Waste Tyre Environmental Impacts and Life Cycle Assessment Review for Reuse, Material Recovery, and Energy Recovery Strategies

The utilization of post-consumer tyres in reuse, energy, and material recovery initiatives is perceived as environmentally sound methodologies to reduce waste, provide an affordable energy source, and to provide supplementary materials such as tyre rubber crumb for use in civil and construction applications. However, over the years, scientists have raised concerns over the long-term impact of end-of-life tyres on the environment and human health. This paper identifies the potential environmental and health impacts (including terrestrial, aquatic, and airborne) of reuse, material and energy-recovery waste tyre management options and reviews their life cycle assessment impacts. Despite the potentially hazardous chemicals employed in the manufacturing of tyres, published data reflects inconclusive evidence regarding the risks posed by applying waste tyres or waste tyre-derived rubbers to humans and the environment. The lack of definitive evidence is the motivation for this research, which also aims to contribute to the identification and assessment of ecologically acceptable tyre disposal strategies. To address this issue, many developed and developing countries have explored the use of life cycle assessment (LCA) tools to quantify the environmental loads associated with the life cycle stages of waste tyres, primarily manufacturing, transportation, application, and to identify the best disposal strategy (reuse, material, and energy recovery) that will yield the least environmental impacts.