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El medi ambient és un dels reptes més importants del segle XXI. La conservació dels recursos naturals i la qualitat de l'aigua, l'aire, els sòls i els ecosistemes naturals o construïts és una condició bàsica per garantir un desenvolupament equilibrat i sostenible per les generacions futures. Les activitats esportives poden ser factors contaminants però, quan es duen a terme de manera responsable, poden participar en la protecció del medi ambient i dels recursos. Aquesta lliçó presenta conceptes generals sobre els reptes mediambientals, les responsabilitats i les accions del Moviment Olímpic, i la manera de desenvolupar activitats esportives relacionades amb el medi ambient. El medio ambiente es uno de los retos más importantes del siglo XXI. La conservación de los recursos naturales y la calidad del agua, el aire, los suelos y los ecosistemas naturales o construidos es una condición básica para garantizar un desarrollo equilibrado y sostenible para las generaciones futuras. Las actividades deportivas pueden ser factores contaminantes pero, cuando se llevan a cabo de manera responsable, pueden participar en la protección del medio ambiente y de los recursos. Esta lección presenta conceptos generales sobre los retos medioambientales, las responsabilidades y las acciones del Movimiento Olímpico, y la manera de desarrollar actividades deportivas relacionadas con el medio ambiente. Environment is one of the most important challenges of 21st century. Conserving natural resources and the quality of water, air, soils and of natural or build ecosystems is the basic condition to ensure a balanced and sustainable development for future generations. Sport activities can be polluting factors but, when realised in a responsible manner, they can contribute to the protection of the environment and resources. This lesson presents general concepts concerning environmental challenges, the responsibilities and actions of the Olympic Movement and the ways in which to develop sport activities with respect to the environment.

Composting (aerobic treatment of organic wastes) and digestion (anaerobic treatment of organic wastes combined with biogas production) are important waste management strategies with increasing significance in the European Union and Switzerland. Most of the compost produced is applied to agricultural soils, which hereby recycles nutrients and influences soil properties beneficially. However, compost can contain pollutants that may be hazardous for the soil ecosystem. The problem related to heavy metals had been recognised and measures for reduction were taken. Regarding organic pollutants, the current knowledge is insufficient for quality control and risk assessment. This thesis provides a comprehensive overview on organic contaminates in compost, digestate, and presswater and describes factors that may influence them. In the beginning an extensive literature review was carried out to summarize the current data. Compound classes to be analysed in Swiss composts and digestates were prioritized and analytical methods established. Polychlorinated biphenyl concentrations (∑ of PCB 28, 52, 101, 118, 138, 153, 180) were significantly higher in urban (median: 30 μg/kgdry weight (dw), n=52) than in rural samples (median: 14 μg/kgdw, n=16), which points – together with low concentrations in general – to aerial deposition on feedstock material as major input pathway to compost. Median polycyclic aromatic hydrocarbon (PAH) concentration was 3010 μg/kgdw (∑ of 16 PAH defined by the US EPA except dibenzo[a,h]anthracene, n=69). PAH levels were influenced by the organic matter degradation process (higher levels in digestate than in compost), the season of input material collection (spring/summer>winter>autumn), the particle size (higher concentrations in unsieved or sieved >20mm than in sieved to ≤ 20mm products), and maturity (lower concentrations in more mature composts). One fourth of the samples exhibited PAH concentrations above the Swiss guide value for compost (Ordinance on the Reductions of Risks linked to Chemical Products). These elevated concentrations can lead to considerable input of PAH to soil by compost application. To assess the major contributors of PAH in compost, characteristic PAH ratios and some molecular markers were considered, which pointed mainly to combustion origin of these contaminants. Multifactor statistical analysis indicated traffic emission, straw combustion and some asphalt abrasion as potential additional sources. Concentrations of other organic pollutants determined (dibenzo-p-dioxins and -furans, dioxin-like PCB, brominated flame retardants (BFR), perfluorinated alkyl substances (PFAS), di(2-ethylhexyl)phthalate, nonylphenol and chlorinated paraffins) were mostly above levels found in background soil, except for nonylphenol, which was not detected. Out of 269 pesticides analysed, 30 fungicides, 14 herbicides, eight insecticides and one acaricide were detected. For the first time, the fate of organic pollutants during full-scale composting and digestion was assessed. Concentrations of low chlorinated PCB increased during composting (about 30 %), whereas a slight decrease was observed for the higher chlorinated congeners (about 10%). Enantiomeric ratios of atropisomeric PCB were close to racemic and did not change. Levels of low molecular weight PAH were reduced during composting (50 to 90% reduction), whereas heavier compounds remained stable. However, as indicated above, conventional composting does not reduce PAH concentrations sufficiently to comply with Swiss guide values (see above). Further research is needed to i) identify measures to reduce PAH concentrations in digestate and compost, ii) to monitor organic pollutants that are still increasing in other environmental matrices (e.g. BFR and PFAS) or identify new compounds which have not been detected in compost yet, iii) to evaluate potential risk of compost application to soil by assessing the bioavailable fractions of organic pollutants and iv) to examine possible new input materials and co-substrates for composting and digestion.

Problems related to Dioxins contamination in Southern Vietnam are until now still a hot newsreel and controversy subject in international conferences as well as in many articles. The adverse effects of Dioxins residue from chemicals used by U.S. Army during the Vietnam War (Ranch Hand Operation 1961 to 1971) have caused many consequences not only to Vietnamese ecosystem and people but also to the U.S army veterans that participated in the war at that period as reported in many scientific reports. In Vietnam, since 1980 many studies have been carried out in collaboration with overseas scientists and laboratories on Dioxin contamination levels as well as its influences on ecosystem and human health. However, regardless of many efforts, up to now the problem of Dioxin contamination and its consequences is not yet completely and appropriately solved. There is still relative high Dioxins residue in the areas named as "hot spot" in Southern Vietnam and its contamination is causing the adverse effects on local residents. Nowadays, studies on this subject are relatively difficult to perform due to many factors: over 30 years passed; land use disturbance; degradation and transfer of dioxin into biological food web; population emigration; etc.. In addition, a lack of related documents and military secrets also contributed to this. With the support of SDC in frame of a collaboration project between Vietnam and Switzerland, we have carried out the research named "Sources and Fate of PCDDs and PCDFs in rural and urban ecosystem and food chains of South-Vietnam". Our research has examined integratelly the PCDD/Fs sources with special regard on the PCDD/Fs source from the war, but also consider the others possible sources such industrial and municipal combustions, agricultural used chemicals, etc. The selected locations for our research have been set up based on collected document from Division 10-80 and Office 33 (two responsible organizations for Dioxins and related problems in Vietnam): CamLo District – QuangTri Province; DaNang City; MaDa Forest and BienHoa City (BienHoa Airforce Base and BienHung Lake) – DongNai Province; and industrial zone – Thu Duc – Hochiminh City. Seventeen 2,3,7,8-PCDD/Fs congeners have been chosen for our research due to their high toxicities. Soil, sediment, municipal waste incinerator (MWI) bottom ash, fish tissue, and human adipose are selected as the matrices to examine the PCDD/Fs residue. The result showed that even after more than 30 years, the PCDD/Fs concentration based on i-TEQ value (especially for 2,3,7,8-TCDD) is still higher than guideline values in some countries: very high i-TEQ value in cultivate soil of CamLo district and DaNang City. For the area named "hot spot" such BienHoa Airforce Base and BienHung Lake, the i-TEQ value and 2,3,7,8-TCDD concentration in soil and sediment are superior than values proposed by Agency for Toxic Substance and Disease Registry (ATSDR), Canadian Council of Ministers of the Environment (CCME) and U.S Environmental Protection Agency (U.S. EPA). The PCDD/Fs concentration in fish tissue of BienHung Lake (catfish and snake-head) is superior in comparison with European Council (EC) standard. The dioxin contamination risk for local resident health is very high due to the lack of information and inconsiderable attention of responsible organizations about this problem. As BienHoa was selected as a case-study for PCDD/Fs transfer in food chain, using statistic methods (cluster analysis and Principal Component Analysis - PCA), we have showed a high similarity of PCDD/Fs profiles pattern between BienHoa Airforce Base soils, BienHung Lake sediments and fish tissue. The similarity in PCDD/Fs relative i-TEQ profiles between MWIs bottom ash and soil of industrial zone ThuDuc proves that industrial and municipal combustions are responsible sources for PCDD/Fs in the soil of such these zones. However in comparison with the sites contaminated by Agent Orange (A.O)/Dioxin, the PCDD/Fs contamination level in the industrial soil is lower and mainly dominated by PCDFs than PCDDs. The result also showed comparables i-TEQ values in BienHoa residents with inhabitants of industrial countries, however Vietnam is only developing and agricultural country. Beside that, 2,3,7,8-TCDD has been detected in many tested cases. 2,3,7,8-TCDD is the most toxic compound and related to the A.O/Dioxins from the war, unfortunately we have not enough data to assess the relationship between A.O/Dioxin residue and these samples. To find out this relationship it is necessary an integrated large-scale investigation. Result of our research serves as a base for set-up a reference laboratory for PCDD/Fs and dioxin-liked compounds research in the South of Vietnam. At present time, a small laboratory for PCDD/Fs analysis has been installed in IER and serves as a member of VietNam Dioxin Research Network.

Adverse effects on the environment have become a matter of increasing concern considering the increase of industrialization and of the amount of commercialized chemicals. At present, approximately 100'000 substances are on the market, 3000 are sold at high volumes. In Europe, 200 to 300 new substances are authorized every year (in Switzerland, approximately 50). Contamination is induced by consumption of numerous products frequently applied by private or professional users. Persistence and ecotoxicity of certain organic compounds contained in these products might have impacts on the quality of our environment. Knowledge on potential sources of these substances is the first step in order to limit their release. The project developed within the present PhD thesis aims at determining the sources of certain compounds by applying material flux analysis on the basis of sewage sludge. Presently, a large number of anthropogenic organic compounds originating from private households, craft industry, industry and stormwater is disposed of into the collector system and ends up in sewage sludge. Carbendazim, diuron, Irgarol 1051®, octhilinone, permethrin, tributyltin (TBT) and triphenyltin (TPT) comprise numerous applications as biocides and pesticides whilst methylbenzylidene camphor (4-MBC), octyl methoxy cinnamate (OMC), octocrylene (OC) and octyl triazone (OT) are used as UV-screens (type UVB) in a large number of cosmetic products. Their toxic effects on non-target organisms and their potential for bioaccumulation give rise to environmental concern. These substances are used as ingredients in products of daily use and are disposed of into wastewater. Due to their physico-chemical properties they are more or less lipophilic and are likely to persist in sewage sludge. On the basis of the analysis of sewage sludge samples from well characterized sites (catchments and wastewater treatment plants, WWTPs) it is possible to determine the sources (private households, craft industry, industry and stormwater). The first step of this study was the development of analytical methods which allow for quantification of these compounds in sewage sludge. Due to their different physico-chemical properties, four different methods were required. These methods have recovery rates ranging between 75 and 106 % and limits of detection in the order of μg/kg dry matter. The analysis of sludge from 12 sites obtained within 2 sampling periods show that most of the substances are present in all samples. Mean concentrations were 6,8 μg/kg dm (dry matter) for carbendazim, 9,5 μg/ kg d.m. for diuron, 98,1 μg/kg d.m. for permethrin, 148 μg/kg d.m. for TBT, 1777 μg/kg d.m.for 4-MBC, 110 μg/kg d.m. for OMC, 4834 μg/kg d.m. for OC and 5517 μg/kg d.m. for OT. Octhilinone was not detected whilst Irgarol 1051® and TPT were found in 7 and 11 samples, respectively. The transfer of these compounds from wastewater into sludge is an important parameter for material flux analysis on the basis of sewage sludge. A study on the fate of carbendazime and permethrin during wastewater treatment has been carried out on two WWTPs. Whilst removal of permethrin was high (>94%) up to 70% of carbendazime present in sewage were found in treatment plant effluents. Adsorption is an important process for removal of permethrin. However, only 4 to 15 % of the load in wastewater was transferred to sewage sludge. Carbendazim is mainly associated to the aqueous phase and thus, a very small quantity ends up in sludge (approximately 1%). Therefore, the loads found in sewage sludge are more or less representative for consumption of the compounds in the catchments according to their physico-chemical properties. Additionally, it has been shown that the part of permethrine ending up in sludge depends on the treatment techniques of the WWTPs. Thus, for comparison of the pollutant loads in sewage sludge between different sites their fate in the WWTPs has to be known. The loads per inhabitant of the three well characterized types of sites have been calculated in order to determine the sources of the substances. Type A comprises sites with a separate sewer system and a catchment where mainly private households are present. Type B has a combined sewer system collecting sewage from private households, craft industry and stormwater whilst type C comprises a combined sewer system which includes effluents from private households and industry as well as stormwater. The results are as follows: Stromwater is considered as main source of carbendazim in wastewater whilst diuron originates mainly from stormwater and from industrial effluents. Private households contribute significantly to the loads of permethrine and TBT in sewage. For UV-screens the loads from private households are also important but stormwater and industrial effluents are likely to be potential sources as well. A difference in consumption between rural (type A) and more urban sites (type B and C) is possible which might hamper a proper estimate of the sources of UV-screens.

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 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.