Éditeur(s) : Université de La Rochelle
Résumé : Shrimp aquaculture in New Caledonia is a developing industry, exclusively based on the species Litopenaeus stylirostris. However, it is subject to mortalities during grow out as observed all over the world. Since 1993, shrimp reared during the cold period are affected by a disease named "syndrome 93". As a consequence, the whole industry has become seasonal and produces essentially during the warm season. The climatic conditions during the periods of transition between the two main seasons could be responsible for an environmental stress and the origin reason for mortality outbreaks. Stocking density is the main risk factor. It increases the probability of the appearance and development of the epizooty in the pond. The "Summer Syndrome", a septicemic vibriosis caused by Vibrio nigripulchritudo, was identified for the first time in December 1997 in an intensive shrimp farm (DF). It has become enzootic ever since and is expressed after 50d of rearing. Since 2003, two others farms located near DF have developed the disease. As a consequence, the summer syndrome is considered to be a potential threat for all the industry. Between 1991 and 2005, the increase of feed input and nitrogen levels in feed has led to a significant increase in the growth rate over the years in the farms affected by the disease. In consequence, an early eutrophication of the water is observed, which is concomitant with the beginning of the mortality outbreaks. An early eutrophication and the virulence level of the pathogen are considered as the main risk factors of the disease. Factors may act synergistically to explain the summer syndrome. As part of a multidisciplinary approach (pathology – physiology – environment), two high-frequency surveys were carried out to analyse the pond ecosystem. Since the feed quantity increases with the biomass of shrimp, the eutrophication level of the pond ecosystem will also tend to increase with the duration of rearing. During the first part of the rearing, the abundance of each picoplankton type is exceptionally high and picophytoplankton dominated the autotrophic compartment. The nanophytoplankton dominated the second part of the rearing and was more unstable. The shift from pico to nanophytoplankton could be considered as an environmental stress and was observed in relation to the beginning of the mortalities, whatever the disease. Shift intensity could play a role by inducing directly or indirectly a stress for shrimp and/or a growth and/or virulence factors of the pathogen. Results from sediment studies show that mortality was best characterized by TAN concentration in pore water and even more when the TAN concentration was high. TAN and pH are potential stress factors for shrimp reared in ponds affected by these diseases.
L'aquaculture mondiale de crevettes est un secteur à très forte croissance. Toutefois, les problèmes liés aux maladies dans les élevages ne cessent d'augmenter depuis 1980. Au cours du développement de la filière de Nouvelle-Calédonie, deux épisodes saisonniers de mortalités associées à la présence de Vibrio pathogènes sont apparus et ont fortement perturbé les techniques et les schémas de production. Les premières mortalités hivernales, décrites sous le nom de « syndrome 93 » ont été observées en mai 1993. Elles ont affecté depuis tous les élevages de saison froide de toutes les fermes de production. Les conditions climatiques pendant les périodes de transitions entre les deux principales saisons caractérisant le climat de la Nouvelle-Calédonie, seraient responsables d'un stress environnemental à l'origine du déclenchement du syndrome 93. La densité initiale d'ensemencement, apparaît comme le principal facteur de risque, augmentant la probabilité d'apparition de la maladie et l'ampleur de ses effets. Le « syndrome d'été » a été identifié pour la première fois en 1997 dans une ferme pratiquant une production intensive. Il s'est déclaré depuis 2003 dans deux autres fermes géographiquement proches. Les mortalités apparaissent 58 jours en moyenne après l'ensemencement des post-larves dans les bassins. La recherche d'une croissance maximale des animaux a induit, avec les années, une intensification progressive du système caractérisée par une augmentation de la quantité d'aliment distribuée. L'examen des données historiques fait apparaître une eutrophisation du milieu de plus en plus précoce concomitante au déclenchement des mortalités. En l'état actuel de nos connaissances, cette évolution précoce de l'écosystème en présence de façon récurrente de la souche hautement pathogène du Vibrio incriminé et à une période où la fréquence des mues des crevettes est élevée, constitue le principal facteur de risque de la maladie. Avec l'apport croissant en aliment, la colonne d'eau évolue vers une autotrophie croissante alors que le sédiment devient de plus en plus hétérotrophe au fur et à mesure que l'élevage progresse. Au cours du processus d'eutrophisation, le compartiment autotrophe montre une succession de deux assemblages. Le picophytoplancton domine sur la première partie de l'élevage et laisse place à du nanophytoplancton en seconde partie. Cette phase de transition, concomitante à l'apparition des mortalités quel que soit le syndrome, caractérise un stress environnemental dont l'intensité pourrait favoriser ou non le déclenchement des mortalités. Les suivis de différents indicateurs dans les sédiments - pH, potentiel d'oxydoréduction et concentration en ammoniaque dans l'eau interstitielle – indiquent dans les bassins déclarant les épizooties des conditions qui ont été définies expérimentalement comme potentiellement plus stressantes pour les animaux.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/2007/these-2643.pdf
http://archimer.ifremer.fr/doc/00000/2643/

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
BACKGROUND: Sampling design is a key issue when establishing species inventories and characterizing habitats within highly heterogeneous landscapes. Sampling efforts in such environments may be constrained and many field studies only rely on subjective and/or qualitative approaches to design collection strategy. The region of Cacao, in French Guiana, provides an excellent study site to understand the presence and abundance of Anopheles mosquitoes, their species dynamics and the transmission risk of malaria across various environments. We propose an objective methodology to define a stratified sampling design. Following thorough environmental characterization, a factorial analysis of mixed groups allows the data to be reduced and non-collinear principal components to be identified while balancing the influences of the different environmental factors. Such components defined new variables which could then be used in a robust k-means clustering procedure. Then, we identified five clusters that corresponded to our sampling strata and selected sampling sites in each stratum. RESULTS: We validated our method by comparing the species overlap of entomological collections from selected sites and the environmental similarities of the same sites. The Morisita index was significantly correlated (Pearson linear correlation) with environmental similarity based on i) the balanced environmental variable groups considered jointly (p = 0.001) and ii) land cover/use (p-value<0.001). The Jaccard index was significantly correlated with land cover/use-based environmental similarity (p-value = 0.001). CONCLUSIONS: The results validate our sampling approach. Land cover/use maps (based on high spatial resolution satellite images) were shown to be particularly useful when studying the presence, density and diversity of Anopheles mosquitoes at local scales and in very heterogeneous landscapes.
BMC Ecology

pasteur-00914104
https://hal-riip.archives-ouvertes.fr/pasteur-00914104
https://hal-riip.archives-ouvertes.fr/pasteur-00914104/document
DOI : 10.1186/1472-6785-13-45
PUBMED : 24289184

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
PURPOSE: Dairy farming is a risk factor for the development of chronic obstructive pulmonary disease (COPD). We assessed the prevalence of farming-induced COPD (FI-COPD) using a new screening device, and we analyzed symptoms and occupational risk factors. METHODS: We performed on-site screening study of bronchial obstruction using an electronic mini-spirometer (EMS) on an entire population of dairy farmers (n = 147) from two villages in Brittany, France. Suspected bronchial obstruction (FEV1/FEV6 <0.8) was confirmed with standardized lung function tests (FEV1/FVC ≤0.7). We assessed past medical histories, respiratory symptoms, and occupational tasks of subjects with bronchial obstruction; asthmatics were defined as atopic and/or reversible; smoking-induced COPD patients were defined as non-reversible, non-atopic with smoking histories (≥5 PY); and FI-COPD patients were defined as non-reversible, non-atopic, and non-smokers. RESULTS: Using the EMS, 30.6% (n = 45) of dairy farmers were suspected of bronchial obstruction and underwent standardized spirometry. The FEV1/FEV6 ratio and FEV1/FVC ratio were in good agreement (r² = 0.66, P < 0.0001). The prevalence of confirmed bronchial obstruction was 9.5% (n = 14), which included 4 asthmatics, 3 smoking-induced COPD subjects, and 7 FI-COPD subjects. All the COPD patients were GOLD Stage II, and none were aware of their respiratory disease. Foddering duration was significantly higher in FI-COPD subjects compared with non-obstructive subjects, with 44 versus 17 min/day, respectively. CONCLUSIONS: The EMS was a convenient mean of screening for bronchial obstruction, especially in on-site settings, and allowed us to diagnose FI-COPD in a non-spontaneously complaining dairy farmer population. Foddering was considered a significant risk factor.
ISSN: 0340-0131

hal-00872929
https://hal.archives-ouvertes.fr/hal-00872929
DOI : 10.1007/s00420-011-0708-6
PUBMED : 21986906

Éditeur(s) : HAL CCSD
Résumé : Pregnancy is a sensitive and critical period for the development of the child and the health of adults-to-be. The biological and physiological adaptation of the body dealing physical and psychosocial stressors during this period may exert its effects in adulthood (and possibly over several generations). This delayed toxicity presupposes intrinsically the need to study the effects of exposure to environmental risk factors during fetal life using a holistic approach involving risk factors at both the micro (individual characteristics) and the macro level (physical and psycho-social context). Given the heterogeneity of the Breton territory in which this work was conducted, we explored whether the impact of social inequalities and the physical environment (air pollution) on birth outcomes (fetal growth and the risk of prematurity) could be modified according to an urban or rural place of residence. This work was based on data collected as part of the Breton mother-child cohort PELAGIE, which had included 3421 pregnant women between 2002- 2006. The anthropometric parameters and gestational age at birth were measured by medical personnel at delivery. We defined urban and rural areas according to the definition of “urban units” from the National Census Bureau (INSEE). The annual concentrations of air pollution (nitrogen dioxide (NO2)) were estimated using a land-use regression modeled at a 100 m scale and developed as part of an European project. Finally, neighbourhood deprivation was estimated using a composite index developed at census blocks level and whose use was legitimated over both urban and rural areas. Neighbourhood deprivation was associated with an increased risk of infants with fetal growth restriction, only for women living in rural areas. We also observed an increased risk of preterm birth associated with NO2 concentrations > 16.4 μg.m-3, only among women residing in urban areas. The associations between air pollution and fetal growth, although sex-specific, did not seem on the other hand, to vary significantly according to the urban-rural spectrum. This work confirms the need to explore the influence of both social and environmental inequalities on intrauterine development, and to assess the role of place-based factors, such as the urban-rural context, in shaping these inequalities.
La grossesse est une période sensible et déterminante pour le développement de l’enfant et l’état de santé à l’âge adulte. L'adaptation biologique et physiologique de l'organisme face à des « stresseurs » physiques et psychosociaux au cours de cette période peut ainsi exercer ses effets à l'âge adulte (et possiblement sur plusieurs générations). Cette toxicité différée suppose intrinsèquement la nécessité d’étudier les conséquences des expositions environnementales au cours de la vie foetale et ce suivant une approche holistique intégrant autant les facteurs de risque à des niveaux micro (caractéristiques individuelles) et macro (expositions physiques externes et contexte psycho-social). Etant donné l’hétérogénéité du territoire breton dans lequel s’inscrit ce travail de thèse, nous avons cherché à explorer l’impact des inégalités sociales et de l’environnement physique (pollution atmosphérique) sur l’issue de la grossesse (croissance foetale et risque de prématurité) indépendamment chez des femmes enceintes résidant dans des zones urbaines et rurales. Ce travail s’est appuyé sur les données issues de la cohorte bretonne mère-enfant PELAGIE, qui a inclus 3421 femmes enceintes entre 2002- 2006. Les paramètres anthropométriques et l’âge gestationnel à la naissance ont été renseignés à l’accouchement par le personnel médical. Le contexte urbain et rural breton a été caractérisé à partir de la définition des unités urbaines de l’INSEE. Les concentrations annuelles de pollution atmosphérique (dioxyde d’azote (NO2)) ont été modélisées à une échelle de 100 m à partir d’un modèle de "land-use regression" développé à l’échelle européenne. Enfin, le niveau socio-économique des IRIS a été estimé à l’aide d’un indice de désavantage social - construit à partir des données du recensement de l’INSEE et dont la validité et l’adaptabilité à des territoires à la fois urbains et ruraux a été examinée au préalable. Nos résultats suggèrent une influence délétère d’un contexte de vie socioéconomique défavorable sur la croissance intra-utérine, spécifiquement chez les femmes résidant en milieu rural. Nous avons également observé une augmentation du risque de prématurité associée à des niveaux > 16.4 μg.m-3 de NO2 dans l’air, à l’inverse, uniquement chez les femmes résidant dans des zones urbaines. Les associations entre l’exposition à la pollution atmosphérique et les marqueurs de la croissance intra-utérine, bien que sexe-spécifiques, ne semblent en revanche pas varier sensiblement suivant le gradient urbain-rural. Ce travail confirme la nécessité d’évaluer l’influence des inégalités sociales et environnementales sur le développement intra-utérin et de considérer l’importance et le rôle du contexte de vie, notamment urbain-rural, dans la formation de ces inégalités.
https://tel.archives-ouvertes.fr/tel-01308518

NNT : 2015REN1B010
tel-01308518
https://tel.archives-ouvertes.fr/tel-01308518
https://tel.archives-ouvertes.fr/tel-01308518/document
https://tel.archives-ouvertes.fr/tel-01308518/file/BERTIN_M--lanie.pdf

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
Background: Heterogeneous patterns of malaria transmission are thought to be driven by factors including host genetics, distance to mosquito breeding sites, housing construction, and socio-behavioural characteristics. Evaluation of local transmission epidemiology to characterize malaria risk is essential for planning malaria control and elimination programmes. The use of geographical information systems (GIS) techniques has been a major asset to this approach. To assess time and space distribution of malaria disease in Bandiagara, Mali, within a transmission season, data were used from an ongoing malaria incidence study that enrolled 300 participants aged under six years old ". Methods: Children's households were georeferenced using a handheld global position system. Clinical malaria was defined as a positive blood slide for Plasmodium falciparum asexual stages associated with at least one of the following signs: headache, body aches, fever, chills and weakness. Daily rainfall was measured at the local weather station. Landscape features of Bandiagara were obtained from satellite images and field survey. QGIS™ software was used to map malaria cases, affected and non-affected children, and the number of malaria episodes per child in each block of Bandiagara. Clusters of high or low risk were identified under SaTScan W software according to a Bernoulli model. Results: From June 2009 to May 2010, 296 clinical malaria cases were recorded. Though clearly temporally related to the rains, Plasmodium falciparum occurrence persisted late in the dry season. Two " hot spots " of malaria transmission also found, notably along the Yamé River, characterized by higher than expected numbers of malaria cases, and high numbers of clinical episodes per child. Conversely, the northeastern sector of the town had fewer cases despite its proximity to a large body of standing water which was mosquito habitat. Conclusion: These results confirm the existence of a marked spatial heterogeneity of malaria transmission in Bandiagara, providing support for implementation of targeted interventions. Background Malaria is one of the leading causes of morbidity and mortality in the world, with an estimated 3.3 billion people at risk of malaria [1]. The incidence of malaria worldwide is estimated to be 216 million cases per year, with 81% of these cases occurring in sub-Saharan Africa. Malaria kills approximately 655,000 people per year; 91% of deaths occur in sub-Saharan Africa [1], mostly in children under five years of age. In Mali, West Africa, malaria represents 36.5% of consultation motives in health center, it is a leading cause of morbidity and mortality children of less than five years of age and the first reason of anaemia in pregnant women [2]. Malaria transmission is seasonal. Malaria parasite transmission and clinical disease are characterized by important microgeographic variation, often between adjacent villages, households or families [3-8]. This local heterogeneity is driven by a variety of factors including human genetics [9,10], distance to potential breeding sites [11,12], housing construction
ISSN: 1475-2875

hal-01307672
https://hal-amu.archives-ouvertes.fr/hal-01307672
https://hal-amu.archives-ouvertes.fr/hal-01307672/document
https://hal-amu.archives-ouvertes.fr/hal-01307672/file/1475-2875-12-82.pdf
DOI : 10.1186/1476-072X-2-5

Éditeur(s) : Montpellier 1
Résumé : Understanding bioaccumulation mechanisms of persistent organic pollutants (POPs) is a major issue for environmental risk assessment. In this work, polychlorinated biphenyls (PCBs), a model contaminant family, has been studied in the European hake (Merluccius merluccius), a high trophic level species from the Gulf of Lions. High concentrations of PCBs were measured in hake from this area compared to those encountered in the population of the Bay of Biscay. PCB biomagnification was highlighted along its food web from marine phytoplankton, suggesting a strong influence of diet on contamination levels. The role of other biological processes was also apprehended in order to understand the high variability of observed levels. Thus, growth, sex, and also the degree of sexual maturity appear as major factors explaining the measured concentrations in fish. A PCB bioaccumulation model in the hake, based on the Dynamic Energy Budget theory (DEB), was developed. This approach is based on a bioenergetic model, reproducing the main physiological functions of an organism (feeding, growth and reproduction), coupled with a kinetic model of contaminants. The growth and evolution of contamination levels of several PCB congeners during the life of male and female hakes is satisfactorily simulated, both in the Gulf of Lions and in the Bay of Biscay, validating the processes taken into account. This combined modelling approach appears well adapted to study the fate of contaminants in fish, and paves the way for a realistic understanding of their effects on major biological functions of fish.
La compréhension des mécanismes de bioaccumulation des contaminants organiques persistants (POP) est un enjeu majeur pour l'évaluation des risques environnementaux. Lors de ce travail, le devenir d'une famille de contaminants modèles, les polychlorobiphényles (PCB), a été étudié chez une espèce de rang trophique élevé du golfe du Lion, le merlu Européen (Merluccius merluccius). Des concentrations élevées en PCB ont été mesurées dans les merlus de ce secteur en comparaison à celles rencontrées dans la population du golfe de Gascogne. La mise en évidence d'une bioamplification des PCB le long de son réseau trophique, depuis le phytoplancton marin, suggère une influence importante de l'alimentation sur les niveaux de contamination. Le rôle d'autres processus biologiques a également été appréhendé afin de comprendre la forte variabilité des niveaux observés. Ainsi, la croissance, le sexe, mais également le degré de maturité sexuel apparaissent comme des facteurs explicatifs majeurs des concentrations en PCB mesurées dans les poissons. Un modèle de bioaccumulation des PCB chez le merlu, basé sur la théorie de Budget d'Energie Dynamique (DEB), a été développé. Il s'agit d'une approche basée sur le couplage d'un modèle bioénergétique, reproduisant les principales fonctions physiologiques de l'organisme (nutrition, croissance et reproduction), avec un modèle de cinétique des contaminants. La croissance et l'évolution des niveaux de contamination de plusieurs congénères de PCB au cours de la vie des merlus mâles et femelles est simulée de manière satisfaisante, tant dans le golfe de Gascogne que dans le golfe du Lion, validant ainsi les processus pris en compte. Cette approche combinée de modélisation apparaît tout à fait adaptée à l'étude du devenir des contaminants chez les poissons, et ouvre la voie à une compréhension réaliste de leurs effets sur les grandes fonctions biologiques de ces organismes.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/2008/these-6490.pdf
http://archimer.ifremer.fr/doc/00000/6490/

Éditeur(s) : HAL CCSD Oxford University Press (OUP)
Résumé : International audience
Prostate cancer disparities have been reported in men of African descent who show the highest incidence, mortality, compared with other ethnic groups. Few studies have explored the genetic and environmental factors for prostate cancer in men of African ancestry. The glutathione-S-transferases family conjugates carcinogens before their excretion and is expressed in prostate tissue. This study addressed the role of GSTM1 and GSTT1 deletions on prostate cancer risk in populations of African descent. This multi-institutional case-control study gathered data from the Genetic Susceptibility to Environmental Carcinogens (GSEC) database, the African-Caribbean Cancer Consortium (AC3) and Men of African Descent and Carcinoma of the Prostate Consortium (MADCaP). The analysis included 10 studies (1715 cases and 2363 controls), five in African-Americans, three in African-Caribbean and two in African men. Both the GSTM1 and the GSTT1 deletions showed significant inverse associations with prostate cancer [odds ratio (OR): 0.90, 95% confidence interval (CI) 0.83-0.97 and OR 0.88, 95% CI: 0.82-0.96, respectively]. The association was restricted to Caribbean and African populations. A significant positive association was observed between GSTM1 deletion and prostate cancer in smokers in African-American studies (OR: 1.28, 95% CI: 1.01-1.56), whereas a reduced risk was observed in never-smokers (OR: 0.66, 95% CI: 0.46-0.95). The risk of prostate cancer increased across quartiles of pack-years among subjects carrying the deletion of GSTM1 but not among subjects carrying a functional GSTM1. Gene-environment interaction between smoking and GSTM1 may be involved in the etiology of prostate cancer in populations of African descent.
ISSN: 0143-3334

hal-00682901
https://hal.archives-ouvertes.fr/hal-00682901
DOI : 10.1093/carcin/bgr119
PUBMED : 21705483

Éditeur(s) : HAL CCSD Institut de Géographie Alpine
Résumé : International audience
The international symposium on «Urban Growth and Natural Hazards, in particular in Developing Countries» was held in the University Blaise Pascal, Clermont-Ferrand (France) on December 2 and 3, 1994. This meeting brought together about 70 research people, Ph.D. students, and professionals from France and 12 countries, representing universities, research agencies, as well as government and private companies. The symposium aimed to gather specialized people who are engaged and acting in programmes on hazard appraisal, risk prevention and urban management in city environment. These people aimed to compare experiences acquired in two different fields: on the one hand urban growth and its consequences, and on the other hand, natural hazards and effects, in particular in Developing Countries.Half-way through the International Decade for Natural Hazard Disaster Reduction, we strove to reconcile two points of view usually distincts: nature-oriented research and society-oriented research on hazards. These convergent approaches should merge, not only to improve knowledge of natural hazards and risks, but also to cope with hazard and risk situation on a day-basis in a city. We also choose to study both approaches in Developing Countries (DC) because most of the large cities of the world already are or will be located there in near future. In addition, city location in DC coincides with tropical areas where natural hazards are most frequent threats to life, in particular in mountains, on seashores, and on active convergent plate margins. We stress the fact that the 3 following topics are often lacking in studies which have been carried out on natural hazard appraisal and management. 1) How should we include social and economical factors, and particularly a sound analysis of vulnerability of people and values at risk ? 2) How should we cope with hazard management in large cities of Developing Countries ? 3) What is the specific task of research people in hazard case studies engaged in urban environment and management?Three themes correspond to the three sessions of the symposium. (1) Natural hazards and environmental factors : inventory, diagnostic and classification, (2) Vulnerability of urban society and environment : concepts, approaches, and classification, (3) Tools for urban risk prevention and risk management in case of crisis and catastrophes.
Ce numéro de la Revue de Géographie Alpine reprend une dizaine parmi les 41 contributions exposées par des chercheurs français et étrangers lors du colloque international « Croissance urbaine et risques naturels dans les pays en développement » qui s'est déroulé à l'Université Blaise Pascal, Clermont-Ferrand, les 2 et 3 décembre 1994. L'objectif général du colloque était de rassembler les diverses compétences existant en France et à l'étranger dans le domaine de l'évaluation et de la gestion des risques naturels et de confronter les expériences acquises à l'interface entre les villes en croissance et le champ d'action des phénomènes naturels créateurs de risques. Le colloque a donc réuni des chercheurs, des doctorants et des praticiens français et leurs collègues étrangers chargés de prévention, de gestion des risques naturels et de gestion urbaine, principalement dans les grandes villes des pays en développement (P.E.D.).Parvenus à mi-chemin de la Décennie Internationale pour la Prévention des Catastrophes Naturelles, nous avons porté des regards croisés sur les approches naturalistes et sociologiques des risques naturels. Il est maintenant nécessaire de faire converger ces approches, non seulement dans la connaissance des menaces et des risques, mais dans la gestion du risque quotidien en milieu urbain. Nous avons concentré ces approches dans les pays en développement ; en effet, le site de leurs grandes villes coïncide souvent avec le champ d'action des phénomènes naturels générateurs de risques, notamment dans la zone intertropicale et en particulier dans les marges continent ales actives (par exemple autour du Pacifique).Nous avons porté l'accent sur 3 points principaux, qui semblent en partie faire défaut dans les études et les méthodes actuellement mises en oeuvre dans la gestion des risques naturels : 1) comment prendre en compte les aspects socio-économiques, en particulier les types d'analyse des vulnérabilités ? 2) comment aborder la gestion des risques en milieu urbain dans les P.E.D. ? 3) quel rôle doit jouer le chercheur en Sciences de l'Homme, de la Société et de la Terre dans les analyses, les expertises consacrées aux risques et surtout dans leur gestion globale, à la charnière des sociétés citadines précaires et des milieux « naturels » contraignants ?Les contributions ont été regroupées, exposées et discutées lors du colloque sous forme de 3 thèmes. (1) Les phénomènes naturels créateurs de dommages (= menaces) : diagnostic, inventaire et typologie, (2) Les vulnérabilités des sociétés et des espaces urbanisés : concepts, typologie et modes d'analyse, (3) Les outils d'aide à la prévention et à la gestion du risque en milieu urbain.
Colloque international : "Croissance urbaine et risques naturels dans les pays en développement"
Clermont-Ferrand, Université Blaise Pascal, France

ISBN : 0035-1121
hal-01165252
https://hal.archives-ouvertes.fr/hal-01165252

Éditeur(s) : Actes du 6e colloque national BRG, La Rochelle, 2-3-4 octobre 2006
Résumé : Previous studies have shown heritable variation in larval developmental traits in the Pacific oyster Crassostrea gigas. In order to study the genetic consequences of production of oyster larvae in hatcheries, two factors, specific to hatcheries, were examined: the effect of discarding the smallest larvae (i.e. culling) and the effect of temperature (20°C versus 26°C). A mixed-family approach was used in order to infer the genetic composition of larval populations and family assignment, limiting possible environmental bias and allowing the study of a relatively large number of families using a limited number of larval tanks. Our results show that three multiplexed highly polymorphic microsatellite markers are a powerful tool for family assignment and, consequently, for the study of bivalve larvae genetics. Culling, by selective sieving of the smallest larvae is an advantageous practice at a phenotypic scale as it reduced variance in larval size, variance of developmental rate and time to settlement. Culling of 50% of the larval population only led to 15% less spat, showing a positive phenotypic correlation between larval growth and settlement success. However, culling represents a substantial risk for diversity loss, because it increases the variance of reproductive success among parental oysters. The effective population sizes of early settling cohorts of settlement were lower than those of later ones. Our results show that the settlement of slow growing larvae significantly contributes to minimizing the variability of reproductive success and therefore to maximizing genetic diversity. These results corroborate the low estimations of variability of broodstocks sampled in several French commercial hatcheries, relative to natural populations. The genetic composition of the larval population and the resulting spat was significantly different between the two tested temperatures, revealing genotype x environment interaction for survival. Similarly, genotype x environment interaction was also observed for larval growth as a higher temperature exerted a positive influence on the expression of genetic variability for this trait. Consequently, we can conclude that a temperature of 26°C coupled with culling, to common practice in oyster hatcheries, is likely to amplify the selection pressure for fast growing larvae. To test for this hypothesis, we compared larval developmental traits in the progeny of a hatchery broodstock closed for 7 generations, with the progeny of wild oysters and the two possible hybrids. Our results show that selection of fast growing larvae can counteract presumed inbreeding depression, due to higher mean relatedness among hatchery broodstock than in the wild. Genetic effects of intensive rearing conditions at larval stage are significant and should be taken into account in hatchery practices, especially in terms of genetic diversity management.
Afin d'étudier les conséquences génétiques des pratiques de production en écloserie d'huître creuse, deux facteurs ont été examinés : l'élimination des petites larves et la température. Nos résultats montrent que l'assignation de parenté par marqueurs microsatellites est un outil performant pour les études génétiques en phase larvaire de familles élevées en mélange. Bien qu'avantageux d'un point de vue phénotypique, le tamisage sélectif représente un risque de perte de diversité. La fixation des larves à croissance lente permet en effet de minimiser la variabilité du succès reproducteur et de fait, de maximiser la variabilité génétique. Ces résultats corroborent les estimations de variabilité sur les stocks d'écloseries françaises où l'on constate une diversité allélique inférieure à celle de populations issues du milieu naturel. La température exerce également une influence sur la précocité de l'expression de la variabilité génétique pour la croissance larvaire. Ainsi une température élevée associée à une procédure de tamisage peut amplifier l'effet sélectif. Enfin, la sélection de larves à croissance rapide semble démontrée, s'opposant à la dépression de consanguinité présumée. Les conditions d'élevage peuvent donc avoir un effet génétique significatif qui devrait être pris en considération dans les pratiques d'écloserie, notamment dans la gestion de la diversité génétique.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/2006/acte-1505.pdf
http://archimer.ifremer.fr/doc/00000/1505/

Éditeur(s) : HAL CCSD BMJ Publishing Group
Résumé : International audience
BACKGROUND: The association between lung cancer and occupational exposure to organic solvents is discussed. Since different solvents are often used simultaneously, it is difficult to assess the role of individual substances. OBJECTIVES: The present study is focused on an in-depth investigation of the potential association between lung cancer risk and occupational exposure to a large group of organic solvents, taking into account the well-known risk factors for lung cancer, tobacco smoking and occupational exposure to asbestos. METHODS: We analysed data from the Investigation of occupational and environmental causes of respiratory cancers (ICARE) study, a large French population-based case-control study, set up between 2001 and 2007. A total of 2276 male cases and 2780 male controls were interviewed, and long-life occupational history was collected. In order to overcome the analytical difficulties created by multiple correlated exposures, we carried out a novel type of analysis based on Bayesian profile regression. RESULTS: After analysis with conventional logistic regression methods, none of the 11 solvents examined were associated with lung cancer risk. Through a profile regression approach, we did not observe any significant association between solvent exposure and lung cancer. However, we identified clusters at high risk that are related to occupations known to be at risk of developing lung cancer, such as painters. CONCLUSIONS: Organic solvents do not appear to be substantial contributors to the occupational risk of lung cancer for the occupations known to be at risk
ISSN: 1351-0711

hal-01282444
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01282444
DOI : 10.1136/oemed-2015-103177
PUBMED : 26911986

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Few studies have explored the consequences of environmental exposure to organochlorine pesticides for gestational hypertension (GH), preeclampsia (PE) and gestational diabetes mellitus (GDM). Chlordecone is a persistent organochlorine pesticide that was used intensively, and almost exclusively, in the French West Indies until 1993. We investigated the impact of prenatal exposure to chlordecone on the occurrence of GDM, GH and PE by studying 779 pregnant women enrolled in a prospective mother-child cohort (Timoun Study) in Guadeloupe between 2004 and 2007. Chlordecone exposure was determined by assaying maternal plasma and information about pregnancy complications was obtained from midwives, pediatricians and hospital medical records after delivery. The risks of GH (n=65), PE (n=31) and GDM (n=71) were estimated by multiple logistic regression including potential confounders. Levels of chlordecone plasma concentration in the third (OR=0.2; 95% confidence interval (CI): 0.1, 0.5) and fourth quartiles (OR=0.3; 95% CI: 0.2, 0.7) were associated with a statistically significant decrease in the risk of GH. A log10 increase in chlordecone concentration was significantly associated with lower risk of GH (OR=0.4; 95% CI: 0.2, 0.6). No significant associations were observed between the chlordecone exposure and the risk of PE or GDM. This study suggests an inverse association between chlordecone exposure during pregnancy and GH. Further studies are required to determine the underlying mechanism, or the potential unknown confounding factors, resulting in this association.
ISSN: 0160-4120

hal-01061391
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01061391
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01061391/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01061391/file/Saunders_et_al._Final_version_main_manuscript.pdf
DOI : 10.1016/j.envint.2014.03.024

Éditeur(s) : HAL CCSD
Résumé : National audience
Objective of the study An estimation of burden of serious fungal diseases in France is essential data to inform public health priorities on the importance of resources and research needed on these infections. In France, precise data are available for invasive fungal diseases but estimates for several other diseases such as chronic and immunoallergic diseases are by contrast less known. Materials and methods A systematic literature search was conducted using the Web of Science Platform. Published epidemiology papers reporting fungal infection rates from France were identified. Where no data existed, we used specific populations at risk and fungal infection frequencies in those populations to estimate national incidence or prevalence, depending on the condition. Results The model predicts high prevalences of severe asthma with fungal sensitization episodes (189 cases/100,000 adults per year), of allergic bronchopulmonary aspergillosis (145/100,000) and of chronic pulmonary aspergillosis (5.24/100,000). Besides, estimated incidence for invasive aspergillosis is 1.8/100,000 annually based on classical high risk factors. Estimates for invasive mucormycosis, pneumocystosis and cryptococcosis are 0.12/100,000, 1/100,000 and 0.2/100,000, respectively. Regarding invasive candidiasis, more than 10,000 cases per year are estimated, and a much higher number of recurrent vaginal candidiasis is probable but must be confirmed. Finally, this survey was an opportunity to report a first picture of the frequency of tinea capitis in France. Conclusion Using local and literature data of the incidence or prevalence of fungal infections, approximately 1,000,000 (1.47%) people in France are estimated to suffer from serious fungal infections each year. © 2016 Elsevier Masson SAS
Journal de Mycologie Medicale

hal-01467554
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01467554
DOI : 10.1016/j.mycmed.2016.11.001
PUBMED : 27887809

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
BACKGROUND: Few studies have considered using environmental amenities to explain social health inequalities.Nevertheless, Green spaces that promote good health may have an effect on socioeconomic health inequalities. In developed countries, there is considerable evidence that green spaces have a beneficial effect on the health of urban populations and recent studies suggest they can have a positive effect on pregnancy outcomes. To investigate the relationship between green spaces and the spatial distribution of infant mortality taking account neighborhood deprivation levels. METHODS: The study took place in Lyon metropolitan area, France. All infant deaths that occurred between 2000 and 2009 were geocoded at census block level. Each census block was assigned greenness and socioeconomic deprivation levels. The spatial--scan statistic was used to identify high risk cluster of infant mortality according to these neighborhood characteristics. RESULTS: The spatial distribution of infant mortality was not random with a high risk cluster in the south east of the Lyon metropolitan area (p<0.003). This cluster disappeared (p=0.12) after adjustment for greenness level and socioeconomic deprivation, suggesting that these factors explain part of the spatial distribution of infant mortality. These results are discussed using a conceptual framework with 3 hypothetical pathways by which green spaces may have a beneficial effect on adverse pregnancy outcomes: (i) a psychological pathway, (ii) a physiological disruption process and (iii) an environmental pathway. CONCLUSIONS: These results add some evidence to the hypothesis that there is a relationship between access to green spaces and pregnancy outcomes but further research is required to confirm this.
ISSN: 1471-2393

inserm-00878362
http://www.hal.inserm.fr/inserm-00878362
http://www.hal.inserm.fr/inserm-00878362/document
http://www.hal.inserm.fr/inserm-00878362/file/1471-2393-13-191.pdf
DOI : 10.1186/1471-2393-13-191

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
The CoPanFlu-France cohort of households was set up in 2009 to study the risk factors for infection by the pandemic influenza virus (H1N1pdm) in the French general population. The authors developed an integrative data-driven approach to identify individual, collective and environmental factors associated with the post-seasonal serological H1N1pdm geometric mean titer, and derived a nested case-control analysis to identify risk factors for infection during the first season. This analysis included 1377 subjects (601 households). The GMT for the general population was 47.1 (95% confidence interval (CI): 45.1, 49.2). According to a multivariable analysis, pandemic vaccination, seasonal vaccination in 2009, recent history of influenza-like illness, asthma, chronic obstructive pulmonary disease, social contacts at school and use of public transports by the local population were associated with a higher GMT, whereas history of smoking was associated with a lower GMT. Additionally, young age at inclusion and risk perception of exposure to the virus at work were identified as possible risk factors, whereas presence of an air humidifier in the living room was a possible protective factor. These findings will be interpreted in light of the longitudinal analyses of this ongoing cohort.
ISSN: 1932-6203

Droits : http://creativecommons.org/licenses/by-sa/
hal-01122215
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01122215
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01122215/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01122215/file/journal.pone.0060127.pdf
PUBMED : 23613718

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
BACKGROUND: Few studies have considered using environmental amenities to explain social health inequalities.Nevertheless, Green spaces that promote good health may have an effect on socioeconomic health inequalities. In developed countries, there is considerable evidence that green spaces have a beneficial effect on the health of urban populations and recent studies suggest they can have a positive effect on pregnancy outcomes. To investigate the relationship between green spaces and the spatial distribution of infant mortality taking account neighborhood deprivation levels. METHODS: The study took place in Lyon metropolitan area, France. All infant deaths that occurred between 2000 and 2009 were geocoded at census block level. Each census block was assigned greenness and socioeconomic deprivation levels. The spatial--scan statistic was used to identify high risk cluster of infant mortality according to these neighborhood characteristics. RESULTS: The spatial distribution of infant mortality was not random with a high risk cluster in the south east of the Lyon metropolitan area (p<0.003). This cluster disappeared (p=0.12) after adjustment for greenness level and socioeconomic deprivation, suggesting that these factors explain part of the spatial distribution of infant mortality. These results are discussed using a conceptual framework with 3 hypothetical pathways by which green spaces may have a beneficial effect on adverse pregnancy outcomes: (i) a psychological pathway, (ii) a physiological disruption process and (iii) an environmental pathway. CONCLUSIONS: These results add some evidence to the hypothesis that there is a relationship between access to green spaces and pregnancy outcomes but further research is required to confirm this.
BMC Pregnancy and Childbirth

hal-00876083
https://hal.archives-ouvertes.fr/hal-00876083
https://hal.archives-ouvertes.fr/hal-00876083/document
DOI : 10.1186/1471-2393-13-191

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
UNLABELLED: ABSTRACT: BACKGROUND: Malaria is a major health issue in French Guiana. Amerindian communities remain the most affected. A previous study in Camopi highlighted the predominant role of environmental factors in the occurrence of malaria. However, all parameters involved in the transmission were not clearly identified. A new survey was conducted in order to clarify the risk factors for the presence of malaria cases in Camopi. METHODS: An open cohort of children under seven years of age was set up on the basis of biologically confirmed malaria cases for the period 2001-2009. Epidemiological and observational environmental data were collected using two structured questionnaires. Data were analysed with a multiple failures multivariate Cox model. The influence of climate and the river level on malaria incidence was evaluated by time-series analysis. Relationships between Anopheles darlingi human biting rates and malaria incidence rates were estimated using Spearman's rank correlation. RESULTS: The global annual incidence over the nine-year period was 238 per 1,000 for Plasmodium falciparum, 514 per 1,000 for Plasmodium visa and 21 per 1,000 for mixed infections. The multivariate survival analysis associated higher malaria incidence with living on the Camopi riverside vs. the Oyapock riverside, far from the centre of the Camopi hamlet, in a home with numerous occupants and going to sleep late. On the contrary, living in a house cleared of all vegetation within 50 m and at high distance of the forest were associated with a lower risk. Meteorological and hydrological characteristics appeared to be correlated with malaria incidence with different lags. Anopheles darlingi human biting rate was also positively correlated to incident malaria in children one month later. CONCLUSIONS: Malaria incidence in children remains high in young children despite the appearance of immunity in children around three years of age. The closeness environment but also the meteorological parameters play an important role in malaria transmission among children under seven years of age in Camopi.
ISSN: 1475-2875

inserm-00633771
http://www.hal.inserm.fr/inserm-00633771
http://www.hal.inserm.fr/inserm-00633771/document
http://www.hal.inserm.fr/inserm-00633771/file/1475-2875-10-246.pdf
DOI : 10.1186/1475-2875-10-246

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Introduction Evidence has accumulated that exposure to ambient air pollution during pregnancy may influence preterm birth (PTB) in urban settings. Conversely, this relation has barely been investigated in rural areas where individual characteristics (demographic, socioeconomic, and psychosocial factors) and environmental co-exposures may differ. Objective We examined the association between prenatal exposure to traffic-related air pollution and PTB among pregnant women from the PELAGIE mother–child cohort (Brittany, France, 2002–2006) living in urban (n=1550) and rural (n=959) settings. Methods Women’s residences were classified as either urban or rural according to the French census bureau rural–urban definitions. Nitrogen dioxide (NO2) concentrations at home addresses were estimated from adjusted land-use regression models as a marker of traffic-related pollution. Associations between NO2 concentrations and PTB were assessed with logistic regression models. Results Prevalence of PTB was similar among women living in urban (3.2%) and in rural (3.5%) settings. More positive socioeconomic characteristics and health behaviors but more single-parent families were observed among urban women. NO2 exposure averaged 20.8±6.6 µg m−3 for women residing in urban areas and 18.8±5.6 µg m−3 for their rural counterparts. A statistically significant increased risk of PTB was observed among women exposed to NO2 concentrations ≥16.4 µg m−3 and residing in urban areas but not among their rural counterparts. Discussion The results of this study, conducted in a region with interspersed urban–rural areas, are in line with previous findings suggesting an increased risk of PTB associated with higher NO2 concentrations for women living in urban areas. The absence of association among their rural counterparts for whom exposure levels were similar suggests that environmental mixtures and psychosocial inequalities might play a role in this heterogeneity
ISSN: 0013-9351

hal-01165108
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01165108
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01165108/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01165108/file/Air%20pollution%20%26%20preterm%20birth%20PELAGIE_HAL-accepted.pdf
PUBMED : 26092808

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Humans are exposed to a large number of contaminants, many of which may have similar health effects. This paper presents a framework for identifying pollutants to be included in a cumulative risk assessment approach. To account for the possibility of simultaneous exposure to chemicals with common toxic modes of action, the first step of the traditional risk assessment process, i.e. hazard identification, is structured in three sub-steps: (1a) Identification of pollutants people are exposed to, (1b) identification of effects and mechanisms of action of these pollutants, (1c) grouping of pollutants according to similarity of their mechanism of action and health effects. Based on this exposure-based grouping we can derive "multi-pollutant" toxicity reference values, in the "dose-response assessment" step. The approach proposed in this work is original in that it is based on real exposures instead of a limited number of pollutants from a unique chemical family, as traditionally performed. This framework is illustrated by the case study of semi-volatile organic compounds in French dwellings, providing insights into practical considerations regarding the accuracy of the available toxicological information. This case study illustrates the value of the exposure-based approach as opposed to the traditional cumulative framework, in which chemicals with similar health effects were not always included in the same chemical class.
ISSN: 0013-9351

hal-00982315
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00982315
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00982315/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00982315/file/An_exposure-based_framework_for_grouping_pollutants_accepted.pdf
DOI : 10.1016/j.envres.2014.01.007

Éditeur(s) : HAL CCSD BMJ Publishing Group
Résumé : For the ICARE Study Group
International audience
Objective Our objective was to investigate the association between head and neck cancer and occupational exposure to chlorinated, oxygenated and petroleum solvents in women.Methods Investigation of occupational and environmental CAuses of REspiratory cancers (ICARE), a French population-based case–control study, included 296 squamous cell carcinomas of the head and neck (HNSCC) in women and 775 female controls. Lifelong occupational history was collected. Job-exposure matrices allowed to assess exposure to 5 chlorinated solvents (carbon tetrachloride; chloroform; methylene chloride; perchloroethylene; trichloroethylene), 5 petroleum solvents (benzene; special petroleum product; gasoline; white spirits and other light aromatic mixtures; diesel, fuels and kerosene) and 5 oxygenated solvents (alcohols; ketones and esters; ethylene glycol; diethyl ether; tetrahydrofuran). OR and 95% CIs, adjusted for smoking, alcohol drinking, age and geographical area, were estimated with logistic models.Results Elevated ORs were observed among women ever exposed to perchloroethylene (OR=2.97, 95% CI 1.05 to 8.45) and trichloroethylene (OR=2.15, 95% CI 1.21 to 3.81). These ORs increased with exposure duration (OR=3.75, 95% CI 0.64 to 21.9 and OR=4.44, 95% CI 1.56 to 12.6 for 10 years or more, respectively). No significantly increased risk of HNSCC was found for occupational exposure to the other chlorinated, petroleum or oxygenated solvents.Conclusions These findings suggest that exposure to perchloroethylene or trichloroethylene may increase the risk of HNSCC in women. In our study, there is no clear evidence that the other studied solvents are risk factors for HNSCC.
ISSN: 2044-6055

Droits : http://creativecommons.org/licenses/by-nc/
hal-01438872
http://hal.upmc.fr/hal-01438872
http://hal.upmc.fr/hal-01438872/document
http://hal.upmc.fr/hal-01438872/file/e012833.full.pdf
DOI : 10.1136/bmjopen-2016-012833

Éditeur(s) : HAL CCSD
Résumé : International audience
OBJECTIVE: Contemporary pesticides, such as triazines or organophosphates, possess immunotoxic properties. We aimed to determine whether prenatal environmental exposure to these current-use pesticides was associated with otitis media (OM) during the first 2 years of life among children from the PELAGIE mother-child cohort. METHODS: The PELAGIE cohort enrolled 3421 women at the beginning of pregnancy in Brittany (France). At the 2-year follow-up, 1505 families completed a self-administered questionnaire, including the domestic use of pesticides and consumption of organic diet during pregnancy and occurrences of OM in the child. Two health outcomes were considered: at least one OM and recurrent OM (at least three). Multivariate logistic regression models that adjusted for known risk factors of OM were performed. Metabolites of triazine herbicides and organophosphate insecticides measured in urine collected before the 19th week of gestation (248 mothers) were considered in a subgroup analysis. Multiple imputation was used to handle missing values for the covariates. RESULTS: Children whose mothers reported an organic diet during pregnancy had a reduced risk of OM (at least one episode, p trend=0.01). No association was found between any outcome and residential proximity to crops. The presence in maternal urine of dealkylated triazine metabolites (OR=2.12 (1.01 to 4.47)) was positively associated with recurrent OM. CONCLUSIONS: To the best of our knowledge, this is the first work to suggest a positive association between prenatal exposure to current-use pesticides and the occurrence of parent-reported OM in young children
Occupational and Environmental Medicine

hal-01201944
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01201944
DOI : 10.1136/oemed-2015-103039
PUBMED : 26347056