Evaluation of two new arsenic field test kits capable of detecting arsenic water concentrations close to 10 μg/L

Millions of people worldwide are exposed to arsenic-contaminated drinking water. Arsenic field test kits may offer a cost-effective approach for measuring these exposures in the field, although the accuracy of some kits used in the past has been poor. In this study, arsenic concentrations were measured in 136 water sources in western Nevada using two relatively new arsenic test kits and compared to laboratory measurements using atomic fluorescence spectroscopy (AFS). Spearman's rank correlation coefficients comparing the Quick Arsenic and Hach EZ kits to laboratory measurements were 0.96 (p < 0.001) and 0.95 (p < 0.001), respectively. When analyzed in seven exposure categories (0-9, 10-19, 20-49, 50-99, 100-199, 200-499, and >= 500 mu g/L), test kit and AFS measurements were in the same category in 71% (Quick Arsenic) and 62% ( Hach EZ) of samples, and within one category of each other in 99% ( Quick Arsenic) and 97% ( Hach EZ) of samples. Both kits identified all water samples with high arsenic concentrations (> 15 mu g/L) as being above the United States Environmental Protection Agency's drinking water standard and the World Health Organization's guideline value for arsenic of 10 mu g/L. These results suggest that these easily portable kits can be used to identify water sources with high arsenic concentrations and may provide an important tool for arsenic surveillance and remediation programs.