recommendation is made on how to go about resolving this problem.     

Landform Classification for Land Use Planning in Developed Areas: An Example in Segovia Province (Central Spain)

Landform-based physiographic maps, also called land systems inventories, have been widely and successfully used in undeveloped/rural areas in several locations, such as Australia, the western United States, Canada, and the British ex-colonies. This paper presents a case study of their application in a developed semi-urban/suburban area (Segovia, Spain) for land use planning purposes. The paper focuses in the information transfer process, showing how land use decision-makers, such as governments, planners, town managers, etc., can use the information developed from these maps to assist them. The paper also addresses several issues important to the development and use of this information, such as the goals of modern physiography, the types of landform-based mapping products, the problem of data management in developed areas, and the distinctions among data, interpretations, and decisions.     

The highly specialised gut of Fritillariidae (Appendicularia: Tunicata)

The morphology and some functions of the gut of Fritillaria pellucida and Fritillaria formica (Fritillaridae) were investigated by light and electron microscopy, and also by means of histochemical and immunohistochemical techniques. Fritillarids, very important for their abundance and ecological impact in marine ecosystems, have a very simplified gut: a straight oesophagus connects the pharynx to the digestive nucleus, composed of globular stomach and rectum, connected dorsally through a very short proximal intestine. The latter is characterised by a few (two to four) extremely specialised cells, completely filled with mitochondria associated tightly with membrane infoldings showing strong ATP-ase activity, and probably involved in the osmoregulation of internal body fluids. The gut is formed of an extremely low number of cells, which, although poorly diversified, are very large in the stomach and rectum. Food transfer along the gut depends on and is regulated by well-developed cardiac and pyloric valves, and signs of general digestive and absorptive activity are recognisable all along the brush border of the main tracts. The macroscopic organisation and cytological characters of the gut in fritillarids are completely different from those of the oikopleurids. In particular, fritillarids lack specialised cells for endocytosis and intracellular digestion, like those described in the genus Oikopleura. The general simplification and specialisation observed in Fritillaria gut may account for their elevated growth rate and abundant diffusion in all oceans.     

Rank-dependent hoarding effort in willow tits (<Emphasis Type="Italic">Parus montanus</Emphasis>): a test of theoretical predictions

Many birds and mammals store energy as hoarded food supplies. A supply of stored food is beneficial during periods when food is scarce, but building up and managing such a supply also entails costs. The optimal number of caches will be reached when the net benefit is at its maximum. If dominants can steal more stored food from subordinates than the other way around, the optimum will differ between these categories. A previous theoretical model of hoarding in groups with dominant and subordinate members produced three testable predictions: (1) hoarders should store more food as anticipated future conditions get worse; (2) subordinate flock members should store more food than dominants; and (3) dominants should increase hoarding relatively more than subordinates as conditions get worse. Here we present a field experiment on willow tits (Parus montanus) designed to test these predictions. We found support for all three. Hoarding increased as conditions got worse, subordinates stored at a higher rate than dominants, and dominants increased their hoarding effort relatively more than subordinates as conditions worsened. These results support the incorporation of information on dominance and food availability into models predicting food storage behaviour.Communciated by J. Dickinson     

Assessment of the leaching of metallic elements in the technology of solidification in aqueous solution

Results are presented of experiments performed to optimize the solidification/stabilization system for metallic elements in aqueous solution. This system involves mixing cement and a solution of metallic elements in a conventional mixer: the paste thus obtained is transferred drop by drop into a recipient filled with an aqueous solution of NaOH at 20% by weight, in which it solidifies immediately. The separate use of chloride solutions of Li+, Cr3+, Pb2+ and Zn2+ makes it possible to obtain granules displaying various levels of compressive strength. Three different inertization matrices were used in the experiments, the first consisting solely of Portland cement, the second of Portland cement and a superplasticizer additive, and the third of Portland cement partially replaced with silica-fume and superplasticizer. The results of the tests performed showed a very low level of leaching into the alkaline solidification solution for Cr3+, the quantity leached being under 2% as against higher levels for the other metallic elements. For all the considered elements, the best results were obtained by using silica-fume in the inertization matrix.     

Waste ecocompatibility in storage and reuse scenarios: global methodology and detailed presentation of the impact study on the recipient environments

In 1995, the ADEME launched a research program called "Waste Ecocompatibility" in order to define a reliable methodology for measuring the impact of waste in storage or reuse scenarios. The French concept of "Ecocompatibility" is defined as the situation where the pollutant flux from waste disposed of or used in specified conditions is compatible with the environmental acceptance of the receiving environments. The chief feature of this definition is to integrate the evaluation of the three following terms: pollutants emission from the waste, transport of the pollutants from the waste to the receptor cells and the environmental acceptance of the receiving environments. The "Waste Ecocompatibility" program consisted of a literature survey and an experimental part. The literature study aimed to determine factors and waste characteristics to be considered for a reliable ecocompatility assessment, to provide an overview of the available tools for measuring those factors and characteristics and to propose a first approach of the methodology. In the framework of the experimental program, this approach was then applied to three theoretical scenarios to validate the laboratory tools (comparative study of laboratory and field results) and to calibrate the global methodology. This paper deals with the results of the experimental program concerning the impact study on receiving environments: impact on plants and microorganisms living in soil, impacts on soil fauna and aquatic fauna. In other papers we intend to present the operational methodology for the assessment of waste ecocompatibility. It includes bio-assays at laboratory scale (microcosms), pilot scale (mesocosms) and in situ experiments (experimental prairie). To limit the use of in situ experiments other research works are necessary to validate bio-assays at laboratory or pilot scale.     

Leaching of inorganic contaminants from cement-based waste materials as a result of carbonation during intermittent wetting

Characterization of the leaching behavior of wastes is a crucial step in the environmental assessment for reuse or disposal scenarios. The release of inorganic contaminants from waste materials is typically evaluated by tank leaching of continuously water-saturated material. However, materials, in many field or management scenarios, experience cyclic wetting and drying under varied environmental conditions (i.e. variable relative humidity, atmospheric CO2 or CO2 from biologic activities). During periods of storage in an unsaturated environment, many processes may occur that can influence the release potential and release rate of inorganic constituents. The research presented here was carried out to examine how the phenomena of carbonation during drying influence the release of inorganic contaminants from Portland cement-based materials during cyclic wetting and storage. Batch equilibrium leaching tests were used to determine constituent solubility as a function of pH. Dynamic leaching tests on monolithic material were carried out to determine the rate of constituent release as a function of leaching time and intermittent storage conditions. This paper presents the results observed for three typical waste constituents, arsenic, cadmium and lead.     

Small-scale spatial and seasonal differences in the distribution of beach arthropods on the northwestern Tunisian coast. Are species evenly distributed along the shore?

Spatial distributions of sand beach arthropods were studied at Zouara (Nefza), a beach dune system along the northwestern coast of Tunisia. Two transects with pitfall traps, perpendicular to the shoreline and placed from sea towards land, captured spontaneously crawling arthropods. The pitfalls were used to obtain data on horizontal zonations for 2 days during different seasons (April, October). In April, in order to assess local, long-shore distributions of surface-active beach invertebrates, ten transects with pitfall traps were placed every 100 m, for 2 days. Core samples were also taken in correspondence with each of the ten transects to obtain the distribution of burrowing individuals. Sand samples were taken for successive laboratory analyses (salinity, grain size and organic contents). Local climatic conditions were also recorded. One isopod (Tylos europaeus, subdivided into three different size classes), two amphipods (Talitrus saltator, Talorchestia brito and indistinguishable juveniles) and four coleopteran species (Eurynebria complanata, Scarites laevigatus, Phytosus nigriventris, Phaleria acuminata) were considered. Mean zonations perpendicular to the shoreline showed that crustaceans were found closer to the sea-line limits than coleopterans and that between seasons some species changed their mean zonation more than others. Local, long-shore distributions of active and burrowing individuals showed that most species were unevenly distributed along the shore. These discontinuous distributions differed according to the species and age class and were mainly related to specific microclimatic conditions and to nutrition.     

Real-time, high-resolution quantitative measurement of multiple soil gas emissions: selected ion flow tube mass spectrometry

A new technique is presented for the rapid, high-resolution identification and quantification of multiple trace gases above soils, at concentrations down to 0.01 microL L(-1) (10 ppb). The technique, selected ion flow tube mass spectrometry (SIFT-MS), utilizes chemical ionization reagent ions that react with trace gases but not with the major air components (N2, O2, Ar, CO2). This allows the real-time measurement of multiple trace gases without the need for preconcentration, trapping, or chromatographic separation. The technique is demonstrated by monitoring the emission of ammonia and nitric oxide, and the search for volatile organics, above containerized soil samples treated with synthetic cattle urine. In this model system, NH3 emissions peaked after 24 h at 2000 nmol m(-2) s(-1) and integrated to approximately 7% of the urea N applied, while NO emissions peaked about 25 d after urine addition at approximately 140 nmol m(-2) s(-1) and integrated to approximately 10% of the applied urea N. The monitoring of organics along with NH3 and NO was demonstrated in soils treated with synthetic urine, pyridine, and dimethylamine. No emission of volatile nitrogen organics from the urine treatments was observed at levels >0.01% of the applied nitrogen. The SIFT method allows the simultaneous in situ measurement of multiple gas components with a high spatial resolution of < 10 cm and time resolution <20 s. These capabilities allow, for example, identification of emission hotspots, and measurement of localized and rapid variations above agricultural and contaminated soils, as well as integrated emissions over longer periods.