See fascinating short video at the start of this short article
High fluoride levels in water cause teeth discolouration and in extreme cases, bone decay.
In many countries, fluoride is added to water and toothpaste to make teeth stronger. But, when there is too much fluoride, it can be toxic. In Ethiopia, at least 16 million people are affected by this.
Al Jazeera’s Leah Harding visited the small town of Mojo, which is trying to fix its fluoride problem in a creative way.