Recently, NBC News published an article about the possibility that artificial turf fields cause cancer. The subject of scrutiny, in this case, was the tiny pellets of recycled tire, called crumb rubber, which gives the turf its bounce. Astroturf, the synthetic grass that was first developed back in the 1970s and installed at the former home of the Houston Astros, is rough on athletes who often fall down (with force!) onto the field, like football and soccer players. Crumb rubber adds much needed cushion to the synthetic grass, turning potentially harmful collisions with the ground into less jarring impacts. However, the NBC report indicates that the crumb rubber, or turf bugs as it is colloquially called, can cause cancer.
Risk of heavy metals
This supposition is based largely on concerns regarding the chemical composition of the crumb rubber, which are spurred by the fact that it is made from recycled tires. Some tires contain trace amounts of heavy metals, which are left over from the manufacturing process and could purportedly include arsenic, cadmium, chromium, lead, mercury and zinc. The NBC report seemed to indicate that few studies of repute have been conducted to determine the risk of exposing people and the environment to these chemicals. However, that is simply not true. Although the EPA has not conducted any new testing on crumb rubber since the introduction of this material in the early 2000s, many other organizations, communities and states have conducted their own studies to determine the toxicity of crumb rubber.
Just recently, Tabor Academy, a co-ed preparatory school in Marion, Massachusetts, wanted to replace one of its playing fields with artificial turf. Tabor is located right on the coast, and its low water table meant that the football field would often flood, limiting the number of days that athletes could practice and leading to the cancelation of many games over the years. In order to stay competitive, Tabor decided that artificial turf would solve many of the inconsistencies associated with its field, but the town of Marion was extremely skeptical. Purists and largely ecologically-minded, the residents of Marion were concerned about the prospect of dumping thousands of pounds of ground up tires so close to the ocean. Many people believed that the crumb rubber would contaminate local groundwater and eventually seep into nearby marshes, causing devastating environmental damage.
Studies from the school by the sea
In order to determine the impact of crumb rubber on Marion’s delicate, coastal ecosystem, Tabor commissioned CDM Smith, a consulting firm that focuses on water and environmental concerns, to evaluate the impact of artificial turf on the water. The company collected a turf sample from the G. Richard Duffy Athletic Field and tested it using what is called the synthetic precipitation leaching procedure. Water samples were also collected from the field’s underdrain outfalls during four separate rain events. All four water samples as well as the turf sample were tested for arsenic, cadmium, chromium, lead, mercury and zinc, and the results indicated that, based on the U.S. Environmental Protection Agency’s criteria for freshwater aquatic life and drinking water, the artificial field was not a source of metal concentrations.
Four years prior to Tabor Academy’s evaluation of artificial turf, another group conducted a study that analyzed the concentration of hydroxypyrene in the urine of soccer players after a match on artificial turf with crumb rubber. In order to acquire accurate readings, the researchers tested the urine of seven nonsmoking soccer players over a three day period surrounding play on artificial turf. The urine samples were tested for 1-hydroxypyrene, which is a potentially hazardous material associated with the shredded tire backfill. Interestingly, the study concluded that if there was any exposure to this chemical, then the uptake was very limited and within the range of uptake that is normally associated with other environmental sources and or diet.
A new angle
Still, despite this evidence that crumb rubber is safe, the NBC report touches on an area that does require additional exploration: the effect of direct contact of crumb rubber with an athlete’s bloodstream. Goalies in particular are often required to dive for the ball, and this can lead to open wounds over the course of a game. Unfortunately, the blood from these injuries can make them sticky, which means that crumb rubber adheres to the site and could potentially cause a heightened uptake risk. From this perspective, additional testing would likely prove beneficial, and a recent call for testing has attracted the attention of many materials testing organizations.
Polymer Solutions, a materials testing firm, can provide independent data from GC-MS, extractions, and LC-MS so artificial turf clients can confirm the safety of their product in an objective and scientifically rigorous way.
This is undeniably a sensitive issue, and anything that could potentially expose people, especially children, to a carcinogenic agent must be taken seriously. However, it is also critical that issues like this are approached rationally and from a scientific perspective – alarmist sensationalism will lead to nothing but fear and anxiety. Additional testing of crumb rubber should commence soon to address any current concerns related to the health risks posed by this material.