Arsenic contamination of drinking water remains a persistent global health burden and an environmental justice challenge, particularly for low-resource communities that lack access to reliable monitoring tools. Synthetic-biology-driven biosensors offer a promising complement to conventional analytical methods by coupling arsenic-responsive genetic circuits with portable, low-cost readouts suitable for field deployment. This review traces the evolution from the early ArsR-based Escherichia coli biosensor to modern whole-cell and cell-free platforms that approach World Health Organization-relevant detection limits for arsenic in water under controlled conditions, emphasizing how signal amplification strategies intersect with shelf life, biosafety, and regulatory simplicity. The operational principles of ars operon-derived modules are examined across detection, processing, and host-engineering layers that collectively tune sensitivity, dynamic range, and robustness. Immobilization formats, microfluidic architectures, and transduction mechanisms─including colorimetric, fluorescent, bioluminescent, and electrochemical outputs─are analyzed for their ability to integrate biological sensing with commodity optics and electronics in portable devices. Building on this engineering landscape, the review highlights how biodesign automation, high-throughput Design-Build-Test-Learn workflows, and emerging AI tools such as supervised learning and Bayesian optimization are accelerating the construction and optimization of arsenic-responsive genetic circuits. Biosafety and regulatory considerations, including biocontainment, standardized stress-testing, and community codesign, are discussed to position arsenic biosensors as candidates for integration into distributed water-quality monitoring networks that combine synthetic biology, low-cost hardware, automation, and AI under robust governance regimes.

Antimony (Sb) is a contaminant of increasing concern; its sources and fate in the environment require particular attention and its isotopes could be useful geochemical tracers. In this study, Sb isotopic composition was investigated along two rivers impacted by mining and smelting activities in the city of Oruro (Bolivia). Antimony concentration and isotope ratio were measured in water, suspended particulate matter and sediments during two contrasted seasons along a gradient of pH (from 1.6 to 6.5) and Sb concentration (from 8057 to 7 µg.L−1). Antimony isotopic composition varied over a range of 1 ‰ considering all sample types (-0.09 ≤ δ123Sb ≤ + 0.93 ‰). The main stream impacted by acid mine drainage showed a progressive increase of δ123Sb in the dissolved phase (+ 0.42 to + 0.70 ‰), concomitant to Fe precipitation and Sb concentration decrease. This suggested that natural Sb attenuation by sorption onto neoformed Fe oxyhydroxysulphates was involved as this process favours light isotopes in the solid (Δ123Sbwater-sediments averaged + 0.3 ‰). Smelting-impacted tributary exhibited lighter dissolved Sb (+ 0.29 ≤ δ123Sb ≤ + 0.36 ‰). Lake Uru-Uru which receives both rivers exhibited a δ123Sb value of + 0.28 ‰ in the wet season and + 0.55 ‰ in the dry season, which might reflect different contributions of the AMD- and smelter-impacted rivers. The study reveals, for the first time, the impact of two distinct anthropogenic sources on antimony (Sb) isotopic composition on a water body and provides new insights into the ability of antimony isotopes to trace sources and processes in contaminated aquatic systems.

Arsenic (As) is one of the most prevalent geogenic trace elements in the groundwater environment that presents a worldwide health concern. In South America, the "Altiplano-Puna" plateau exhibits high As concentrations in water that could be affecting 3 million inhabitants from Argentina, Bolivia, Chile, and Peru. In this As-rich environment with limited water resources, there exists a lack of knowledge regarding the basic geochemistry of As, water quality characterization, and affected population and biodiversity. Between 2020-2022 we performed interdisciplinary research to understand (i) the origin of As, (ii) its geochemistry and mobility, (iii) its distribution in the environment, and (iv) its effects in the local community and unique biodiversity. Our research provides new scientific insights into the biogeochemical cycle of As in the environment and its effect on human health and biodiversity. Our dissemination activities increased the visibility of the As issue for the region that had historically received little attention from the scientific community and local authorities. This project led to additional funding and the creation of a solid research network between the South and North hemispheres, fostering the participation of young researchers, students, and women. An extension of the project was obtained to continue our work during 2023.

El agua subterránea es la principal fuente de consumo en muchos centros urbanos y áreas rurales de Bolivia, tal es el caso del Municipio de San Pedro ubicado en el departamento de Santa Cruz. El presente estudio se realizó con la Received 04 12 2021 Accepted 04 26 2020 Published 04 30 2021 Vol. 38, No.1, pp. 46-55, Ene./Abr.2021 Revista Boliviana de Química 38(1), 46-55, Jan./Apr. 2021 Bolivian Journal of Chemistry DOI: 10.34098/2078-3949.38.1.5 REVISTA BOLIVIANA DE QUÍMICA ISSN 0250-5460 Rev. Bol. Quim. Paper edition ISSN 2078-3949 Rev. boliv. quim. Electronic edition Lizangela Huallpara L. et al. RBQ Vol.38, No.1, pp. 46-55, 2021 Downloadable from: Revista Boliviana de Química. Volumen 38 Nº1. Año 2021 http://www.bolivianchemistryjournal.org, http://www.scribd.com/bolivianjournalofchemistry 47 Received 04 12 2021 38(1); Jan./Apr. 2021 Accepted 04 26 2021 Published 04 30 2021; DOI:10.34098/2078-3949.38.1.5 finalidad de determinar la calidad fisicoquímica del agua subterránea de consumo en 16 comunidades rurales ubicadas dentro del municipio de San Pedro. Los resultados mostraron valores de pH ligeramente alcalinos comprendidos entre 7,8 y 8,6 y la conductividad eléctrica mostró valores en un rango que va de 313,3 a 1189 µS/cm. Las aguas son predominantemente del tipo Na-HCO3 y contienen elevadas concentraciones de fluoruro (F- ) en un rango que va de 2,1 a 6,4 mg/L excediendo el valor máximo recomendado por la Organización Mundial para la Salud (OMS). Cálculos de índice de saturación (IS) muestran que la fase mineral que podría dar origen al elevado contenido de F- en agua es la [F-Apatita].

La presencia de elevadas concentraciones de arsénico encontradas en el agua de consumo de dos sitios geográficamente distantes en Bolivia, ha requerido el diseño, la construcción y la implementación de un sistema de remoción de arsénico para así obtener agua más segura para su consumo. Uno de los sitios se encuentra en una unidad educativa de la zona periurbana de la ciudad de Cochabamba y el otro en una escuela rural en la población de Quillacas en el departamento de Oruro dentro del área del Altiplano boliviano. El sistema consta de dos procesos de remoción de arsénico que funcionan en serie: i) el proceso RAOS que requiere una etapa de aireación y dosificación con sulfato ferroso y citrato de sodio automáticamente controlado con el flujo de agua, 6 fotoreactores provistos de tubos de acrílico de alta transmitancia emplazados en colectores solares tipo Fresnel (con capacidad colectora equivalente a 17,5 soles) y ii) el proceso IHE-ADART que utiliza filtros de arena recubierta con óxido de hierro, IOCS, seguidos de una microfiltración con filtros de polipropileno de 5 y 1 micras dispuestos en serie. El sistema es capaz de remover el arsénico total (particulado y disuelto) hasta concentraciones menores a lo requerido por la guía de la Organización Mundial para la Salud (OMS) y la norma boliviana para agua potable (NB 512) (10 μg/l) en ambas unidades educativas, aun cuando las características hidroquímicas de las aguas tratadas fueron sustancialmente diferentes. Las características del agua de pozo en Cochabamba, favorecen la remoción de arsénico hasta en un 75% por ambos procesos, especialmente el pH, el potencial óxido-reducción y las bajas concentraciones de aniones competidores (cloruros, sulfatos y nitratos) por los sitios de adsorción que están sobre la superficie de los microflóculos de hidróxido férrico o de la capa de óxido férrico que recubre la arena de los filtros IOCS. Por otra parte, las elevadas concentraciones de cloruros, boratos y sulfatos presentes en el agua de pozo que usa la unidad educativa de Quillacas y su alta salinidad no afectan significativamente a la capacidad de adsorción de la arena IOCS, permitiendo elevadas eficiencias de remoción de arsénico (mayores al 90%). En conclusión, el sistema es adecuado, desde el punto de vista técnico para la remoción de arsénico natural presente en aguas subterráneas del valle bajo de Cochabamba y de la zona sur colindante con el lago Poopó en el altiplano boliviano.

Geothermal fluids and volcanic emissions are important sources of arsenic (As), resulting in elevated concentrations of As in ground-, surface-water and soil, which may adversely affect the environment. Arsenic originating from geothermal features and volcanic activities is common in Latin America forming a serious threat to the livelihoods of millions of people. This review attempts to provide a critical overview of the geochemistry of As originating from these sources in Latin America to understand what information exists about and what future research needs to be undertaken. This study evaluated 15 countries in Latin America. In total, 423 sites were characterized with As originating from geothermal sources, mostly related to present volcanic activity (0.001 < As<73 mg/L, mean: 36.5 mg/L) and the transboundary Guarani Aquifer System (0.001 < As<0.114 mg/L, mean: 0.06 mg/L). Many of the geothermal systems and volcanoes discussed in this study are close to densely populated cities, including Bogota, Managua, San José, Guatemala City and Mexico City, where total As concentrations in natural ground- and surface- water exceed the safe drinking water guideline of 0.01 mg/L, recommended by the World Health Organization (WHO). However, the wide geographical occurrence of As in geothermal fluids and volcanic emissions of this region is by far not fully understood, so that development of geographical maps based on geographic information system (GIS) is an urgent necessity to understand the real nature of the problem. The assessment of environmental risks and the potential impacts on human health both inadequate and scarce and hence, these gaps need to be addressed by future research. The present holistic assessment of As originating from geothermal features and volcanic emissions would be a driving force to formulate a plan for establishing a sustainable As mitigation in vulnerable areas of Latin America in the near future. An assessment of the geochemistry, mobility and distribution of As would augment the effectiveness of the plan.