"SEATTLE -- Soccer dad Mike Miller prefers the smooth, cushioned surface of synthetic turf because his 13-year-old daughter can play year-round, even in the long rainy season that closes Seattle's grass fields.

But as Caty Miller and her teammates dribble, pass and shoot, their cleats kick up tiny bits of the ground-up rubber tires that are used as filler between the blades of artificial grass.

That has some health experts, activists and parents from Seattle to Chicago to Stamford, Mass. worried that children may be exposed to chemicals if they inhale or swallow the rubber granules, known as crumb rubber. Some are calling for a moratorium until the issue is more fully studied."

Phuong Le reports for the Associated Press May 17, 2009. [2]