When Carlos Torres takes his kids to the park, it's not a carefree excursion. As a former playground safety inspector, he is always on the lookout for potential hazards.
"I can't enjoy going to the park without looking at the slide and wondering if there's too much pitch or if there is a head entrapment," he says.
Torres is now an environmental health manager for the Los Angeles Unified School District. I meet him at Lemay Early Education Center in Lake Balboa, 20 miles from downtown Los Angeles. The kids at Lemay are 2 to 4 years old. On a tour, we pause to watch them sitting on the carpet in rapt attention while their teacher reads them "Chicken Little."
"The sky is falling, the sky is falling," reads the teacher as she holds up an illustration of a chicken getting bonked on the head by an acorn.
I visited Lemay to see a 5-by-15 foot patch of artificial turf in a small fenced playground.
Torres takes me outside and points to the small patch of bright green plastic grass. He bends down and pets it, looking for any rips in the fabric.
The original turf on this playground was removed after lead was discovered in fake grass. The lead, it turns out, was used to make the grass greener.
"My office, the office of environmental health, did some tests and we did not like what we found" Torres says.
Exposure to lead can damage organs and the nervous system, especially in young children.
The school district sued the synthetic turf manufacturers in 2008. The companies agreed to eliminate all lead form their products. But now there are other concerns about artificial turf.
Before we get into that, though, you'll need to know a bit about the history of fake grass.
In the 1950s, the Ford Foundation wanted to provide children with more outdoor play surfaces. So it partnered with the chemical company Monsanto. In 1964 they developed the first artificial turf field for a school in Rhode Island. They called it Chemgrass. One year later, Chemgrass was installed at the Houston AstroDome and renamed the more consumer-friendly AstroTurf.
Athletes hated it. The first generation AstroTurf was just a thin layer of carpet, sometimes over cement. "It was like playing on a rough carpet with very little resilience," says Rick Doyle, president of the Synthetic Turf Council.
Engineers softened the surface by lengthening the blades of fake grass, or Frass, another ill-fated product name. In 1997, the industry solved the cushioning problem: crumb rubber.
Crumb rubber is made by shredding and grinding used auto and truck tires into coarse granules. This is the stuff that raised new questions about safety.
Amy Stephan has three boys who play soccer and lacrosse on artificial turf in Great Falls, Va. When she first heard about the use of recycled tires, she started doing research. What she found disturbed her.
"I saw that there was data that showed that the tires yielded a whole lot of toxic materials," Stephan says.
Stephan read that some landfills classify tires as toxic. She wanted to know how a material could be regulated as toxic and be used as a play surface for children. Other parents wanted to know, too.
Rick Doyle of the Synthetic Turf Council says there is no reason to worry about the safety of crumb rubber. He cites studies done by the EPA and the Consumer Product Safety Commission as proof that crumb rubber is safe.
But public health toxicologist David Brown, with the nonprofit Environment and Human Health, disagrees. The EPA study tested only four fields, too small a sample size, Brown suggests, to definitively say that crumb rubber from recycled tires is safe for human exposure.
Brown wrote a 2007 report (PDF) on artificial turf for Connecticut that looked at samples from 12 fields. More than a dozen harmful chemicals were present in the samples, including known carcinogens. But Brown says his study was also too small to be conclusive.
He recommended the state impose a moratorium on building turf fields that use recycled tires until an appropriate evaluation of potential human health risks is established.
Since Brown's study New York's parks and L.A.'s schools have banned the use of recycled tires in playgrounds. Rhode Island, home of the very first artificial turf field, issued a statewide ban on tire crumb in artificial turf.
But the future of artificial grass looks bright. As home construction picks up and school funding increases, industry revenue is expected grow 12 percent a year over the next four years.