Seattle soccer coach Amy Griffin appeared on NBC news last fall for voicing her concerns about artificial-turf fields. Specifically, the associate head coach of the University of Washington’s women’s team had been worried about “crumb rubber”—tiny black pieces of used tires—which is being used as infill. She had compiled a list of 38 young players—34 of them goalkeepers—who had been diagnosed with non-Hodgkin lymphoma. Griffin couldn’t help but wonder if those athletes’ exposure to “tire crumb”, which contains multiple toxic chemicals and carcinogens, had put them at risk.
Since October, her list has grown to 89 names. Although it’s difficult to prove a direct link between exposure to crumb rubber and cancer, Griffin still isn’t convinced that the substance used on synthetic-turf fields is safe, especially for young kids.
“We don’t really know enough about the toxins in this stuff,” Griffin says in a phone interview. “You can smell it when it gets hot. Players say things like, ‘We get it [the crumbs] in our eyes’ or ‘Every time I play indoors, I have a hard time breathing.’ If we don’t know how safe it is, then why can we sprinkle it around on our playing fields?”
The new generation of artificial-turf fields, including some in Greater Vancouver, often contains crumb rubber, which acts as fake soil, supporting the synthetic blades of grass and softening the surface. The crumbs can become airborne and get inhaled, ingested, and tracked into cars and homes on clothes and athletic gear. Aside from their potentially negative effect on the environment, rubber from pulverized tires contains several chemicals that are known or suspected to cause health “effects”, according to a March 2008 issue of Environmental Health Perspectives.
“The most common types of synthetic rubber used in tires are composed of ethylene-propylene and styrene-butadiene combined with vulcanizing agents, fillers, plasticizers, and antioxidants in different quantities, depending on the manufacturer,” the article states. “Tire rubber also contains polyaromatic hydrocarbons (PAHs), phthalates, and volatile organic compounds (VOCs).”
Specific compounds in the material, according to a 2009 study by the U.S. Environmental Protection Agency, include acetone, benzene, halogenated flame retardants, methyl ethyl ketone, phenol, styrene-butadiene, and trichloroethylene, as well as barium, cadmium, lead, mercury, and latex. (Some people have also voiced concerns over antibiotic-resistant staph bacteria being associated with synthetic turf.)
Environment and Human Health, Inc., a nonprofit organization in Connecticut, reports that the strongest data looking at a link between crumb rubber and cancer come from the France-based International Agency for Research on Cancer’s study of the rubber industry. “Strong and sufficient evidence for cancer in humans was demonstrated in a series of epidemiology studies of rubber fabrication facilities throughout the world,” the EHHI website states. “One especially relevant report addressed exposures in a factory in Taiwan that made tire crumbs. In that study, mutagenic actions that were four to five times higher than in controls were shown in extracts of particulate matter collected in the air.”
Studies into the effects of crumb rubber on human health, particularly in children, are limited. At any single site, there can be substantial variation in the materials used and the concentrations of contaminants measured, the EPA research found. And those that do exist suggest that chemical exposures from crumb rubber in synthetic turf do not pose a public health hazard.
“On average, concentrations of components monitored in this study were below levels of concern,” the EPA report states. “However, given the very limited nature of this study (i.e., limited number of components monitored, samples sites, and samples taken at each site) and the wide diversity of tire crumb material, it is not possible to reach any more comprehensive conclusions without the consideration of additional data.”
Thomas Soulliere, City of Vancouver director of recreation, says that the municipal body consulted with Vancouver Coastal Health a few years ago regarding this issue. (The Vancouver park board rents out nine artificial-turf fields, including two at Andy Livingstone Park and two at Trillium Park.)
“They stated they had done research—a literature review of other jurisdictions in the U.S. and Canada and consulted with other medical health offices in the region—and determined there was no health rationale for removing or replacing our artificial-turf fields,” Soulliere says by phone. “The estimates in terms of any potential exposure to any dangerous chemicals were very low, and there wasn’t a reason to be concerned.”
Vancouver Coastal Health manager of environmental health Randall Ash concurs. “When we looked into this in 2008 or 2009, there was no reason to be concerned,” he says in a phone interview.
In West Vancouver, two of three artificial-turf fields that were installed in 2012 contain crumb rubber. Communications director Jeff McDonald says the district has had only one inquiry from a community member about the safety of the material.
“We take any kind of health concern seriously, and we’ll continue to keep our eye on it,” McDonald says by phone. “It’s early days, this issue; if it continues to grow, then we’ll monitor it, but at the moment we have had a lot of positive reinforcement and feedback about those fields. Health Canada has deemed crumb-rubber field systems safe enough to be sold in Canada. If Health Canada finds significant risks in the future, they will issue a product recall or ban its sale in Canada, and we would respond accordingly.”
Others say more research is warranted.
“It intrigues me from a scientific perspective,” says Hugh Davies, associate professor at UBC’s school of population and public health, in a phone interview. “You’ve clearly got a product that was designed for one use and it’s been repurposed, and you’ve got a totally different population that’s having exposure to it.…It’s being left out in the environment and breaking down even further. Very little study has been done so far, and what has been done hasn’t been long-term, so it seems to warrant more investigation.”
John Spinelli, department head of cancer-control research at the B.C. Cancer Research Centre, notes that it’s difficult to extrapolate from the limited studies to date that all fields are safe.
“More research needs to be done to establish that the fields in B.C. also have levels below detection,” he tells the Straight. “It would take a massive and expensive research study to relate the fields to cancer risk, but given the anecdotal evidence and the fact that children are involved, it seems worthwhile.”