Banned or restricted organochlorine pesticides in many countries worldwide are still in use in developing countries for agricultural and livestock activities, as well as for vector control in public health campaigns. The present study was conducted to map estimated concentrations of organochlorine pesticides in a karstic region in the Yucatan Peninsula, Mexico, known as ‘Ring of Cenotes’. Water samples from 20 sinkholes (‘cenotes’) were collected during the dry and rainy seasons in 2010–11, analysed by gas chromatography and maps of pesticide concentrations were produced using geographical information system. Results show the presence of banned pesticides, all of them exceeding the limits stated by the Mexican Official Norm. The number and concentration of pesticides during the dry season were qualitatively and quantitatively higher than in the rainy season. The spatial distribution of pesticide concentrations shows that causes of pesticide pollution in the aquifer of the Ring of Cenotes are multifactorial.
Abstract:The expanded use of macrocyclic lactones (ML) to treat endo-and ectoparasites in cattle in tropical regions, can reduce dung beetle populations, and thus interrupt the dung removal process in cattle pasture ecosystems. During the reproductive period (the rainy season) of two functional groups of dung beetles (paracoprid and telocoprid Scarabaeinae), we compared dung removal amount in ranches where ML are and are not used in Yucatan, Mexico, through exclusion traps baited with 500 g of ML-free cow dung. On each ranch, two transects (separated by 500 m) with six traps each, were set up for 24 hours. After this time, all the dung remnants in each trap were obtained and weighed in order to record the dung removal. Results showed that dung removal amounts were similar in ranches with and without ML use. Dung beetles removed 40.1 % of all cow dung weighed. Paracoprids removed 87.46 % and telocoprids 12.54 % of all the dung that was removed. Our results indicated that the ecological function of dung beetles in the pastures studied, does not seem to be affected by the ML use, and that paracoprid species removed most of the dung. For both types of ranch, further studies that take into account the population dynamics and movement of the most important dung beetle species in the region are required, coupled with laboratory studies evaluating the effect of ML on their reproductive success. This could give some light on the effect of ML on the ecological function of this important insect group in the sustainability of cattle production systems. Rev. Biol. Trop. 64 (3): 945-954. Epub 2016 September 01.
Water quality is an essential ecological value for health and economic growth. In Peru, due to its mineralogical nature by the presence of the Andean Mountain System and its economy dependent on the extraction of minerals, conditions exist for the dispersion of chemical contaminants, especially metals, which can reach the drinking water, causing a generalized exposure of the population to a chronic risk that is already becoming unmanageable. Pollution of watersheds exposes people to cadmium in the northern part of the country, to lead in the central regions, and to arsenic in the south. Physical-chemical treatment is becoming increasingly expensive for drinking water companies. In this context, the socio-environmental conflicts have evidence through the presence of heavy metals in the blood that is enough to generate adverse climates for the economy and delay in investments, resulting in a vicious circle that is difficult to resolve. The analysis of the two causes: mineralogical nature and mining extraction, must be deepened to achieve an adequate solution that prioritizes people's health, but also promotes investments for economic growth. The objective of this review is to motivate Health Authorities to address the problem and to develop risk communication strategies so that the problem can be addressed in a cost-effective manner through health education, while at the same time continuing to make progress in the development of more eco-efficient mining technologies.
<p>Actualmente, el sistema conformado por la ciudad de Corrientes y los centros urbanos y rurales próximos de los municipios de Santa Ana, Riachuelo, San Luis del Palmar, Paso de la Patria y San Cosme, con los que mantiene una fuerte interrelación funcional y económica, evidencia un gran desequilibrio tanto en peso poblacional como en complejidad de las actividades urbanas. Esta situación evidencia un proceso de expansión dispersa de la ciudad Capital, donde la localización de las actividades productivas; la escasa conectividad; la incorporación de suelo periurbano y rural; los desarrollos residenciales en áreas peri-urbanas, han conformando una compleja sucesión de espacios de transición entre lo urbano y lo rural.<br />En este marco, el trabajo apunta a evidenciar variaciones y tendencias en la localización de la población en la capital y su área de influencia directa, relacionándolas con las formas de ocupación, los cambios de usos de suelo y el fenómeno de movilidad residencial, de manera tal que permitan visibilizar la configuración procesos de metropolización y micro regionalización, con vista a la definición de criterios para la planificación y ordenamiento territorial del espacio de estudio.<br /><br /><br /></p>
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