News > "Arsenic field screening in Nicaragua"
Arsenic field screening in Nicaragua October 27, 2010 08:06
Nuevas Esperanzas (‘New Hope’), a local development agency serving the needs of communities in Nicaragua is carrying out a crucial field screening programme for arsenic in the department of León using the Wagtech Digital Arsenic Test Kit.
The study has focused on the volcanic region of Telica where high levels of arsenic were first found in two wells in 2009. Nuevas Esperanzas has since embarked on a complete field screening programme for the local Government, in order to accurately map levels of arsenic in the region.
Focused principally on long-term development programmes in León, Nuevas Esperanzas is a Christian organisation run by highly professional and dedicated individuals. The Director of the company, hydrogeologist Andrew Longley, has been in regular contact with Wagtech and has been responsible for the development of this well organised and crucial environmental survey. Andrew is an experienced programme manager and has a PhD in Geology, a Masters degree in Groundwater Engineering and further training in technical and managerial aspects of relief and development work.
Arsenic is an important drinking-water contaminant. Drinking water rich in arsenic over a long period leads to arsenic poisoning, referred to as arsenicosis. This results in various health effects including skin problems (such as colour changes on the skin, and hard patches on the palms and soles of the feet), skin cancer, cancers of the bladder, kidney and lung, diseases of the blood vessels of the legs and feet, and possibly also diabetes, high blood pressure and reproductive disorders.
Arsenic is a ubiquitous element found in the atmosphere, soils, rocks, natural waters and organisms the world over. High arsenic concentration levels in water are principally restricted to groundwater, with some exceptions. It is mobilised in the environment through a combination of natural processes such as weathering reactions, biological activity and volcanic emissions as well as through anthropogenic activities. Most environmental arsenic problems are the result of mobilisation under natural conditions, but man has had an important impact through mining activity, combustion of fossil fuels, the use of arsenical pesticides, herbicides and crop desiccants.
This present study involves the mapping of all the wells in the region, registering the depth to water, the type of pump and the use of the water. The water is then tested for pH, total dissolved solids, and arsenic. Initially used for widespread screening programs by aid agencies in Bangladesh, the Arsenator provides an in-situ method for quickly and accurately quantifying the levels of arsenic in a sample in the critical range of 2-100ppb (µg/l). The simplicity of the method and portability of the kit makes it ideal for use in such situations, negating the requirement for lengthy laboratory analyses. The sample is collected in a flask and a unique tri-filter bung is attached which includes an impregnated filter paper. Reagents added to the solution produce a reducing condition which converts all the inorganic arsenic in the sample to arsine gas. This gas reacts with the filter paper, discolouring the paper a shade of brown. The extent of this colour is directly proportional to the concentration of arsenic in the sample, which is then measured digitally by the Arsenator device.
Nuevas Esperanzas has begun to map the results of the study and will be publishing more information in due course. For a report of their work and more information, please visit www.nuevasesperanzas.org.
The full story is available online here.
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