A standout Tacoma, Washington, high school soccer player died last year at 24, following a seven-year battle with Hodgkin's lymphoma, according to an article in the Tacoma News Tribune.

The man’s parents worry about the players who will follow after him, running, rolling and diving into the more than 11,000 artificial turf soccer fields around the country — including at more than a dozen schools in the Tacoma School District — just as their goalkeeper son did.

Most of those synthetic turf fields are cushioned with a material called crumb rubber, made from ground-up used tires. The tiny pellets are loosely distributed as infill between artificial blades of grass woven into a carpet-like base. Modern turf fields are the successors to the original 1960s-era AstroTurf.

Athletes who play on today's fields that use crumb rubber infill are familiar with the "little black dots" that are kicked up during a game or practice, reported The News Tribune.

There is a growing chorus of concern about whether the rubber specks that stick to skin, hair and clothing, and that get in players' eyes, mouths and open wounds, contain toxic substances that contribute to cancer in young athletes.

Source: The Tacoma News Tribune