A group of residents in the Olentangy Local School District is raising concerns about the safety of artificial turf fields that booster groups plan to install at all three high schools by the end of the year.

A group of residents in the Olentangy Local School District is raising concerns about the safety of artificial turf fields that booster groups plan to install at all three high schools by the end of the year.

Critics say they're worried that artificial turf fields could result in more injuries and possibly even illness from exposure to the synthetic materials that make up the fields.

But turf proponents, including leaders of the Olentangy turf committee spearheading the project, say the new playing surfaces are just as safe as grass, and more cost-effective to boot.

Scientific studies on the safety of turf fields have shown mixed results as the materials used in the surfaces have evolved.

Modern Field Turf surfaces such as those being pursued by the turf committee are composed of layers of silica sand and crumb rubber, mainly from recycled tires. The top grassy layer is made from a woven fabric material called polypropylene.

Neal Gearinger, an outspoken critic of the turf project, said he worries that repeated exposure to the rubber and synthetic turf fibers, which contain trace amounts of lead and other heavy metals, could lead to unforeseen health problems.

In fact, the Centers for Disease Control issued a health advisory in 2008 warning that some turf surfaces made from nylon fibers contain sufficient levels of lead to "pose a potential public health concern."

But the advisory noted that newer turf surfaces, such as those being pursued in Olentangy, contain "very low levels of lead" -- far below levels generally considered problematic.

When referencing a study of turf conducted in New Jersey, the CDC noted "no cases of elevated blood lead levels in children have been linked to artificial turf on athletic fields in New Jersey and elsewhere."

Still, Gearinger contends studies are ongoing and that any level of exposure to potentially harmful substances should be avoided. "We have so many environmental hazards that we can't get away from every day," he said. "Why not avoid adding one more?"

Even groups advocating for turf fields advise that athletes should wash their hands to remove traces of rubber before eating to avoid ingesting the materials. Regardless, there is no evidence to suggest that incidental ingestion could cause illness.

The potential for student injury is another sticking point for turf opponents. Gearinger and others say the evidence shows the physical properties of turf can lead to more injuries.

One recent study by research-ers at Stanford University did find an increase in instances of torn ACLs, a major ligament of the knee, when playing on turf.

Some theorize football cleats grip the turf surface more closely than grass, causing more muscle twists and tears.

But results are mixed. A three-year study of 24 college football teams, published in 2010 by researchers at Montana State University, found injuries were rarer and less severe when playing on turf.

Grass surfaces frequently are uneven, with dips and bumps that can cause athletes to trip or twist an ankle, said Mike Bull, a turf committee leader and member of the Orange High School athletic boosters.

The Dublin City School District began adopting turf fields in 2004. District spokesman Doug Baker said trainers love the fields because they see fewer injuries on the level playing surfaces.

Dublin is just one of many neighboring school districts to install turf in recent years. Olentangy athletes already frequently play on turf when visiting Westerville, Worthington, Upper Arlington, Gahanna, Reynoldsburg, Bexley, Grandview Heights and others.

The potential for burns also has been raised, as synthetic turf retains more heat than grass.

But Bull said watering a turf field for 15 to 20 minutes before play on particularly hot days can lower its temperature dramatically. He added most games are played in the fall when temperatures are beginning to dip.

A plan to install turf fields at all three of the district's high schools was put on hold June 20 when the school board rejected a joint-financing plan proposed by the turf committee, forcing booster groups to shoulder the burden of funding all three fields at high interest rates.

The committee now is targeting November for construction of the fields, immediately after the football season.

Supporters say the fields would generate new revenue because they could be used much more frequently and could host tournaments.

They also say turf, which doesn't need to be trimmed or fertilized, is cheaper to maintain than grass in the long run.