Utilidad de los registros sanitarios locales para vincular la tasa de incidencia de diarreas con la calidad del agua de consumo / Usefulness of local health reports to link the incidence rate of diarrhea with the quality of drinking water

En este trabajo se realizó un relevamiento de los informes del centro de salud ubicado en Vaqueros (Salta, Argentina) durante un período de 8 meses. Al mismo tiempo se determinó la concentración de Escherichia coli y de quistes de Giardia spp. en muestras procedentes de cuatro fuentes de agua diferentes. No se encontró una relación estadísticamente significativa entre la calidad del agua y los casos de diarrea. Sin embargo, mediante un cálculo de odds ratios, se pudo determinar que uno de los sistemas de potabilización estudiados actúa como factor de protección contra diarreas. El presente trabajo brinda información útil para la planificación de medidas preventivas por parte del sistema de salud local.

In this study, we analyzed the reports of the health care center located in Vaqueros (Salta, Argentina) over an 8-month period. Moreover, we determined the concentration of Escherichia coli and Giardia spp. cysts in samples from four different drinking water sources. A statistical relationship between water quality and cases of diarrhea could not be found. However, using an odds ratio calculation, it was possible to determine that one of the studied drinking water systems acts as a protection factor in cases of diarrhea. The present work provides useful information for planning preventive measures by the local health system.

Caracterización espacial y estacional del agua de consumo proveniente de diversas fuentes en una localidad periurbana de Salta / Spatial and seasonal characterization of the drinking water from various sources in a peri-urban town of Salta

El control del agua de consumo es importante, ya sea que esta provenga de sistemas de potabilización o que carezca de tratamiento previo. El acceso creciente a agua potabilizada ha sido monitorizado a lo largo de los últimos anos a fin de alcanzar los denominados «Objetivos de desarrollo del milenio¼, cuyo plazo se cumplió en 2015. De cara al futuro, los llamados «Objetivos de desarrollo sostenible¼, que se han propuesto para el año 2030, buscan garantizar el acceso a agua segura de toda la población mundial. En el marco de estas metas mundiales, es importante la monitorización de los sistemas locales. En este trabajo se estudió una población que cuenta con diferentes sistemas de provisión de agua de consumo, que incluyen o no el tratamiento de aquella. Se realizó la monitorización de todos los indicadores microbiológicos regidos por el Código Alimentario Argentino y de diversas variables fisicoquímicas, a fin de diferenciar los sitios de muestreo de acuerdo con la influencia de la estacionalidad, el tipo de fuente de provisión de agua y la correlación entre las variables microbiológicas y las fisicoquímicas. Se observó que el agua proveniente de fuentes con tratamiento presentó desviaciones en algunas de sus variables en época de lluvias, mientras que las fuentes sin tratamiento no cumplieron con los requerimientos bacteriológicos en forma permanente. Este estudio pone de manifiesto la importancia de reevaluar los sistemas de potabilización, que deberían garantizar su eficacia de manera constante, así como la inmediata necesidad de desarrollar nuevos sistemas de tratamiento para dar solución a la población que aún no cuenta con agua de consumo segura.

Drinking water monitoring plans are important to characterize both treated and untreated water used for drinking purposes. Access to drinking water increased in recent years as a response to the Millennium Development Goals set for 2015. The new Sustainable Development Goals aim to ensure universal access to safe drinking water by 2030. Within the framework of these global goals, it is crucial to monitor local drinking water systems. In this paper, treated and untreated water from different sources currently consumed in a specific town in Salta, northern Argentina, was thoroughly assessed. Monitoring extended along several seasons and included the physical, chemical and microbiological variables recommended by the Argentine Food Code. On the one hand, treated water mostly complies with these standards, with some non-compliances detected during the rainy season. Untreated water, on the other hand, never meets microbiological standards and is unfit for human consumption. Monitoring seems essential to detect anomalies and help guarantee a constant provision of safe drinking water. New treatment plants are urgently needed to expand the water grid to the entire population.

Comparación de índices bióticos utilizados en el monitoreo de dos sistemas lóticos del noroeste argentino / Comparison of biotic index used in monitoring of 2 lotic systems in north-western Argentina

Two lotic bodies located in a subtropical semi-arid region in north-western Argentina were studied: the Arias-Arenales and the Rosario rivers. Both rivers are located in Salta Province, and belong to the high basin of river Juramento, connected to the river RÝo de la Plata and the Atlantic Ocean. The study was conducted between March 1997 and March 1998. The region is known by its sustained economic development and one of the highest population growth rates in the country (4 per year). The objective of this work was the assessment of organic pollution spatial gradients in both rivers, as a function of the hydrological regime (a long period of drought from May to October and floodings the rest of the year). Three groups of biotic indices were applied to characterize the level of organic pollution and were based on planktonic microalgae to evaluate water quality. The relative performance of these indices was then compared for use to biomonitoring programs. The diversity indices: Shannon-Weaver and Whilm-Dorris were not highly sensible to detect moderate pollution. The saprobity indices (Pantle and Buck and Diatom Assemblage Index of Watanabe et al.), were useful to detect intermediate levels of organic load, but their sensitivity dropped at high pollution levels. The second index precisely discriminated the most deteriorated part of river Rosario, with values between 0.3-0.7 (extreme poli-saprobity). Raw sewage discharges along the most polluted sector of river Arias-Arenales were assigned a value between 10 and 11 in both periods of the hydrological regime. Both saprobity indices consider the same indicator pollution value of species. The first one is based on the relative abundance of the species while the second one is calculated with the species relative frequency. The second index is better than the first one in considering non-dominant species that were constant in each particular environmental condition. The principal component analysis allowed a representation of time and space pollution patterns and showed the specific microalgae assemblage for all the sampling stations and for both periods in the hydrological cycle. Only the latter proved to be fully useful and correct for the biological characterization of water quality system.