Environment & Energy

Health impacts of artificial turf: Toxicity studies, challenges, and future directions

Maire Murphy, Genoa R. Warner

Highlights

• Remarkably few studies exist on the health impacts of artificial turf.
• Chemicals identified in artificial turf are known carcinogens, mutagens, and endocrine disruptors.
• Exposure to crumb rubber increases mortality in ecotoxicological studies.
• Exposure to crumb rubber disrupts development in vertebrate animal studies.
• More studies are needed to identify potential health effects in humans.

Abstract

Many communities around the country are undergoing contentious battles over the installation of artificial turf. Opponents are concerned about exposure to hazardous chemicals leaching from the crumb rubber cushioning fill made of recycled tires, the plastic carpet, and other synthetic components. Numerous studies have shown that chemicals identified in artificial turf, including polycyclic aromatic hydrocarbons (PAHs), phthalates, and per- and polyfluoroalkyl substances (PFAS), are known carcinogens, neurotoxicants, mutagens, and endocrine disruptors. However, few studies have looked directly at health outcomes of exposure to these chemicals in the context of artificial turf. Ecotoxicology studies in invertebrates exposed to crumb rubber have identified risks to organisms whose habitats have been contaminated by artificial turf. Chicken eggs injected with crumb rubber leachate also showed impaired development and endocrine disruption. The only human epidemiology studies conducted related to artificial turf have been highly limited in design, focusing on cancer incidence. In addition, government agencies have begun their own risk assessment studies to aid community decisions. Additional studies in in vitro and in vivo translational models, ecotoxicological systems, and human epidemiology are strongly needed to consider exposure from both field use and runoff, components other than crumb rubber, sensitive windows of development, and additional physiological endpoints. Identification of potential health effects from exposures due to spending time at artificial turf fields and adjacent environments that may be contaminated by runoff will aid in risk assessment and community decision making on the use of artificial turf.

Introduction

A key feature of modern society is the drive to optimize and modify our environment with technological advances to improve our quality of life and adapt to changing environmental conditions. However, many such modifications come with increased risk to the natural environment and our own health. Replacing natural grass fields with artificial turf is one example of an “improvement” with unexplored health risks.

Artificial turf is a carpet of synthetic fibers that imitates the appearance of a natural grass field. It is widely used for recreational and professional athletics in the US and Europe. In 2020, the value of the artificial turf market was estimated at $2.7 billion and is experiencing massive growth with the market expected to more than double by 2027, with demand mostly driven by athletics and expanding to markets outside of the US and Europe (Industry Research, 2021). As artificial turf is typically installed in areas that had previously been covered with plant life, this increase in coverage of the Earth's surface with synthetic materials that increase runoff and have been shown to cause heat island effects has important implications for climate change (Shi and Jim, 2022). Proponents of artificial turf prefer the durable polymer surface to optimize limited playing space and time. Grass fields require maintenance, are sensitive to weather conditions, and the health of the grass suffers if fields are overused or improperly cared for (Cheng et al., 2014). Alternatively, opponents of artificial turf are concerned about exposure to hazardous chemicals such as polycyclic aromatic hydrocarbons (PAHs), phthalates, per- and polyfluoroalkyl substances (PFAS), and metals leaching from the synthetic materials, as well as the problematic environmental profile that can exacerbate local climate events (TURI, 2019). In addition, artificial turf cannot be recycled and thus is consigned to a landfill after its useful life of 8–15 years, making it unsuitable for a circular economy.

Despite its increasing market share, the installation of artificial turf in communities around the US is highly controversial, in large part due to the sparce and mixed evidence for its safety. Importantly, the financial incentives of manufacturers to promote adoption of their products make this a prime target for manufactured doubt and scientific obfuscation (Goldberg and Vandenberg, 2021). To date, the majority of scientific studies on artificial turf have focused on chemical components and leachates, identifying numerous carcinogens, neurotoxicants, and endocrine disrupting chemicals, many of which may have non-monotonic dose response curves that indicate there may be no safe level of exposure (Zoeller and Vandenberg, 2015; Hill et al., 2018; Gomes et al., 2021). A few studies have attempted to estimate human exposure from inhalation and ingestion using surrogate biological fluids, environmental monitoring, and calculated estimates, generally finding low biological uptake and estimating low risk (Schilirò et al., 2013; Cheng et al., 2014; Peterson et al., 2018; Donald et al., 2019; Perkins et al., 2019; Pronk et al., 2020). Human epidemiology and laboratory toxicity studies are necessary bridge the gap between the established presence and release of hazardous chemicals by artificial turf and the current exposure estimates.

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