Are synthetic-turf systems contributing to the problem?
By Thomas P. Shay
Photo Credit: Woodard & Curran
Most third-generation, synthetic-turf fields installed worldwide use some form of rubber as a significant component of infill. Typically, styrene butadiene rubber (SBR) is used as a cost-effective synthetic, often referred to as crumb rubber. Other virgin rubber and plastic alternatives include ethylene propylene diene monomer (EPDM) or thermoplastic elastomers (TPE).
SBR is often sourced from worn-out automobile-tire waste and diverted to synthetic-turf fields for infill. The substance is a low-cost material that has been historically suitable for field surfacing with particles approximately 1 to 2 millimeters in size. However, the particulate nature of SBR means it is easily carried away from synthetic fields by athletes on shoes, clothing, equipment, hair, or skin, and this requires replenishment. Some of the crumb rubber can be found in perimeter areas surrounding synthetic-turf fields, especially when snow removal is conducted on the turf as part of maintenance.
Determining The Threat To Environmental And Human Health While researchers are still determining the health effects of SBR applications, crumb rubber has the potential to release a variety of chemicals and particles into the environment, according to studies conducted by the California Office of Environmental Health Hazard Assessment (OEHHA) in 2007, 2010, and 2016. In 2016, the U.S. Environmental Protection Agency (EPA) stated âlimited studies have not shown an elevated health risk from playing on fields with tire crumb, but the existing studies have not comprehensively evaluated the concerns about health risks from exposure to tire crumb rubber, and important data gaps exist.â A multi- agency research effort was launched to investigate the impacts of upwards of 13,000 synthetic-turf fields in the United States. Further, SBR has the potential to impact the environment by contributing to microplastics that contaminate surface water. It is notable that Environmental Science and Technology identified tire-wear particles (TWPs) as an âunder-appreciated contaminant source in urban watersheds, and should be prioritized for fate and toxicity assessment.â While TWPs are not directly related to SBR contaminants, parallels may be drawn to consider the bigger picture regarding the spread and subsequent breakdown of SBR particulates over time in the environment, and how that contributes to the broader issue of microplastics contamination.