A global reconnaissance of particulates and metals/metalloids in untreated drinking water sources

Metal and metalloid contamination in drinking water sources is a global concern, particularly in developing countries. This study used hollow membrane water filters and metal-capturing polyurethane foams to sample 71 drinking water sources in 22 different countries. Field sampling was performed with sampling kits prepared in the lab at Hope College in Holland, MI, USA. Filters and foams were sent back to the lab after sampling, and subsequent analysis of flushates and rinsates allowed the estimation of suspended solids and metal and other analayte concentrations in source waters. Estimated particulate concentrations were 0-92 mg/L, and consisted of quartz, feldspar, and clay, with some samples containing metal oxides or sulfide phases. As and Cu were the only analytes which occurred above the World Health Organization (WHO) guidelines of 10 mu g/L and 2000 mu g/L, respectively, with As exceeding the guideline in 45% of the sources and Cu in 3%. Except for one value of similar to 285 mu g/L, As concentrations were 45-200 mu g/L (river), 65-179 mu g/L (well), and 112-178 mu g/L (tap). Other metals (Ce, Fe, Mg, Mn, Zn) with no WHO guideline were also detected, with Mn the most common. This study demonstrated that filters and foams can be used for reconnaissance characterization of untreated drinking water. However, estimated metal and other analyte concentrations could only be reported as minimum values due to potential incomplete retrieval of foam-bound analytes. A qualitative reporting methodology was used to report analytes as present if the concentration was below the WHO guideline, and present-recommend retesting if the concentration was quantifiable and above the WHO guideline.

Automated summary

Metal and metalloid contamination in drinking water sources is a global concern, with arsenic and copper exceeding WHO guidelines in certain sources. The study demonstrated the use of hollow membrane water filters and metal-capturing polyurethane foams for sampling and analysis, with some metal concentrations in source waters above recommended levels. Additionally, other metals were detected, with manganese being the most common.