Schools, universities, and municipalities often face the need to make a choice between natural grass athletic fields and artificial turf.
These choices can involve substantial monetary investments. Reasons some cite for choosing artificial turf can include an expectation of more playable hours; expectations of reduced water use and/or reduced maintenance needs; and the perception that it is the “premium” option.
However, these considerations are multi-faceted and involve trade-offs. For example, communities often face maintenance problems with an existing grass field, but do not fully explore the improvements in field quality and playable hours that can be obtained through better maintenance of grass fields. In addition, communities do not always take account of future needs related to maintenance, repair and eventual disposal of artificial turf.
The Toxics Use Reduction Institute (TURI) at the University of Massachusetts Lowell has worked with schools and other institutions to research best practices for creating and maintaining athletic fields that are cost-effective and preferable for human health and the environment. Sources of support for this work include the Pittsburgh-based Heinz Endowments.
Artificial turf lasts for eight to 10 years, after which it is typically disposed of in a landfill; while some components of the turf system may be reusable one or more times, others may have to be disposed of in a landfill or through incineration when the field is due for replacement, contributing to solid waste pollution. Environmental concerns also include loss of wildlife habitat when green space is replaced with synthetic turf, and migration of rubber and plastic particles into the environment, contributing to microplastic pollution.
From a climate change perspective, going with synthetic turf means loss of the potential to capture carbon in a healthy soil ecosystem. The loss of green space also contributes to the urban heat island effect.
Artificial turf does not eliminate the need for water; in some cases, it is irrigated with water in order to temporarily bring down high surface temperatures. Maintenance can include treatment with antimicrobials, as well as periodic addition of infill to replace the infill that migrates off the field into the environment. A recent article in Architectural Digest notes that artificial turf’s plastic material “traps heat during the day and holds it through the night, meaning runoff water will leave turf hotter than it would natural grass” - which can have negative effects on aquatic ecology.
Can artificial turf pollute the water or air? Evidence indicates cause for concern. Chemicals in tire crumb can volatilize into air or leach into rainwater. Some study results suggest that scrap tire materials in artificial turf may affect surface water or groundwater, warranting more study. Contaminants harmful to aquatic life, like zinc, have been found in stormwater runoff from artificial turf. For example, a study by the Connecticut Department of Environmental Protection noted high zinc concentrations in artificial turf stormwater runoff as a particular concern for aquatic organisms. It also noted the potential for leaching of copper, cadmium, barium, manganese and lead. A recent study found that a chemical derived from car tires, 6-PPD quinone, is lethal to coho salmon.
Recent research has identified per- and poly-fluoroalkyl substances (PFAS) in some artificial turf carpet materials. PFAS are a group of chemicals that are highly persistent in the environment; some can last for hundreds of years. PFAS have been found as drinking water contaminants in many states. Health effects documented for some PFAS include effects on the endocrine system, including liver and thyroid, as well as metabolic effects, developmental effects, neurotoxicity, and immunotoxicity. For more information, see TURI’s fact sheet on PFAS in artificial turf.
Health Concerns for Children
Chemicals in artificial turf fields are a particular concern for children. Children, including adolescents, are more vulnerable than adults to the effects of toxic chemicals. Their organ systems are developing rapidly, their detoxification mechanisms are still immature, and they breathe more air than adults relative to their body weight.
Concerns have been raised about chemicals in artificial grass carpet and in the infill that provides cushioning. Crumb rubber made from recycled tires (also known as “tire crumb”) is widely used as infill. It contains a large number of chemicals, many of which are known to be hazardous to human health and the environment; these include polyaromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), and toxic metals such as lead. Some of these chemicals are known or suspected carcinogens.
Other synthetic infills include ethylene propylene diene terpolymer (EPDM) rubber, thermoplastic elastomers (TPE), waste athletic shoe materials, and acrylic-coated sand. These materials also contain chemicals of concern, although the total number of chemicals and/or the concentration of chemicals of concern may be lower than those found in tire crumb.
Naturally derived materials used as infill can include sand, zeolite, cork, coconut hulls, walnut shells, olive pits, and wood particles. While these materials likely contain fewer hazardous chemicals than tire crumb, many have not been studied thoroughly. Some plant-based materials raise concerns related to allergies or respirable fibers, and zeolite and sand can pose respiratory hazards. Exposure to some types of zeolites may be associated with increased risk of mesothelioma, a type of cancer. For more information on chemicals in infill materials, see TURI’s report, Athletic Playing Fields: Choosing Safer Options for Health and the Environment and the Healthy Building Network’s Turf Hazard Spectrum.
In sunny, warm weather, artificial turf can become much hotter than natural grass, raising concerns of heat-related illness and skin burns for athletes playing on the fields. The Penn State Center for Sports Surface Research measured surface temperature for infill alone, artificial grass fibers, and a full synthetic turf system. They found that all the materials reached higher temperatures than natural grass. With more hot days associated with climate change, this is a growing concern.
Heat-related illness can be a life-threatening emergency. Experts note that athletic coaches and other staff need to be educated about heat-related illness and understand how to prevent it, including cancelling sport activities when necessary.
Some school districts are addressing the surface temperature issue directly. For example, the school board of Burlington, MA adopted a policy requiring that an infrared heat gun be used to determine field surface temperature. The policy states conditions under which athletes may use artificial turf fields and when their activities must be moved to grass fields. For example, if the National Weather Service issues a heat advisory, artificial turf cannot be used for P.E. classes if the air temperature is more than 85 degrees and the humidity over 60 percent – then only a grass surface can be used.
Increased rates of skin abrasions (turf burns) have been associated with playing on artificial turf. These skin abrasions, in turn, are a risk factor for serious bacterial infections. A study by the California Office of Environmental Health Hazard Assessment found a two- to three-fold increase in skin abrasions per player hour on artificial turf compared with natural grass turf. Studies have implicated artificial turf as a source of methicillin-resistant Staphylococcus aureus (MRSA) in athletes. MRSA infections are a substantial and growing source of concern for athletes’ health.
Analyze the full costs and benefits of the options available to your community. Start by reviewing your existing maintenance practices on grass fields. Is there an opportunity to improve existing maintenance before making an investment in a new system? If the community is ready to make a major capital investment, consider the option of rebuilding an existing grass field. As one example, Denison University rebuilt its natural grass varsity soccer field to address drainage issues; since rebuilding, it has had no cancellations due to rain.
Consider the full life cycle of a field. For example, evaluations should include the environmental and financial costs of maintaining artificial turf, as well as disposal and replacement after eight to ten years.
Consider how these questions align with related community goals or policies, such as climate change action plans.
If considering the option of removing artificial turf or wondering about how best to address a grass athletic field that has challenges like weeds or poor drainage, consult a professional who specializes in athletic field maintenance practices. A TURI report provides information about rehabilitation and rebuilding of natural grass fields and lists several consulting and educational organizations that focus on the use of organic management techniques.
Choosing natural grass
Part 2 of this blog series will look at natural grass as a safer alternative to artificial turf, including examples of schools and municipalities that have opted for natural grass athletic fields maintained with no or minimal synthetic fertilizers and pesticides. It will address comparisons of the options in terms of costs, playable hours, and environmental and health considerations.
About Susan Kaplan and Rachel Massey
Susan Kaplan is an environmental health lawyer and a professor at the University of Illinois Chicago School of Public Health. She contributes to projects at the Toxics Use Reduction Institute on a consulting basis.
Dr. Rachel Massey is Senior Associate Director and Policy Analyst at the Toxics Use Reduction Institute at the University of Massachusetts Lowell. Her work includes policy analysis at the state, federal and international levels, as well as work with communities to reduce toxics at the local level.