The increasing importance attached to scholastic sports programs has fueled demand for uniform, all-season sports fields, and many communities are considering the installation of synthetic turf as a solution. This type of turf is typically composed of a base layer for drainage made from gravel or stone, sand, a backing layer, plastic grass carpet and turf fibers (blades) and infill material used to keep the turf fibers upright and provide cushioning.
Synthetic turf fields have been around since the introduction of “Astro Turf” at the Houston Astrodome in 1965. Since then, tens of thousands of turf fields have been installed in communities around the country.
A typical football field utilizes 100-120 tons of ground up used tires (crumb rubber) to cushion the field and keep the plastic “grass blades” upright.
Crumb rubber dust and small pieces are easily inhaled or swallowed as they become disturbed during game play.
Tires can release hazardous chemicals, oils and heavy metals that can persist in the environment and pose a threat to student athletes.
Statistics show that injuries are actually more common on synthetic turf surfaces.
On a hot sunny day, synthetic fields can reach a temperature of 180-200º F.
The benefits of synthetic turf, as touted by their manufacturers, include 24/7 use, all-weather play, a safer surface resulting in fewer injuries, and a maintenance-free field with no need for mowing, pesticides, fertilizers, etc. This pitch makes the allure totally understandable.
The emerging science presents a more sobering reality. A typical football field utilizes crumb rubber infill from as many as 40,000 recycled tires (100-120 tons). Tires are made from some very toxic chemicals, including the known carcinogens arsenic, benzene, carbon black (which makes up to 40% of a tire), 1,3 butadiene, TCE, and cadmium, as well as neurotoxins, lead and mercury. Crumb rubber dust and small pieces are easily inhaled or swallowed as they become disturbed during gameplay.
The green plastic field “carpet” and “grass blades” of synthetic turf are frequently impregnated with or treated topically with antimicrobial chemicals (legally defined as pesticides) to address body fluid contamination and antibiotic-resistant staph infections like MRSA. Naturally maintained grass fields require no chemical use and beneficial soil microbes deal effectively with body fluids.
Anti-static chemicals are also frequently used, as well as flame retardant chemicals, to address the high flammability of rubber and increasing acts of arson vandalism, and perfluorinated chemicals, to facilitate the manufacturing process of plastic grass blades going through an extruder.
Statistics show that injuries are actually more common on synthetic turf surfaces, especially those that are not constantly maintained for resiliency. The G-max rating - the ability to absorb impact - changes as the materials are compacted, often leaving an unsafe, harder surface that makes injuries more likely and more severe. Common injuries include joint trauma (especially ankles and knees), concussions, “turf toe,” and unusually large skin abrasions which are more prone to infection. These are some of the reasons that the majority of professional athletes prefer natural grass.
Then there are heat issues. Studies from Brigham Young University showed that synthetic turf averaged 37 degrees hotter than asphalt and 86.5 degrees hotter that natural grass. On a hot sunny day, synthetic fields can reach a temperature of 180-200 degrees. Dehydration, heat stroke and other serious heat-related illnesses and second degree burns occurring on the soles of the feet of athletes have spurred turf manufacturers to sell water canons for cooling the fields, even though the water only reduces the temperature for about 20 minutes, at which time the process has to be repeated. Heat also increases the outgassing of volatile chemicals, which makes them more problematic as an inhalation exposure.
Young children are especially vulnerable to toxic exposures from synthetic turf due to their play habits close to the ground and typical hand-to-mouth behaviors. Due to their small size, they receive proportionally greater doses of chemical contaminants than adults and their immature organs and developing bodies make it more challenging for them to detoxify or eliminate certain toxins. Toxic substances in the crumb rubber can be inhaled, absorbed through the skin or accidentally ingested.
Lastly, there are a growing number of reports of higher than usual cases of lymphoma and leukemia among athletes playing on synthetic turf, especially soccer goalies, who regularly dive onto the turf, releasing dust and infill particles. To date, no studies have been conducted to confirm a link, but common sense tells us that chemicals in tires that are linked to cancer should be avoided.
Federal laws that govern disposal of solid and hazardous waste gives the U.S. Environmental Protection Agency (EPA) the authority to control hazardous waste from “cradle-to-grave,” including used rubber tires. However, these federal regulations state that the recycling of a hazardous waste product into a consumer product automatically exempts it from regulatory requirements even if the end product created is more toxic than other similar products on the market. This means that no monitoring is required for these new products that have been manufactured from recycled hazardous waste, such as synthetic turf crumb rubber infill or recycled rubber playground surfaces.
The US Environmental Protection Agency (EPA) and Consumer Product Safe Commission (CPSC) have removed safety assurances of synthetic turf from their websites. Both houses of Congress have called for further studies and on February 12, 2016 the EPA, the CSPC and the Centers for Disease Control and Prevention/Agency for Toxic Substances and Disease Registry (ATSDR) launched a multi-agency action plan to study key environmental human health questions regarding synthetic turf. Results are pending.
Additional concerns about the eventual disposal of artificial fields, potential legal liability, heat island effects and the loss of environmentally beneficial natural turf, which sequesters carbon dioxide and reduces global warming have convinced many decision makers to reconsider plans for synthetic turf fields.
Synthetic Turf Resources
An excellent brochure entitled “The Dirt on Turf” is available from Red Hen Turf.
A comprehensive website with excellent resources is available at www.safehealthyplayingfields.org
The Children’s Environmental Health Center at Mt. Sinai in NY has developed a science-based consumer guide to artificial turf and the health concerns.
The ChildSafe School - This award-winning program promotes and provides a framework for a comprehensive approach to reducing environmental toxins in schools. Core issues include diesel exhaust from idling school buses, pesticides used on school grounds, cleaning products for interior use and emerging environmental health issues, including artificial turf fields, wireless technologies and fragrances.
How Green Is My Town? - This online program, which addresses the three inextricably linked issues of sustainability, climate change and environmental health, provides a blueprint for 50 discreet issues, and contains the resources, templates, science and other essential tools to help every town achieve its environmental priorities.
Related Podcasts from Green Street
Toxic Playing Fields with Amy Griffin