Drinking water & Lead ContaminationKari Knisely1, Austin Atkins2, Jeff Cunningham3

1. Sligh Middle School; 2. Department of Civil & Environmental Engineering, University of South Florida 3. Department of Civil & Environmental Engineering, University of South Florida

For more information about the program visit: http://wareret.net. The Water Awareness Research and Education (WARE) Research Experience for Teachers (RET) is funded by the National Science Foundation under award number 1200682.

Abstract

Objective

Background

Approach

Results

References

Conclusions

While traveling to Madagascar, USF identified a major health risk for the residents of the under developed third world country. The most common source currently used in most villages to retrieve drinking water is being made out of melted lead. The assumption is that the level of lead found in their drinking water pumped from these units contain an unhealthy concentration of lead posing even more serious health risks to the country already struggling to survive many water borne illnesses. USF is seeking to identify which method would be most efficient yet effective to use in the field where electricity is usually not available.

To compare results given by 3 different methods on the 7 different lead concentration levels in drinking water and conclude which method is most effective to be used in the field in Madagascar.

Standard Levels

Method 1 AA

Method 2ASV

Method 3Field Kit- Colorimeterw/ HACH Chemicals

Method 3Field Kit – Colorimeterw/ Leadquick Chemicals

1 mg/L TBA Not in range Not attempted Not attempted150 μg/L TBA Not in range 123 100, 55, 75100 μg/L TBA 95 Not attempted 63, 55, 4350 μg/L TBA 44, 42, 49, 44 30 34, 29, 3210 μg/L TBA 7, 3 Not attempted <3, <3, <35 μg/L TBA 6, 5 Not attempted <3, <3, <32 μg/L TBA 14, 20 Not attempted Not attempted0 μg/L TBA 48, 14 Not attempted <3, <3, <3

7 Concentration Levels made to be tested•1 mg/L•150 μg/L•100 μg/L•50 μg/L•10 μg/L•5 μg/L•1 μg/L

In Madagascar only 47% of the population has access to clean drinking water. In the Eastern part of the island, local artisans dig shallow drinking water wells and install locally manufactured pumps. Lead from old batteries is used for various parts of these pump systems as floats and as solder on the screen in contact with the water. Preliminary sampling of wells in 2010 and analysis for lead using ICP-MS at the University of South Florida (USF) indicated that there were some wells with lead levels above safe limits of 10 ug/L as set by the World Health Organization. Through the Master’s International program in Civil and Environmental Engineering at USF, our team currently has a member on the ground in Madagascar who wishes to test these levels in the field. This research compared the effectiveness of different analytical methods to measure the level of lead contamination in drinking water. The mobile/portable analytical methods include Anodic Stripping Voltammetry (ASV) and Colorimetry with various reagents for color development. Analysis via lab based methods like the Graphite Furnace Atomic Absorption Spectroscopy (GFAAS) were used to compare with the field based kits. The results from this work will be used to identify the most suitable method of analysis for field measurements of lead in drinking water in Madagascar.

3 Methods tested1.Atomic Absorption Spectroscopy (AAS)2.Anodic Stripping Voltammetry (ASV)3.Field Kit - Colorimeter

The AA requires electricity, gas, and is not a mobile method The ASV was extremely self explanatory, accurate, the fastest

method, lightweight and mobile requiring 4 AA batteries The Colorimeter was not consistent in its readings, the chemical

testing process was extremely complicated and time consuming, but was very lightweight and mobile requiring batteries.

The table below demonstrates the readings each method displayed each time it was tested. The closer to the standard the more accurate the test. All photos taken from google images or personal

camera

After researching the different methods displayed in the table, the ASV has proven to be consistent in its results while the Colorimetry methods have been very inconsistent.

The Anodic Stripping Voltammetry (ASV), clearly is the best and most reliable method for accurate readings of lead contaminations less than 100 μg/L. It is unclear at this time, what method is most accurate and recommended for concentration levels over 100 μg/L, but will continue to be researched. The ASV is lightweight, easy to use, and does not require electricity as well as fairly accurate when used to test the lead levels in the standards.

At this time, it will be recommended that USF select the ASV as the measurement method to be used in the field in Madagascar to measure the lead concentration levels in the drinking water supplies.