As the school year came to a close last spring, artificial turf generated national headlines when a handful of older synthetic playing fields in New Jersey were closed because the turf fibers appeared to contain high levels of lead. Debates over the safety of both older and newer synthetic surfaces have continued through the summer.

The environmental concerns began when a cleanup at a scrap metal yard that neighbored an older field in Newark, N.J., found that the nylon fibers on the turf contained lead levels eight to 10 times higher than state standards for soil. The field was closed and replaced with a new AstroTurf system featuring lead-free nylon fibers.

All of the surfaces with high lead levels in New Jersey were older AstroTurf fields containing nylon fibers that were installed by Southwest Recreational Industries. The company went out of business in 2004 and the brand is now owned by GeneralSports Venue, which installed the replacement field in Newark.

Despite the field closures and turf replacements, members of the synthetic turf industry say the lead level findings are misleading. Industry leaders explain that the lead used in fields (as part of the pigment that colors the turf, especially in line markings and logos) is lead chromate, which differs from lead carbonate found in old paint, and presents little risk.

"The pigment used to color the nylon fiber contains lead chromate, a component used to extend the yarn color lifespan," the Synthetic Turf Council (STC) said. "Lead chromate is a highly insoluble compound with extremely low bioavailability, which is diluted, extruded with resins, and microencapsulated within the nylon fiber. In fact, OSHA requires no protective measures when handling the turf fibers.

"Extremely low bioavailability means that even if the compound were to be ingested, it is very difficult for it to be absorbed within the body," the STC continued. "There is no known evidence that this poses any health risk."

Uncertain over the extent of any danger, the New Jersey Department of Health and Senior Services (NJDHSS) conducted its own tests into the way lead from synthetic turf would be absorbed by the body. It reported that the levels of digestible lead were similar to that found in household dust and soil samples and could result in increased blood lead levels. Synthetic turf manufacturers, however, countered that New Jersey's tests show a child would need to eat nearly 100 pounds of turf to have increased blood lead levels.

The ensuing media coverage caught the attention of consumer protection groups, elected officials, and state health officials across the country. Although lead dangers serve as the flash point, the conversation also includes the safety of other components of artificial turf.

A non-profit health advocacy group in Connecticut called Environmental and Human Health, Inc., is concerned about the crumb rubber used in newer fields, which is constructed of ground up recycled tires. The organization has asked for a moratorium on installing new fields after a laboratory study it commissioned reported that heated crumb rubber gives off vapors containing at least four organic chemicals that can irritate eyes, skin, and lungs. One of the chemicals--butylated hydroxyanisole--has been linked to cancer.

No data is available, however, on the level of exposure athletes face. It is also unclear how the chemicals might be absorbed by the body. Rick Doyle, President of the STC, adds that the study was not done under realistic conditions since the tests were conducted solely on crumb rubber in a laboratory and not on an actual field.

And more research is on the way. After the lead contamination discoveries in Newark, the Environmental Protection Agency (EPA) and the U.S. Consumer Product Safety Commission (CPSC) began investigating lead levels of different types of artificial surfaces, and anticipate releasing a report sometime later this summer. Connecticut will spend $200,000 to do field studies on artificial turf that is composed of crumb rubber.

As a result, legislators in Minnesota, New Jersey, and New York have introduced bills that would bar the installation of any new artificial turf fields until those states complete health and environmental studies. In California and Connecticut, bills call for health studies but don't prohibit new construction.

Meanwhile, turf manufacturers continue to call the concerns unfounded. "For over 40 years, there has never been a case of human illness or environmental damage arising out of any of the materials used in synthetic turf," Doyle told the Chicago Tribune.

At West Alleghany (Penn.) High School, a new artificial surface was installed in 2007. "As soon as I read the reports out of New Jersey, I called our field vendor," says Dave McBain, Athletics Director at West Alleghany. "I asked questions and they reassured me that their filament, fibers, and rubber have been deemed safe and that there is no risk for us at all."

McBain, who is also a member of the Pennsylvania Interscholastic Athletic Association Sports Medicine Advisory Committee, says communication is the key to heading off concerns. "That's done by having good information from the vendor that ensures the field is of high quality, safe, and free from the residual problems the fields in New Jersey had," McBain says.

"When we were installing our field, I distributed any vendor replies to parents, boosters, and coaches," he continues. "I handed out those documents as they appeared on the company's letterhead. That way, parents could do their own research and contact that vendor directly if they didn't understand something."