The SDAB has commissioned a lifecycle analysis for the three areas where cut-up tyres are used. They are artificial grass pitches, riding tracks and covering landfill. The research was performed by IVL, the Swedish Environmental Research Institute.
Artificial grass mats
Tests on artificial grass mats compared the use of used tyres to new rubber. Tyre granules in artificial grass give significantly lower emissions of greenhouse gases than the newly-produced rubber used for comparison. The conclusion was the same for other environmental categories, such as acidification and eutrophication. The reason for such results is the use of a recycled material instead of manufacturing something new from virgin raw materials. The limit value for metals and other substances harmful to the environment leached out is far from reached for all the materials studied.
Cut-up tyres are used as the spring layer to provide a more comfortable surface for the horse. The results show a certain impact on the environment, but there are no realistic alternatives at this time.
When a landfill site is to be covered over, it can either be done with crushed stone or cut-up tyres. When all parts of the process are included, both methods are found to give the same greenhouse gas emissions. Leach tests performed in other contexts show that very small amounts are leached, and that there are no environmental differences between both materials.
A good environmental alternative
"After studying the results, I cannot see that tyre granules perform any worse than any other alternative material from an environmental point of view," says Tomas Rydberg Project Manager at IVL. Most metals were not found in measurable amounts, making the metal aspect irrelevant. The higher amount of PAH traces in artificial grass compared to new materials will in fact drop, as PAH oils are no longer used for the manufacture of new tyres.