PFAS chemicals have been identified in synthetic turf, according to lab tests performed on several samples of the artificial grass that were shared with The Intercept. The presence of the chemicals, members of a class that has been associated with multiple health problems, including cancer, adds to growing concerns about the grass replacement that covers more than a thousand acres of parks, schools, professional sports stadiums, and practice fields around the U.S.
In one set of tests, the PFAS chemicals were detected in the plastic backing of two samples of the turf. In another, in which the “blades” of the artificial grass were analyzed, scientists measured significant levels of fluorine, which is seen as an indication of the presence of the chemicals.
“We’re seeing unexplained levels of fluorine-based compounds in all of the eight samples of turf grass blades we’ve looked at,” says Jeff Gearhart of the Ecology Center, a nonprofit environmental research group based in Michigan that tested the turf blades. The samples of the blades that tested positive for fluorine were made by two different companies, Shaw Industries and Turf Factory Direct.
Neither Turf Factory Direct nor Shaw Industries responded to requests for comment for this story.
PFAS chemicals are used widely to help with the molding and extrusions of plastic, according to a 2005 paper from the Journal of Vinyl and Additive Technology. The latest version of the synthetic turf, which is prized for its durability, is made with plastic polymers that are molded into the shape of grass blades when in molten form.
“When you extrude plastic, it’s like a cookie cutter,” explained Graham Peaslee, a professor of nuclear physics at the University of Notre Dame who has spent the last five years studying PFAS compounds. Without the PFAS, the rigid plastic used to make the turf durable clogged up the extruding machines that make the turf. “So they added fluorochemicals and now it runs through the extruders just fine.” While other chemicals can also ease the turf-making process, “the fluorinated ones work the best,” said Peaslee, who likened the PFAS in turf to “chemical hitchhikers” that are left over from the processing rather than used as ingredients.