Measurement of arsenic concentration in drinking water of a polluted area using a field and SDDC methods accompanied by assessment of precision and accuracy of each method

Consumption of water contaminated with arsenic can cause different adverse health effects in humans. Therefore measurement of arsenic concentration in drinking water resources is necessary before implementation of any water supply projects and during operation and also for determination of any treatment processes efficiency.In this research we aimed to determine arsenic content of drinking water resources of some villages in Bijar city of Kurdistan province.  

For this purpose accuracy and precision of two field (Ez arsenic test kit) and laboratory silver diethyldithiocarbamate spectrophotometric method (SDDC) for measurement of arsenic in water was studied. Accuracy and precision of both methods was determined through analysis of synthetic distilled water containing specific concentration of arsenic. Then 44 villages was monitored and samples of polluted water was analyzed using SDDC.  

The results showed that both studied (field and laboratory) methods have high precision and accuracy for measurement of arsenic in drinking water. In the case of kit it is necessary to use 9.6 ml as sample volume. The field monitoring of 44 villages of Bijar showed that drinking water of 5 villages has high level of arsenic considering national drinking water standard for arsenic (50µg/L). The highest level of arsenic was observed in Gavandak equal to 422.5µg/L (8 times of national standard and 42 times of WHO guideline).  

Considering the widespread location of water sources in our country, it is recommended that Ez arsenic test kit could be used in the wide range of field monitoring activities. For accurate evaluations, SDDC method is preferred at reference laboratories considering advantages of mthod e.g speciation definition and independency to advanced instruments.