A review of potentially harmful chemicals in crumb rubber used in synthetic football pitches

• Published in: Journal of hazardous materials 2021-05, Vol.409, p.124998, Article 124998
• Main Authors: Gomes, Filipa O., Rocha, M. Rosário, Alves, Arminda, Ratola, Nuno
• Format: Article
• Language: English
• Subjects: Artificial turf; Crumb rubber; End-of-life tires; Environment and public health; Hazardous chemicals monitoring
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2020.124998

Recycling end-of-life tires (ELTs) reduces waste and provides a low-cost source of energy and materials such as crumb rubber, used as infill in artificial turf football pitches. However, some concerns were raised and remain about its safety. The potentially toxic human exposure to chemicals such as polycyclic aromatic hydrocarbons (PAHs), metals and others (volatile organic compounds (VOCs), plasticizers, antioxidants and additives) existing in ELTs (and in the resulting crumb rubber) is being studied, with no definitive conclusions. The literature existing so far suggests the possibility of their release from synthetic turf infill into the environment as water leachates and to the air surrounding the pitches, but there is the need of further research, also to assess the contribution of other materials present in synthetic turf. The database available comprised crumb rubber infill studies from pitches in 6 countries (USA, Norway, Netherlands, Portugal, Italy, Spain) and revealed a myriad of hazardous chemicals, with benzo[a]pyrene (n.d.–4.31 ± 3.95 mg/kg) and zinc (n.d.–14150 ± 1344 mg/kg) often exceeding the established limits. A dependence on indoor/outdoor conditions and the age of the source material was evaluated, often showing significative differences. From this standpoint, this review is intended to add knowledge about the presence of contaminants in this recycled material, aiming to ensure the safety of end-users and the environment. [Display omitted] •Crumb rubber (CR) from recycling end-of-life tires is used as synthetic turf infill.•Potentially hazardous chemicals were reviewed in CR, water leachates and nearby air.•8-carcinogenic PAH levels from 1.91 to 24.67 ± 18.31 mg/kg surpass the legislated limit.•Zn was the prevalent metal, up to 15,494 mg/kg in CR and 34,170 μg/L in water leachates.•Other contaminants linked to tire making like VOCs, plasticizers or PCBs were found.