New schools are being built from old plastic; new chipboard from the waste from cocoa crops.
Now, two graduates from Denver University want to do something about the 80 million used tyres residing nearby.
They have reversed the thermoplastic process by which rubber is made into synthetic plastic.
During the so-called devulcanization process, toxins and sulphur components are broken down and separated.
The remaining rubber is an environmentally-friendly construction material which can be used as either an insulating or a breathable layer.
With their heat-insulating properties, using the tiles for exterior walls could significantly reduce building costs.
The product could also serve as inspiration for other recycling innovations.
Elsewhere, work is underway to re-use captured pollution from tyre wear.
