A simple colour-changing test to rapidly detect fluoride in drinking water may help prevent skeletal fluorosis, a crippling bone disease, in developing countries such as India, scientists said today.
While low amounts of fluoride are beneficial for healthy teeth, high levels of fluoride can weaken bones, leading to skeletal fluorosis, said researchers at the University of Bath in the UK.
This disease causes crippling deformities of the spine and joints, especially in children whose skeletons are still forming, they said.
When water passes over certain minerals, it can dissolve fluoride, which results in elevated levels of fluoride in drinking water sources in parts of India, East Africa, China and North America.
Levels of fluoride in drinking water are routinely monitored and controlled at treatment works in developed countries.
However, in areas where there is no piped water system or treatment works, people rely on drawing untreated water from wells, which can often be contaminated with higher than recommended levels of fluoride.
The amounts of fluoride in the groundwater can vary due to weather events, with levels fluctuating hugely when there is a lot of rain.
A research team led by Simon Lewis from the University of Bath has developed a simple colour-changing test that detects high levels of fluoride quickly and selectively.
While the test is at the proof of concept stage, the team aims to develop it into a disposable test strip that is low cost and easy to use by anyone.
"Whilst a small amount of fluoride is good for your teeth and prevents tooth decay, high levels are toxic and can cause crippling deformities that are irreversible," Lewis said.
"Most water quality monitoring systems need a lab and power supply and a trained operator to work them. What we have developed is a molecule that simply changes colour in a few minutes which can tell you whether the level of fluoride is too high," said Lewis.
"We would 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.
"We anticipate that in the future it could make a real difference to people's lives," said Lewis.