There exist potential health risks due to the presence of some elements in groundwater. This study presents measurements of gross alpha and beta activity and chemical concentrations (fluorides and nitrates) in 25 water wells in Aldama municipality, Chihuahua, Mexico. Total alpha and beta emitter analyses were performed at the Academic Unit of Nuclear Studies at the Autonomous University of Zacatecas. Radioactive elements were concentrated by total evaporation. All samples were measured with a Wallac-Oy 1411 liquid scintillate with a pulse separation option (Pulse Shape Analysis) for 6 h. Fluorine and nitrate analyses were performed at the Faculty of Engineering of the Autonomous University of Chihuahua by flow injection-hydride generation collection-atomic absorption spectrometry. Exposure levels were calculated for each well and found to exceed maximum limits allowed under Mexican law in terms of 1) gross alpha and beta activity; and 2) fluoride and nitrate concentrations. Gross alpha activity in two wells exceeded the reference value of 0.56 Bq•L −1. Fluorides and nitrates were found in 40% and 48% of water wells, respectively. Fluoride values were higher than 1.5 mg•L −1 , and the exposure doses for adults and children exceeded the reference value of 0.06 mg•kg −1 •d −1. Children are the most vulnerable, since their intake doses are near or above of 0.12 mg•kg −1 •d −1 of the minimum level of risk for the development of skeletal fluorosis or bone fractures. On the other hand, while nitrate concentrations in water wells exceeded the drinking water limit of 10 mg•L −1 , this does not represent a serious health risk, since the calculated exposure doses for adults and children are below the chronic reference level of 1.6 mg•kg −1 •d −1 established by the USEPA.

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Groundwater is a strategic resource for economic development, social justice, environmental sustainability, and water governance. The Lower Casas Grandes Basin located in the state of Chihuahua, Mexico is in a semi-arid region that has increasing groundwater demands while confronting regional challenges such as adverse climate change scenarios and depleting aquifers. Even though there is official information about the availability of groundwater, comprehensive aquifer characterization is still uncertain and needs interdisciplinary investigation using a diverse suite of tools and multiple data sources. This study presents a multi-technique framework to evaluate potential sites to drill for groundwater resources. The main components of the methodology included: wellhead leveling correction with a differential global positioning survey to define piezometric levels, principal component analysis using Landsat-8 images, application of geospatial tools, geophysics using Time Domain Electromagnetic Surveys and Vertical Electric Soundings and structural geohydrology to define aquifer characteristics. Results show that the application of the framework enhances the possibility of successful drilling for groundwater while saving time and money using “pin-point” positioning for drilling sites as compared to a traditional extensive groundwater exploration approach. Low resistivity values (35 Ohm-m) were found at depths from 50m to 85m at sites where the regional static water level reached 245 m deep adding a shallow groundwater potential at sites where the intersection of fracture trace was identified. This procedure can be used at other sites where limited or minimum information is available for groundwater exploration to reduce the risk of drilling dry wells in complex hydrogeological environments.

La radiación en aguas termales utilizadas como zonas recreativas puede representar un problema de salud pública. El objetivo fue cuantificar el nivel de radón (222Rn) en aire y evaluar la dosis de radiación en los baños termales establecidos en San Diego de Alcalá, Chihuahua, México. Se seleccionó un espacio de esparcimiento, se cerró puerta y ventana para simular la utilización del baño termal por el público. El nivel de 222Rn en aire se detectó utilizando un instrumento AlphaGUARD (Professional Radon Monitor) de la marca GENITRON. Éste se cuantificó en Bq m-3 en diferentes tiempos 10, 20, 30, 40, 50 y 60 min, se realizaron tres mediciones; la primera en la epoca de invierno 2014 (enero) y dos en la epoca de primavera de 2015 (mayo y junio). El análisis estadístico fue mediante una regresión para cada medición. Se estimó la Dosis Promedio Anual (DPA) efectiva de inhalación de radón a la que se encuentran expuestas las personas que acuden a los baños termales dependiendo del número de visitas y tiempo de permanencia, el rango varió de 0.0005±4x10-4 mSv cuando se visitan los baños 12 veces al año con un permanencia de 10 minutos, hasta 0.0352±1.1x10-2 mSv visitando una vez a la semana por un periodo de 60 minutos.

Arsenic and fluorine occur naturally in groundwater, especially in desert and semi-desert areas. Chronic exposure through drinking water to these substances causes adverse health effect, which are limited in water intended for human consumption. Objective: This work was carried out with the aim of improving the quality of water from wells with high contents of arsenic and fluorine, achieving compliance with the limits established in the Mexican regulations for drinking water. Methodology: A system of two-panel solar distillation was used for treatment of water from three wells characterized by high levels of arsenic and fluoride, which are intended for human consumption. Contribution: The solar distillation system used improved the quality of the groundwater through the removal of arsenic (99%), fluoride (96%) and dissolved solids (98%). The proven system is a viable alternative for water treatment in small communities that do not have access to demineralization water plants that operate with high costs, thus eliminating health risks associated to the chronic intake of these elements.