In Rio de Janeiro's Guanabara Bay, discarded salon hair is being transformed into an oil-absorbing barrier that protects mangroves from oil spills

• When scientists have a will, there is always a way.
• In a shocking yet successful project, leftover hair from haircuts that is not suitable for wigs and would have gone to waste is now being used to prevent oil and other pollutants from getting into the water and the trees.
• In Rio de Janeiro's Guanabara Bay, a barrier made from human hair discarded by beauty salons is being used to prevent pollution.