A simple test to detect fluoride in drinking water quickly could prevent skeletal fluorosis, a crippling bone disease, according to a team of researchers from the Centre for Sustainable Chemical Technologies and the Water Innovation and Research Centre (WIRC) at the University of Bath, UK.
The study is published in the journal Chemical Communications.
Fluoride is needed for healthy teeth, but too much of it can weaken bones and cause deformities of the joints and spines, which can be particularly dangerous for children whose bone structures are still developing. Exposure to elevated fluoride has also been linked to reduced IQ in many studies, according to the Fluoride Action Network.
Elevated levels of fluoride are found in drinking water sources in parts of East Africa, India, China and North America. This is due to water dissolving fluoride when it passes over certain minerals.
While developed countries usually have systems in place to monitor and control fluoride levels, that is not the case in parts of the world where there is a lack of piped water or fluoride treatments, such as India and Tanzania, and people are forced to rely on untreated water from wells that can contain higher than recommended levels of fluoride.
Levels of fluoride in groundwater fluctuate with the weather, particularly when there’s heavy rain.
The Test
Led by Dr. Simon Lewis, the team devised a simple color-changing test that detects high levels of fluoride quickly. When levels get too high, the color changes from purple to blue in a matter of minutes.
“Most water quality monitoring systems need a lab and power supply and a trained operator to work them,” Lewis said in a statement. “What we’ve developed is a molecule that simply changes colour in a few minutes which can tell you whether the level of fluoride is too high.”
The fluoride tests used in the study are a proof of concept, but the team’s goal is to create a test strip that is cheap and can be used by anyone.
“This technology is in the very early stages, but we’d like to develop this technology into test strips, similar to litmus paper, that allow people without any scientific training to perform a test that is low cost, rapid and robust,” said Lewis in a statement.
Developments
The team has partnered with the Nasio Trust, a charity organization, to develop the technology for field use in the Oldonyosambu area of Arusha Tanzania in East Africa, where fluoride levels can rise to more than 60 times higher than the U.S. recommended levels.
The charity “has already sent us some water samples that will help us to improve this technology,” said Carlos López-Alled, the integrated Ph.D. candidate at the university’s Centre for Sustainable Chemical Technologies behind the development of the fluoride sensors.
Field testing will start once the sensor has been immobilized on paper, he said.
The team is in the process of adding a new postdoctoral researcher who will work specifically on the immobilization of the sensor on paper strips, he added. He expects the strips to be ready by 2019.
Other Applications
López-Alled is currently working on a “mercury sensor that is showing to be very promising,” he said.
A university in Colombia — Universdad de los Andes — is already interested in the mercury sensor, and the partnership will be formalized in the next few weeks, he added.
The team is also looking to adapt the technology to detect lead and cadmium in water.
López-Alled believes that the technology would be very useful in health care as well.
“I think that colorimetric tests will expand from environmental science to health care,” he said. “The rapid and easy detection of diseases could save much money and time to the health services and ultimately save more lives. We already have colorimetric pregnancy test; we will see diseases being diagnosed in the same way very soon.”
The team is looking for more partners to further develop the technology.
