Artificial turf, a synthetic alternative to natural grass, has become a common fixture in sports complexes, playgrounds, and residential landscaping due to its durability and low maintenance. This widespread adoption, however, has been accompanied by ongoing public debate and scientific scrutiny regarding its potential health risks. Concerns center on the materials used in its construction, which may contain various chemical compounds that could be released into the environment. Understanding the true nature of these materials and the scientific evidence on exposure is necessary to objectively assess the potential toxicity of artificial turf systems.
Materials Under Scrutiny
A modern artificial turf system is a composite structure, with different parts contributing distinct materials that are subject to chemical investigation. The turf itself consists of plastic fibers, typically made from polyethylene or polypropylene, which are manufactured to mimic the look and feel of natural grass blades. These fibers are woven into a backing material, often a layer of polyurethane or latex, which provides stability and helps hold the fibers in place.
The primary source of concern, however, comes from the infill material, which is placed between the synthetic grass blades to provide cushioning, stability, and proper drainage. The most commonly discussed infill is crumb rubber, composed of shredded, recycled tires, primarily styrene-butadiene rubber (SBR). This recycled nature means the material can carry a variety of chemicals from its previous life, making it a focus of toxicity discussions. Alternatives to crumb rubber are increasingly used and include materials like silica sand, thermoplastic elastomers (TPE), ethylene propylene diene monomer (EPDM), and organic infills such as coconut fibers or cork.
Contaminants and Chemical Exposure
The recycled nature of crumb rubber infill means it contains a complex mixture of chemical compounds, many of which have known toxic properties. Among the most concerning are Polycyclic Aromatic Hydrocarbons (PAHs), which are a group of chemicals that are known carcinogens and are present in high concentrations in recycled rubber. Studies often focus on the eight PAHs identified by the European Chemicals Agency due to their potential to cause cancer.
Heavy metals are also frequently detected in the infill and sometimes in the turf fibers, including zinc, cadmium, and lead. Zinc is often found at notably high concentrations because it is a key component in the vulcanization process used to manufacture tires. Lead is a neurotoxin, and while it is more common in older turf fields where it was used as a pigment, its presence is a significant health concern, particularly for children.
Volatile Organic Compounds (VOCs) like benzene and toluene can also be released from the materials, especially under the high temperatures artificial turf can reach. These compounds transition easily into a gas and can be inhaled, raising concerns about respiratory exposure. An emerging concern is the presence of Per- and polyfluoroalkyl substances (PFAS), known as “forever chemicals,” which have been identified in the synthetic fibers and backing material of some turf products.
How Exposure Occurs and Current Research
Chemicals present in artificial turf can enter the human body through several distinct exposure pathways during use. Inhalation occurs when users breathe in the volatile organic compounds that off-gas from the turf, or when they inhale fine particles of infill dust that become suspended in the air. Incidental ingestion is another pathway, especially for children, where infill particles are transferred from hands or objects to the mouth. Dermal contact is also a pathway, particularly when skin is broken by abrasions, commonly called “turf burns,” which allows chemicals to potentially enter the bloodstream. This is further complicated by the fact that heat and sweat can increase the rate at which some chemicals are released from the material and absorbed through the skin. The movement of infill particles that cling to clothing and shoes also tracks the material into homes and vehicles, extending the exposure window.
Major regulatory bodies, including the Environmental Protection Agency (EPA) and the Centers for Disease Control and Prevention (CDC), have conducted research to assess the actual risk from these chemicals. Many comprehensive human health risk assessments suggest that the risks of cancer and non-cancer health effects from exposure to crumb rubber infill are low or negligible under typical use conditions. Studies have found that chemical exposure levels are often comparable to those encountered on natural grass fields. However, these assessments often acknowledge limitations, such as the difficulty in accounting for all variables, including the age and wear of the turf, the specific type of chemicals present, and prolonged exposure scenarios. The CDC and CPSC have also highlighted the need for precautions, especially concerning lead exposure, noting that children are a particularly sensitive population due to their developing bodies and higher rates of hand-to-mouth activity. The overall scientific consensus is that while chemicals are present, the level of exposure does not consistently translate into a substantial health risk for the average user.
Safety Measures and Risk Reduction
Individuals and facility managers can take several proactive steps to minimize potential chemical exposure and other risks associated with artificial turf. Maintaining good hygiene after using the turf is a simple yet highly effective measure. Users should shower and wash their hands and bodies thoroughly with soap and warm water immediately after play to remove any residual infill particles or dust. It is also advisable to change clothes and shoes promptly after leaving the field, washing the soiled items separately to avoid tracking any particles into living spaces. To reduce incidental ingestion, users should avoid eating or drinking directly on the turf surface and ensure that beverage containers are covered and kept off the field. For new installations, facility managers can significantly reduce potential chemical hazards by selecting alternative infills, such as TPE, EPDM, or organic materials, which typically contain fewer regulated contaminants than crumb rubber. Regular maintenance is important, including brushing the turf to keep fibers upright and inspecting the field for signs of wear. Monitoring the turf’s surface temperature is another practical measure, as higher heat increases the off-gassing of VOCs; lightly spraying the field with water can help keep the temperature down.