The importance of greater control over environmental risk and educational factors needs to be emphasized in attempts to reduce the prevalence of these parasitic diseases.

The role of irrigated areas for the spread of schistosomiasis is of worldwide concern. The aim of the present study was to investigate the spatial distribution of the intermediate snail host Biomphalaria in an area highly endemic for schistosomiasis due to Schistosoma mansoni, evaluating the relationship between irrigation and types of natural water sources on one hand, and the influence of place and time of water exposure on the intensity of human infection on the other. A geographical information system (GIS) was used to map the distribution of the intermediate snail hosts in Ilha das Flores, Sergipe, Brazil, combined with a clinical/epidemiological survey. We observed a direct correlation between the intensity of human infection with S. mansoni and irrigation projects. Malacological studies to identify snail species and infection rates showed that B. glabrata is the main species responsible for human schistosomiasis in the municipality, but that B. straminea also plays a role. Our results provide evidence for a competitive selection between the two snail species in rice fields with a predominance of B. glabrata in irrigation systems and B. straminea in natural water sources.

Geospatial analysis was used to study the epidemiology of Schistosoma mansoni, intestinal parasites and co-infections in an area (Ilha das Flores) in Sergipe, Brazil. We collected individually georeferenced sociodemographic, behavioral and parasitological data from 500 subjects, analyzed them by conventional statistics, and produced risk maps by Kernel estimation. The prevalence rates found were: S. mansoni (24.0%), Trichuris trichiura (54.8%), Ascaris lumbricoides (49.2%), Hookworm (17.6%) and Entamoeba histolytica (7.0%). Only 59/500 (11.8%) individuals did not present any of these infections, whereas 279/500 (55.8%) were simultaneously infected by three or more parasites. We observed associations between S. mansoni infection and various variables such as male gender, being rice farmer or fisherman, low educational level, low income, water contact and drinking untreated water. The Kernel estimator indicated that high-risk areas coincide with the poorest regions of the villages as well as with the part of the villages without an adequate sewage system. We also noted associations between both A. lumbricoides and hookworm infections with low education and low income. A. lumbricoides infection and T. trichiura infection were both associated with drinking untreated water and residential open-air sewage. These findings call for an integrated approach to effectively control multiple parasitic infections.

The environmental impact assessment process is over 40 years old and has dramatically expanded. Topics, such as social, health and human rights impact are now included. The main body of an impact analysis is generally hundreds of pages long and supported by countless technical appendices. For large, oil/gas, mining and water resources projects both the volume and technical sophistication of the reports has far exceeded the processing ability of host communities. Instead of informing and empowering, the reports are abstruse and overwhelming. Reinvention is required. The development of a visual integrated impact assessment strategy that utilizes remote sensing and spatial analyses is described.

RESUMOA erosão do solo é a principal causa do empobrecimento precoce de terras produtivas e dentre as suas formas está a erosão laminar. Esta se caracteriza não apenas pela remoção de uma camada relativamente uniforme da superfície, mas também por seus nutrientes, sendo intensificada, portanto, pelas ações antrópicas. Para evitar ou reduzir seus impactos, fazem-se necessárias diretrizes para a adequação do uso e da ocupação às condições de cobertura vegetal, tipo de solo e topografia, através de mapas do potencial erosivo laminar da região de interesse, obtidos via sistemas de informações geográficas (SIG). Neste trabalho foi desenvolvido o mapeamento do potencial erosivo laminar da bacia do rio Japaratuba, SE (1685 km 2 ); trata-se de uma região sujeita a intensa atividade agrícola, pecuária e de mineração, onde só restam 6% da vegetação nativa. Os resultados mostram que 48,71% da área da bacia ficam nas classes de médio e alto potencial erosivo, indicando que a bacia está bastante impactada devido aos usos inadequados para as condições de solo e declividades. Palavras-chave: potencial erosivo, impactos antrópicos, perda de soloMapping the laminar erosion potential for the Japaratuba River Basin, SE via GIS ABSTRACT Soil erosion is a natural phenomenon that reduces soil fertility and causes a great impact on agricultural areas. Laminar erosion is characterized by the removal of the top soil fairly uniformly as well as its nutrients, which is accelerated by human activities. To minimize the impacts it is necessary to adopt an adequate soil management that takes into account the type of the soil, relief, and vegetation cover. The soil management can be aided by mapping the erosive potential of a region using GIS tools. In this work, the technique that was used for mapping the erosive potential in the Japaratuba River Basin (1685 km 2 ) located in the State of Sergipe is presented. The results show that 48.71% of the basin area lie within medium and high erosive potentials zones, suggesting the inadequate land use for the soil types and relief within the basin.