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Justification In Sub-Saharan Africa, excreta and wastewater disposal is characterised primarily by on-site sanitation systems. This sanitation option is more likely to increase as governments, municipalities, communities, private operators and donor agencies strive to reach the Millennium Development Goals aimed at reducing by half the proportion of people without access to basic sanitation facilities. Due to increased urban population growth in Sub-Saharan Africa, the faecal sludge volumes will increase to alarming quantities in the coming decades. An evaluation of faecal sludge management practices reveals that the main shortcomings relate to the widespread lack of involvement and foresight by the municipalities, the paucity of effective legal provisions and organization, and the absence of stakeholder coordination. Stakeholder involvement for planning and implementing faecal sludge management is virtually inexistent or excluded from urban sanitation planning processes. In the majority of situations, faecal sludge management is financially not viable. This is a major cause of the indiscriminate dumping of faecal sludge in urban areas or its untreated use in urban agriculture. These practices not only pose permanent and serious health risks but also contaminate both scarce ground and surface water. Objective and general approach On the basis of these facts, which present a real challenge to sector specialists, the overall objective of our research is to develop an innovative strategic planning approach for sustainable faecal sludge management in urban areas which allows minimising public health and environmental risks. Focus is placed on developing a reproducible methodology for stakeholder involvement, on enhancing population awareness for improved faecal sludge disposal and attributing a leading role to the dynamic private faecal sludge emptying and transport operators. These aspects form the three pillars of our search for a comprehensive methodological approach. The municipality of Ouahigouya in Burkina Faso with a population of about 65'000 inhabitants was used as pilot site to launch, implement and scientifically validate the approach. Analysis and stakeholder involvement The stakeholder-based planning approach developed in Ouahigouya relies on a combination of stakeholder identification and analysis, and participatory planning techniques (focus groups, workshops, informal meetings, all-stakeholder workshops). A quantitative survey among households allowed collecting stakeholders' proposals and evaluating suggestions for improvement of faecal sludge management and neighbourhood hygiene proposed by the population. The main steps in the stakeholder involvement approach include: Jointly clarifying the objectives of the planning process together with the stakeholders; Identifying stakeholders and their interests; Classifying stakeholders according to their importance and influence based on defined criteria and confirmed by the stakeholders themselves; Identifying the interactions between the stakeholders; Verifying the results of the stakeholder analysis by the stakeholders themselves; Choosing stakeholder involvement techniques; Implementing the chosen method of stakeholder involvement: development of faecal sludge management scenarios, acceptance of the scenarios by the stakeholders in focus groups, choice and acceptance of a basic scenario for development of the future strategy in an all-stakeholder workshop; Evaluating the chosen involvement process by the stakeholders. The experience gained with the planning methods developed and implemented in Ouahigouya reveals that the "Stakeholder analysis" method is efficient and provides answers to questions such as: Who are the important and influential stakeholders? Who should participate in the planning process and in which manner? This experience also revealed the need for capacity building of certain stakeholder categories (emptying operators, women's associations, etc.) to increase their degree of involvement in the planning process. Improvement in stakeholder involvement was achieved thanks to a combination of workshops, focus groups and other informal meetings allowing less influential stakeholders (associations of local women, horticulturists, emptiers) to share information and to freely express their opinions and concern and to defend their interests. Thus, providing an excellent example of local democracy appreciated by all stakeholders of Ouahigouya. The approach developed provides tools for policy-makers and planners to ensure an effective stakeholder involvement in the process of developing a common vision and implementation of improved urban sanitation measures. The conditions for replicating the approach developed and tested in Ouahigouya are due to participatory democracy, great commitment of the local authorities and the high motivation of the stakeholders involved. Levers for the willingness-to-improve faecal sludge management and neighbourhood hygiene The evaluation method of the willingness to improve faecal sludge management by the population was based on a combination of the planned behavior model of Ajzen and the contingent valuation method, financial analysis of the pit emptying and faecal sludge enterprise, and on focus groups of stakeholders. By focusing on local practices, perceptions and individual behavior, this method revealed that financial viability – often reduced to willingness-to-pay – is not the only factor to consider when planning improvement of sanitation practices. Willingness-to-improve is highly dependant on psycho-sociological factors such as attitude towards and beliefs in an improved neighbourhood environment, social pressure on the households by the neighbourhood as well as the subjective costs and benefits expected from improved faecal sludge management. These factors therefore present levers allowing planners and decision-makers to encourage, increase and develop the demand for improved latrine emptying services, e.g. though social marketing. Promoting private entrepreneurs According to market analysis of emptying services and stakeholders involved, small private and mainly informal enterprises play a leading role in faecal sludge management in most cities of Sub-Saharan Africa. These operators, dynamic but fragile, require an appropriate institutional, jurisdictional and economic environment based on a balanced partnership between the municipality (public) and the private sector. Our study reveals that for a company truck to be profitable, about 1'000 trips per year (at 6'000 FCFA per trip) are required or the equivalent of a city of 56'000 inhabitants. In the case of Ouahigouya, profitability is increased if the emptying operators apply the latest management and professional tools and techniques, and manage to provide emptying services in neighbouring towns. Decision support tools The research led to developing decision support tools for professionals and policy-makers. These tools facilitate the development of a tariff-oriented policy to avoid uncontrolled faecal sludge discharge into the environment, to render investments by private operators profitable, and still make emptying services accessible to low-income households. This involves: Analysis of the cost structure of 3 pit emptying companies has revealed that fuel, maintenance/repair and personnel costs make up 45%, 20% and 30%, respectively, of an enterprise's operating expenses. An Excel programme was developed to allow municipalities and private operators to determine the operating costs of emptying services. This allowed to establish a sustainable money flux between the different stakeholders involved and to define the tariffs. To prevent faecal sludge discharges in the immediate residential environment or on unauthorised sites, it might under specific circumstances prove necessary and feasible to reimburse rather than charge entrepreneurs for delivering faecal sludge to the treatment sites, hence, create a strong incentive for good emptying and haulage practice. Evaluation methods of the sludge quantities to be disposed of have been developed to allow faecal sludge planning by the municipal authorities, assessment of the potential market and return on investment by the private operators. Advantages of the approach for the population of Ouahigouya Based on the results of our study, it was possible to formulate practical recommendations for the organisation of the urban sanitation sector for the municipality of Ouahigouya – now in possession of a sustainable faecal sludge management strategy. Our study has also contributed to promoting local consultation and raising the awareness of the role and contribution of each stakeholder group, in particular the previously neglected manual emptiers in their daily efforts to improve the living conditions of the urban inhabitants. The "Strategic Excreta and Wastewater Sanitation Plan", that was developed and supported by the "Office National de l'Eau et de l'Assainissement - National Water and Sanitation Agency", provides an excellent framework for the implementation of the elaborated faecal sludge management model (as part of the this strategic plan).

The major pathways of human pharmaceuticals into the environment are from their use by individuals either at home or under medical supervision in hospitals, and to a lesser extent by the disposal of unwanted or out of date drugs. The administered pharmaceuticals will be excreted as the parent compound, metabolite or conjugate and will be transported to sewage treatment works. In sewage treatment, the compound may be degraded or partially degraded, adsorbed to sludge if lipophilic, be deconjugated or pass through sewage treatment unchanged. Once in the environment the substance will be subject to further degradation processes. The first part of this research is dedicated to the occurrence and fate of five substances widely consumed in Switzerland: Clofibric acid (metabolite), Ibuprofen, Ketoprofen, Mefenamic acid and Diclofenac (Chapter 2). These acidic drugs were analyzed in three sewage treatment plants (STPs) over four to seven consecutive days. Ibuprofen, Ketoprofen, Mefenamic acid and Diclofenac are non-steroidal anti-inflammatory drugs (NSAIDs). Clofibric acid is an active metabolite of Clofibrate, Etofibrate, Etofyllinclofibrate which are drugs used as blood lipid regulators. The anti-inflammatory drug Ibuprofen and Mefenamic acid are the most sold substances of this study with 17 tons per year and per substance in Switzerland. Recoveries after filtration, extraction, derivatisation and clean-up generally exceeded 70%. Limits of detection (5-15 ng/l) and quantification (15-50 ng/l) were in a range which allows the detection and the quantification of these compounds in wastewaters. The results of samples analysis point out that the five substances were persistent in wastewater effluents after municipal wastewater treatment. At the most, half of Mefenamic acid was eliminated. Ibuprofen was well removed (80%) by one sewage treatment plant. The removal of Ibuprofen is depending on the residence time of wastewater in the STPs. A long raining period induce a important decrease of removal of Ibuprofen and Ketoprofen. Removal rates showed a great variability according to sewage treatment plants and types of treatments (e.g. biological, physico-chemical). The concentrations of Ibuprofen, Mefenamic acid and Diclofenac were relatively high in the effluents (150-2000 ng/l), showing a potential contamination of surface water. An environmental risk assessment is presented. Mefenamic acid seems to present the most important risk, followed by Ibuprofen, Clofibric acid, Diclofenac and Ketoprofen. But the risk ratio for surface water calculated with a dilution factor was above one only for Mefenamic acid. Since that toxicity of a single drug might be enhanced by the occurrence of other pharmaceuticals with similar activity, the overall risk of these drugs could be significant. To our knowledge, chronic ecotoxicity data are available only for Diclofenac and Clofibric acid. These kind of data are needed for the other chemicals to confirm our results. The second part of this thesis is dedicated to anticancer drugs (Chapter 3). Since the occurrence of anticancer drugs in the environment are few studied and that these substances are extremely toxic (teratogen, mutagen, etc.), it was interesting to evaluate the contamination of wastewaters by two of the most used anticancer drugs. Two methods were set up to analyse Tamoxifen and 5-Fluorouracil in wastewaters. A Liquid-liquid extraction (LLE) followed by a purification on OASIS® MCX cartridge and gas chromatography and mass spectrometry detection (GC-MS) were used for the analysis of Tamoxifen. 5-Fluorouracil was extracted with an ENV+ (Isolute) cartridge (solid-phase extraction), derivatised with pentafluorobenzyl bromide (PFBBr) and detected by GC-MS. Both methods showed good recoveries (>70%), reproducibility (RSD

In the past years, it has been observed that some compounds present in our environment can disturb the reproduction and development of animals like fishes, birds, or reptiles by interfering with their endocrine system. Indeed, these endocrine disrupting compounds (EDC) can mimic or antagonize the effects of hormones, alter the pattern of synthesis and metabolism of hormones or modify hormone receptor levels. These substances represent a risk for wildlife, and possibly for humans. Up to now, endocrine disruption was mainly evaluated for vertebrates and aquatic organisms and for oestrogeniclike substances. However, soil invertebrates, which play an important role in soil functioning, have rarely been considered. Moreover, as their endocrine system differs substantially from those of vertebrates (estrogens do not seem to regulate endocrine functions in invertebrates), other substances than can mimic invertebrate hormones should be taken into account. In this sense, insect growth regulators (IGR), which are third generation insecticides specially developed to interfere with insect endocrine system, are interesting compounds. These substances are supposed to have a high specificity for insect pest and a low toxicity for non-target organisms. In the first part of this study, the sublethal effects of six IGR (methoprene, fenoxycarb, precocene II, tebufenozide, hexaflumuron and teflubenzuron) were evaluated on the non-target soil arthropod Folsomia candida. The collembola F. candida represents an integral and beneficial part of the soil ecosystem. It is an euedaphic (subsurface) species which plays an important role in soil respiration and decomposition processes and is therefore vulnerable to the effects of soil contamination. This ecologically relevant organism is one of the most appropriate invertebrate test species for the assessment of environmental quality. It is recommended as test organism by the international standard ISO 11267. The 28-days reproduction tests conducted according to this protocol show that F. candida is affected by the chosen IGR. The most toxic compounds were the two chitin synthesis inhibitors, teflubenzuron and hexaflumuron, with an EC50 of 0.05 mg/kg (dw) for teflubenzuron and an EC50 of 0.6 mg/kg for hexaflumuron. These concentrations are probably environmentally relevant (toxicity/exposure ratios

The aim of this work is the modelling of the effects of a pollutant on an organism including time as a variable. The model developed will permit the evaluation of the toxicity globally, at short or long term, for low or high concentrations. This approach would permit the determination of values for very small effects or values for no-effect which could be utilised in the extrapolation of the laboratory results to the environment. To develop this approach, two organisms were chosen, a microcrustacea (Daphnia magna) and a green algae (Pseudokirchneriella subcapitata). The pollutant tested is a pesticide, dinoseb, which acts as a herbicide and as an insecticide. The measured effects are survival and reproduction for daphnids as well as growth, pH, chlorophyll a, photosynthesis and respiration for algae. To introduce time as a variable for the interpretation of the results, these parameters are measured during the life-cycle of daphnids and during the entire culture of algae. In the first part of this work, daphnids and algae cultures are studied to obtain a better knowledge of the biology of the organisms in laboratory conditions and to evaluate the natural variability of the measured parameters. For daphnids, this work permits us to establish a typical behaviour for survival and reproduction. This behaviour allows the evaluation of the quality of the cultures (and consequently of the test organisms) and the quality of a test, comparing the controls to the cultures. For algae, the study of the cultures permits us to establish the growth curve and the variability of the parameters measured during the test. In the second part, the effects of the pollutant on the different parameters are measured regularly to introduce time as a variable. The results show that dinoseb has an abrupt effect on daphnids and on algae, which could be attributed to the fact that the number of processes affected increases with the concentration. Indeed, dinoseb is a pesticide with a non specific mode of action. The range of concentrations producing effects on daphnids and algae are similar. For daphnids, the reproduction is slightly more sensitive than survival, and for algae, the growth is the most sensitive parameter. These parameters are therefore retained for the modelling. The variable time is directly taken into account in the survival time of daphnids. However, for the reproduction of daphnids and the growth of algae, the time must be introduced as a supplementary axis (longitudinal data). This results in a three dimensional graph with the effects measured as functions of time and concentration. In the third part, a model is adjusted to the survival data of daphnids. The model chosen is a simple logistic model with three interpretable parameters. It enables a global evaluation of dinoseb toxicity on survival. The model points out the effects on life-cycle time and on population for high and low concentrations. Its application permits us to define effects values (ECx, LCx), and especially a statistical no effect value which is more sensible then the NOEC (No Observed Effect Concentration). We propose to call this value SNEC (Statistical No Effect Concentration).The SNEC, as well as the other effect values, could be used for the evaluation of the impact of pollutants on the environment. This constitutes an interesting tool for ecotoxicology.

The aim of the present work is to study the sources and the dynamics of several organic priority pollutants in the soil's ecosystem. The principal organic pollutants studied are the polycyclic aromatic hydrocarbons (PAH) and the polychlorinated biphenyls (PCB). The PAHs contain carcinogenic substances and have a natural as well as an anthropogenic origin. They are produced, among others, by incomplete burning of fossil fuels or all other types of organic substances. PCBs are strong enzymatic inducing agents. They have a purely anthropogenic origin and are used mainly as dielectric fluids in electric transformers. The first chapter of this work gives some information about the production mechanisms, the sources and the toxicity of PAHs and PCBs. Their degradation pathways in the soil ecosystem are also discussed. The second chapter is based on the realization of total, 3 dimensional fluorescence figures of samples which contain PAHs. The program which is used was initially created for geodetic and photogrammetric purposes. The third chapter studies the inputs of organic micropollutants in agricultural soils. One of the most important PAH and PCB sources in soil ecosystems are atmospheric precipitations. The influence of sewage sludge spreading and the use of animal manure and mineral fertilizers in the contamination of soils by PAHs and PCBs are also investigated. The fourth chapter deals with the impact of PAHs on soil micro-organisms. Two respirometric tests are used to show the determinant effect which the soil structure plays in relation to the availability of PAHs on the activity of micro-organisms. The fifth chapter deals with the transfer of PAHs from the soil to earthworm tissues. By means of mass-spectrometry, modifications of the proportions of pollutants are shown in the earthworm tissues as opposed to that of the soil in which they live. The last chapter underlines the most important results of this work and draws the conclusions.