Artificial turf is a synthetic substitute for natural grass used widely across sports fields, playgrounds, and residential landscaping. It consists of plastic fibers, a backing layer, and an infill material that keeps the blades upright and provides cushioning. The popularity of these surfaces is driven by their durability and low maintenance needs. Public concern regarding the potential toxicity of artificial turf stems directly from the materials used in both older and modern installations. This article provides an overview of the chemical components and exposure pathways associated with artificial turf systems.
Hazardous Components in Artificial Turf Systems
The main chemical concern in many artificial turf installations is the crumb rubber infill, often made from shredded, recycled vehicle tires. This material contains a complex mixture of chemicals used in tire manufacturing, including heavy metals like zinc and trace amounts of lead. Crumb rubber can also release volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs), which are byproducts of petroleum and rubber processing.
The synthetic fibers and their backing layer also contribute to the chemical profile. These plastic components, typically made from polyethylene or polypropylene, can degrade over time, shedding microplastic particles into the environment. Lead was historically used as a pigment and stabilizer in the fibers, especially in turf installed before the mid-2000s. This makes older fields a greater risk for lead exposure.
A growing concern involves the potential presence of Per- and Polyfluoroalkyl Substances (PFAS), a class of persistent chemicals. These “forever chemicals” are sometimes used during manufacturing to help plastic fibers release from molds or to enhance durability. The presence of PFAS adds to the complexity of potential chemical exposure, given their known links to various health issues.
Routes of Exposure and Associated Health Concerns
Exposure to chemicals in artificial turf occurs through several distinct pathways. Inhalation is a primary route of concern, as the breakdown of crumb rubber and synthetic fibers creates fine particulate dust that becomes airborne. This dust carries heavy metals and PAHs, which can cause respiratory irritation and potentially lead to long-term health effects when breathed in.
Volatile organic compounds (VOCs) are released into the air through off-gassing, especially when the turf is new or exposed to high temperatures. Exposure to these airborne chemicals, particularly in poorly ventilated indoor facilities, is linked to symptoms like headaches and eye irritation. Studies have detected various VOCs, including benzene and toluene, in the air above turf surfaces.
Ingestion and dermal contact are primary concerns, particularly for children who engage in hand-to-mouth behavior or play directly on the surface. Small particles of crumb rubber can be inadvertently swallowed, leading to exposure to heavy metals like zinc and trace amounts of lead. Dermal contact, especially when the skin is compromised by a friction burn (turf burn), can increase the absorption of leaching chemicals.
Heat Amplification
Heat amplification on artificial turf represents a distinct physical and chemical health hazard. Unlike natural grass, synthetic turf absorbs solar radiation and can reach surface temperatures significantly higher than the ambient air temperature, sometimes exceeding 150°F. This extreme heat poses an immediate risk of thermal burns and heat-related illnesses like dehydration and heatstroke.
Elevated temperatures also increase the rate at which VOCs off-gas from the materials and accelerate the chemical breakdown of turf components. This process enhances the release of potentially harmful substances, effectively linking the physical hazard of heat to the chemical exposure risks.
Regulatory Standards and User Safety Precautions
The regulatory landscape for artificial turf materials is often fragmented, with oversight varying significantly by jurisdiction and often focusing on specific legacy contaminants. Many existing testing standards address heavy metals, such as lead in the turf fibers, but may not fully encompass emerging concerns like PFAS or the full spectrum of VOCs. Federal research on crumb rubber has acknowledged the presence of various chemicals but suggests that human exposure is limited.
In the absence of comprehensive and uniform national standards, consumers and users should adopt specific safety precautions to minimize potential risks. Always wash hands and exposed skin immediately after contact with the turf to remove any adherent dust or crumb rubber particles before eating. Avoid using the turf during the hottest parts of the day, as high surface temperatures pose a risk of thermal injury and increase chemical off-gassing.
If possible, inquire about the type of infill material used. Alternatives to crumb rubber, such as coated sand, coconut coir, or cork, are available and may reduce chemical exposure concerns. For turf used in enclosed spaces, ensure adequate ventilation to prevent the buildup of off-gassed VOCs. If a friction burn occurs, clean and cover the wound promptly to reduce chemical absorption and infection.