Arsenic contamination study of drinking water in Nepal

Abstract

A study of arsenic contamination of drinking water in Nepal was conducted. Samples were collected in Nepal in January 2000 from tube wells, hand dug wells, natural springs, municipal systems and surface water bodies. Samples were analyzed in Nepal using EM Quant@ test strips and Affiniti Concentration kits. Samples were also preserved and brought back to the U.S. for analysis using Graphite Furnace Atomic Absorption Spectrometry. Combined results from these tests indicate that no arsenic contamination was found above the World Health Organization (WHO) maximum contaminant level of 10ppb in the Kathmandu Valley. However, 18% of samples taken from the Terai region of Nepal were above the WHO limit. Detectable levels of arsenic were found in tube wells ranging from approximately 30 to 300 feet deep. Forty-eight percent of samples taken from wells aged 9 to 12 years had detectable levels of arsenic. This study concludes that, although not as extensive as in neighboring West Bengal, India and Bangladesh, arsenic contamination does exist in the Terai region of Nepal. A comparison of analytical methods indicates that field kits provide a general indication of high levels of arsenic, but should be used in conjunction with more accurate methods if detailed results are required. Further testing is recommended in the Terai region of Nepal. A detailed study of the geology of the Terai region and potential anthropogenic sources is recommended to further characterize the area.