Washington lawmakers are asking the Environmental Protection Agency to weigh in on whether crumb rubber used in artificial turf fields in thousands of schools, parks and stadiums is safe for young athletes — citing a series of stories by NBC News.
"These stories and others raise questions among athletes and parents that crumb rubber on artificial turf athletic fields may present a pathway to exposure to one or more carcinogens," the House Committee on Energy and Commerce wrote in a letter to the EPA on Friday.
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The bipartisan panel gave the agency until Nov. 6 to answer 10 questions about what tests have been done to determine whether turf made from recycled tires poses a health risk and what investigators have found.
"Are you aware of any studies about carcinogens present in field sports generally?" one question asks. "Do data indicate that risk is greater for female athletes than for male athletes, for soccer players than for lacrosse, field hockey, or football players, and for one position in soccer more than for others?"
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The letter comes three weeks after the head of the EPA refused to answer a direct on-camera question about whether the synthetic surface is safe to play on.
"I have nothing to say about that right now," EPA Administrator Gina McCarthy told NBC's Stephanie Gosk when Gosk caught up with her in a Capitol Hill hallway.
Crumb rubber turf is made from pulverized tires — which can contain carcinogens — and green nylon blades of fake grass. No research has linked crumb or shredded rubber to cancer, and the turf industry says dozens of studies have shown the surface poses no health risk.
READ: The Original NBC News Investigation of Artificial Turf
University of Washington soccer coach Amy Griffin, who keeps a list of athletes who played on crumb rubber turf and have been diagnosed with various forms of cancer, welcomed Congress' intervention.
"They seem to be very well-intended questions that the deserve the attention of the EPA and only scratch the surface of how the materials in the synthetic fields were deemed okay to play on in the first place," she told NBC News.
Griffin now has 63 names on her list, most of them soccer soalies. The list is anecdotal, not a scientific data set.
While critics and supporters of crumb rubber turf don't agree on whether the surface poses a hazard, all sides want federal regulators to take a clear public position.