A group of researchers created an affordable, portable water-testing device known as the E-Tongue to enable people to identify lead pollution in their own homes. Four towns in Massachusetts participated in a citizen science initiative that tested the device, which was detailed in ACS Omega.
The E-Tongue is an easy-to-use device that tests for potential lead contamination in drinking water at home. Image Credit: Adapted from ACS Omega
Lead contamination in municipal water sources poses an ongoing concern to human health. Ingesting even trace lead levels can impair the human brain and nervous system, particularly in youngsters.
I was driven by the reality that families could be unknowingly exposed to lead. With the E-Tongue, we are putting knowledge and power directly into people’s hands so they can protect their health and advocate for safer water in their communities.
Pradeep Kurup, Principal Investigator, University of Massachusetts Lowell
Traditional water tests are expensive and time-consuming, necessitating specialized scientific equipment and lengthy processing times. Furthermore, while water treatment plants are quite effective at eliminating toxins, old lead pipes and plumbing fixtures in residences can still be a source of lead pollution.
To address this issue, Kurup and his team of researchers created the E-Tongue, a portable, user-friendly gadget for evaluating water samples.
The E-Tongue works by applying voltage to a water sample, which causes any lead ions present to adhere to the sensor's gold electrode. The voltage is then reversed, causing the lead to come off the sensor and generate an electrical current. The intensity of this current represents the amount of lead in the water sample.
If lead is discovered, a smartphone app connected to the gadget notifies the user with a color-coded reading and a concentration value indicating the level of contamination. A green screen shows that the lead concentration exceeds the US Environmental Protection Agency’s (EPA) regulation limits. A red screen indicates that the lead concentration is above the permissible limit.
The researchers conducted usability and performance tests on the E-Tongue with 317 residents from four nearby towns. The inhabitants mixed a tap water sample in a glass vial with a pre-made buffer solution.
Then, using the smartphone app, they performed three steps: clicking “start” after inserting the sensor into the vial, clicking “run” to start the test, and clicking “end” to preserve and share the test results with the researchers and local municipalities.
If lead levels exceed the EPA's maximum allowable level of 10 parts per billion, the researchers confirmed the results with a recognized laboratory using traditional testing methods to assure E-Tongue’s accuracy.
The researchers found that:
- The levels of lead contamination in tap water tests varied among the four Massachusetts towns
- Ten of the 634 samples gathered by the residents surpassed the EPA’s maximum allowed amount of lead, with several more approaching this value.
- The E-Tongue measurements were as precise as traditional laboratory tests
This study shows that the E-Tongue is a quick and reliable technology for detecting lead in drinking water at home. The researchers anticipate that this technique will soon become a viable option for detecting and reducing heavy metal pollution in municipal water supplies, empowering communities to protect themselves.
The National Science Foundation provided funding for the study.
Journal Reference:
Bozkurt, Y. C., et al. (2025) Community-Wide Monitoring of Lead in Drinking Water Distribution Systems Using Hand-Held Voltammetric Sensors and Geographic Information Systems. ACS Omega. doi.org/10.1021/acsomega.5c01580.