Two senators have urged federal officials to lead an "independent investigation into the health risks of crumb rubber" turf, a surface made of recycled tires used on playgrounds and athletic fields across the country.
Democratic Sens. Richard Blumenthal of Connecticut and Bill Nelson of Florida sent a letter to Chairman Elliot Kaye of the Consumer Product Safety Commission asking the CPSC to "devote additional resources to conclusively determine whether these products can be safely played on by young children and people of all ages."
They note that the CPSC said in September it would provide technical assistance to an evaluation of crumb rubber now being conducted by the California Office of Environmental Hazard, but said the CPSC should "lead the independent federal investigation on this important matter."
Related: Read the Original NBC News Report
Related: Watch the Original NBC News Report
CPSC spokesperson Scott Wolfson said the agency had "deep respect" for Sen. Blumenthal. "He has been a champion of child safety for many years. We have already begun working on a response for the Senator, and it will be timely."
Wolfson said the CPSC continues to plan to provide support to California's upcoming study.
The two senators are the latest Congressional officials to call for research on crumb rubber since NBC News begin airing and publishing a series of reports on the playing surface more than a year ago.
In October, the House Committee on Energy and Commerce sent a letter to the EPA asking the agency to weigh in on whether crumb rubber is safe for young athletes, and cited the NBC News reports. The bipartisan panel gave the EPA till Friday, Nov. 6 to answer the 10 questions about what tests have been conducted to determine whether the product poses any health risk and what investigators have found.
On Friday, EPA spokesperson Liz Purchia told NBC News that the agency was "in the process of responding" to the Energy Committee's list of questions.
Purchia said "new science" is needed to answer questions about turf safety and that "existing studies do not comprehensively address the recently raised concerns about children's health risks from exposures to tire crumb."
"We know communities want more information as they make decisions to repair and replace their playing fields or as they consider a number of alternate materials available in the market today."
The EPA is "actively engaged" with the California study, said Purchia, and EPA scientists have been providing technical advice to study planners. "Our hope is, that by working with the state of California and other federal and state agencies, we will optimize our ability to gather sound, scientifically credible data on potential risks and exposures, as well as identify critical remaining research gaps."
Purchia cited previous studies done by federal, state and local agencies and said "none of these studies showed any elevated health risk from playing on fields with synthetic turf or crumb rubber."
No studies have linked crumb rubber to cancer or any disease, but some experts believe more tests are needed to determine whether the product is safe for use. The turf industry says that dozens of studies have shown there is no health risk, but also believes the federal government should take a clear position.