Laboratory Cross-checking of Field Arsenic Measurement: Its Importance in Contaminated and Uncontaminated Drinking Water Sources Screening in Bangladesh

摘要

Arsenic is a deadly poison found in some tube-wells of Bangladesh. Watsan Partnership Project (WPP) launched an Arsenic Program in 484 villages of Rajshahi and Chapai Nawabganj districts to screen all the potable sources of water. Arsenic Survey Team (AST) under 12 NGOs did the field arsenic screening with E-Merck Field Kit. To check the accuracy level of field arsenic measurement, the Laboratory and Quality Control Team collected two water samples from each village and analyzed in WPP Laboratory with silver diethyldithiocarbamate method using sodium borohydride as reducing agent. From laboratory cross-checking, it was found 5.26% error in field arsenic measurement in 1st Phase (Model Village), 12.87% in 2nd Phase and 3.3% in 3rd Phase. For higher error in 2nd Phase, re-testing was conducted in ACD, BIKASH and MSP NGOs areas, and after re-testing, 30% error in field measurement was found in ACD, 9.16% in BIKASH and 15.55% in MSP area.