Artificial Turf Fields Act as Recurring Point Sources of Metals and Emerging Tire-Derived Contaminants in Stormwater

Abstract

Artificial turf fields are widely used globally. Each field contains an estimated 125 tonnes of infill material, which is often composed of ground post-consumer vehicle tires. Tires contain chemicals that are deleterious to human health and aquatic ecosystems, which may be mobilized from artificial turf fields. We conducted laboratory leaching experiments and analyzed stormwater from multiple artificial turf fields to quantify contaminant release. We found that crumb rubber infill released several toxicants including N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine-quinone (6PPD-Q), zinc, and copper, at higher levels than alternative infill materials. 6PPD-Q and 6PPD concentrations in infill leachates did not decrease with infill age. Non-targeted analysis identified fourteen compounds associated with crumb rubber infill material, including the putative identification of the bioaccumulative toxicant leucomalachite green. The maximum 6PPD-Q concentration in stormwater draining from an artificial turf field (130.2 ng L^-1) was over three times higher than the LC₅₀ for juvenile coho salmon (Oncorhynchus kisutch), which could increase concentrations to concerning levels in receiving water bodies. Zinc and copper concentrations peaked at 30.3 and 726.4 μg L^-1, respectively. These concentrations are toxicologically relevant but lower than those typically observed in urban road runoff. Our results indicate that a typical crumb rubber-infilled field likely releases <1% of the total 6PPD in the infill material to stormwater each year, indicating persistent release beyond the field lifespan. Thus, artificial turf fields can act as recurring point sources of contaminants at ecologically significant levels.