A college soccer coach may have unearthed a cancer cluster among soccer goalies, according to NBC News.

Photo Credit: Krivosheev Vitaly/Shutterstock

A new report from NBC News has prompted further worry about the safety of artificial turf and whether its ingredients — namely ground-up rubber car tires — can be the source of illnesses that can include cancers such as leukemia and non-Hodgkin lymphoma.
More than 13 million people play soccer in the U.S., some 4 million of them children and college athletes. Soccer complexes have become a staple of suburban America, and many of them opt for artificial turf over real grass. And those who play organized soccer may spend several days a week practicing and playing on artificial fields.
Artificial turf, first marketed in the early 1960s by Monsanto, has become increasingly popular in recent years as an alternative to natural grass. It has almost become the default playing surface for school and municipal fields and is an increasingly popular surface for college football and NFL stadiums over the past several decades.
Proponents of artificial turf like to claim that it’s environmentally friendly. After all, it requires no fertilizer, herbicides, pesticides, mower maintenance and water. Unlike the early forms of artificial turf, which was little more than a thick, green plastic mat rolled atop another surface (often concrete), newer artificial turf is well cushioned. The cushioning, often made of ground-up tires, serves an important purpose, making the playing field softer and more pliable, which may reduce sports injuries from ankle sprains to serious concussions.
But the same ingredient in the fake turf that makes it soft, called styrene butadiene rubber (SBR), could very well pose a toxic risk to those who use the fields and breathe the air around it. SBR, or “crumb rubber” as it is sometimes called, contains heavy metals and toxins such as lead, dioxin, carbon black, styrene, butadiene, and other known carcinogens. Those playing on the field are exposed to small, sometimes dust-sized “turf bugs,” which is the SBR that gets among the artificial grass blades. Soccer goalies, because their position requires them to often dive to the ground, and they get SBR crumbs in their eyes, hair, mouths, and in skin abrasions.
Critics of artificial turf also point out that being near the field might be hazardous. Those breathing the air nearby are exposed to vaporized volatile organic compounds (VOCs) that off-gas especially as the field gets warmer. Often called “headspace vapors” by those who play on the fields, artificial turf’s detractors say those gases, along with the turf bugs, are dangerous, if not deadly.
More Than a Coincidence?
Part of the NBC report revolves around Amy Griffin, a Seattle-area college soccer coach who visited two young female goal keepers, both diagnosed with non-Hodgkin lymphoma, at an area hospital. During a visit with one girl, Griffin overheard a nurse claim that she had administered chemotherapy to four soccer goalies that very week. Soon after, the girl, while receiving chemotherapy, wondered aloud if the turf bugs might be the culprit in their shared diagnoses. Another former high school soccer player, also suffering from non-Hodgkin lymphoma, now wonders the same thing:

During high school, she played on multiple teams at once, with two-hour practices five days a week, and games at least twice a week. Every day, she tried to clean the black rubber pellets, the “turf bugs,” out of the abrasions and burns she suffered as a goalkeeper on turf. Every day, to the chagrin of her mother, she shook them from her clothes and cleats onto the laundry room floor. She brushed them out of her hair, and spit them out of her mouth.

“The little black beads,” she said. “In the games and practices they’d get in my eyes, they’d get in my mouth, they’d get in my nose. My mom would get so mad at me because I’d go to the bathroom to take a shower, and the turf bugs would be everywhere.”

After her visit to the hospital, Griffin became a medical detective of sorts, collecting information on other athletes across the nation who have been diagnosed with cancers like lymphoma and leukemia. She’s identified 38 soccer players—34 who played goalie—as being diagnosed with cancers she thinks may be associated with the SBR used in the field.

While Griffin admits that the information she’s collecting might not show the statistical accuracy of scientific research, what she’s found is alarming nonetheless. However, further research may be very hard to do, as there’s a large variability in tire construction, making it hard to identify the possible contents used in SBR. With the mix of tire waste differing from field to field and different weather conditions also coming into play, it may make it hard to pinpoint how toxic any particular playing surface is.

Currently, no independent research has been done on artificial playing surfaces showing a definitive link to cancer, but several have showed a cause for concern. NBC lists three in particular:

  • One, published in 2013 in the scientific journal Chemospheres, which analyzed rubber mulch and rubber mats, concluded that, “Uses of recycled rubber tires, especially those targeting play areas and other facilities for children, should be a matter of regulatory concern.”
  • A 2006 Norwegian study evaluated inhalation, ingestion and skin exposure to crumb rubber in indoor fields. Researchers identified VOCs such as xylene, acetone and styrene, in the air above the fields. The study determined that inhalation of such compounds would not cause “acute harmful effects” to health, but that it was “not possible…to carry out a complete health risk assessment.” Researchers also concluded that oral exposure to artificial turf would not cause increased health risk.
  • Another 2013 study attempted to measure ingestion, inhalation and dermal exposure risk to users, and determined that the fields presented little risk. But researchers identified lead in the turf tested, including a “large concentration” of lead and chromium in one sample. “As the turf material degrades from weathering the lead could be released, potentially exposing young children,” the report states.

The Environmental Protection Agency and Consumer Product Safety Administration, which studied SBR fields and have insisted that the fields are safe in the past, are now calling their studies “limited,” according to NBC News. The agencies insist it’s a local decision whether or not artificial turf fields can be installed or used. In addition, the EPA told NBC News it would not pursue further studies into the safety of the fields.

Artificial turf manufacturers categorically deny there is any risk from the tire crumbs used in artificial grass. The industry complains that “hysteria and wild claims of imminent danger are a lot easier to make headlines with.”

Environmental groups such as Audubon Society and Sierra Club have expressed alarm about the impact on wildlife, especially birds. Replacing grass with plastic and tire crumbs destroys habitat, they point out, and the night lighting used in sporting fields negatively impacts birds’ reproduction, navigation and lifecycles.

The decision to use artificial turf poses a serious choice for communities in drought-plagued states like California, where it is believed that the watering of athletic fields can further exacerbate the ongoing water shortage. Artificial turf might seem like a simple solution, but such fields still need a lot of water, as they require periodic cleaning with water mixed with disinfectants. The SBR and plastic in the artificial fields can also get very hot in warmer months, so water cannons are used on hot days to cool the fields before practices and games.

In San Francisco, residents are debating whether to convert meadow-grass soccer fields in the Golden Gate Park Historic District into a massive, lighted, soccer-field complex made of SBR turf. The city’s Department of Recreation and Park says it has little choice but to use the turf, considering tight water restrictions. However, opponents have gathered enough signatures for a local ballot measure on the issue.

The measure, up for vote in November, would require the city to keep up all sports fields in the western section of Golden Gate Park as natural grass, and would prohibit night sports lighting in that same area. There is also an opposing initiative on the ballot that approves renovating the Beach Chalet soccer fields by installing artificial turf and lighting.

Hearings on the park project go back four years, and the two sides have fought over the issue while the Recreation and Park Commission and other governmental agencies have granted the fields’ approval without even demanding so much as a comprehensive environmental review.

San Francisco attorney Richard Drury joined with the Sierra Club to file a lawsuit against the installation of artificial turf. Drury’s children play soccer and he’s worried about the toxic risk to them.

“SBR presents numerous environmental risks – heavy metals, such as lead, dioxin, carbon black, styrene, butadiene, and other known carcinogens,” he told Mike Murphy of Earth Island Journal.

Of particular concern to Drury were the headspace vapors. As he argued in court, the inhalation of these toxic fumes would pose a substantial cancer risk to those who regularly use the fields, as they would from breathing the air near refinery plants. And some players, said Drury “use the fields four times a week” and would especially be at risk.

Drury is “shocked that the city would consider this alternative,” especially when some nearby municipalities avoid SBR by using other infill materials such as “cork-o-nut,” a mix of cork and coconut coir. The city of Los Angeles, Drury notes, prefers to use colored sand for many recreation fields. And New York, where residents have made an issue over artificial turf, currently has a de facto moratorium in place on artificial turf with waste tire infill.

See the NBC News segment below: