In December 2007, nearly a decade after the city put its first artificial field in a park, the City Council held its first hearing on the use of artificial turf. Benepe showed up to testify, accompanied by Nancy Clark, parks' capital projects boss Amy Freitag and Celia Petersen, the Parks Department's head of specifications and estimates. Benepe described Petersen as "one of the world's experts on synthetic turf." In his testimony, Benepe provided a brief history of artificial turf, noting the desirability of fields that don't require "weekly mowing, watering, fertilizing, seeding, the use of chemical pesticides and herbicides or other time-intensive maintenance tasks."

AstroTurf was "quite durable," Benepe said, but "expensive and not perfect for competitive athletics" because it was "abrasive" and unyielding, making athletes "susceptible to knee injuries." Then came synthetic turf. "This new style of turf is technologically sophisticated," Benepe said, passing around a sample of the "much safer and more resilient" rubber-infill surface made from recycled tires.

"Now this typical artificial-turf field contains several layers, including a bottom layer composed of plastic sheeting, middle layers composed of crushed stone, plastic tubing for drainage and rubber padding for shock absorbance. Much of the value of these fields is actually below the surface," Benepe said.

"I should point out we are far from the only ones using synthetic turf," he continued, counting 150 fields in New Jersey and 30 in Connecticut. A turf craze had taken hold in the suburbs of Westchester County. "They're all sort of in a competition to see who can install more of these fields," Benepe said. Synthetic turf was going down at the new Giants Stadium, and it had already been installed at Rutgers, Columbia and Harvard universities. "If it's good enough for Harvard," said Benepe, "it's good enough for Harlem."

With organized sports more popular than ever, he explained, grass wasn't making the cut. Many more permitted hours were logged at fake fields than grass ones. He claimed natural fields needed to be closed for "at least four or five months—all winter long." (But in response to a City Limits follow-up, the Parks Department did not supply the name of one grass field maintained by the city that is closed for the winter. ) "We love grass," Benepe continued, saying most baseball and softball leagues prefer natural fields, while players of soccer were insisting on artificial turf. "Where we can support natural grass, we do, as in Marcus Garvey Park, where the Harlem Little League plays." He didn't mention that the Harlem Little League, not the city, built and maintained its one grass field.

Synthetic turf was encouraging exercise, Clark said, so the Health Department saw no need for the six-month moratorium being considered by the state legislature. More than half of the city's adults—and almost half of all its children—are obese or overweight, she said. Clark mentioned the report her agency had solicited on existing health studies. "We expect to complete our review by spring 2008 and will share our findings with the public and the Council."

Clark's testimony was followed by that of environmentalists who worried about the leaching of zinc from rubber-infill fields and the effect of storm water runoff on the city's troubled sewer system, youth soccer coaches who favored artificial turf because the city didn't maintain grass, and lawyers who warned about potential liability. Craig Michaels of the nonprofit environmental group Riverkeeper scratched his head over Clark's argument that the PAHs in the turf are already "very common" in the city. "I mean, that is a dangerous position to be taking," he said. "We are exposed to a variety of pollutants in New York City, but that cannot be used as justification to expose ourselves to more." Crain took his turn at the mic.

"What's desperately needed is not reports on existing research," he said. "What we need is new research." David Berman, unsurprisingly, disagreed. An avuncular representative for FieldTurf Tarkett, Berman said his company had been selling its rubbe-rinfill product for almost 15 years, and he had read plenty of studies. Enough was enough, he said, inviting Council members to eat a handful of the crumb rubber: "It won't taste great, but you cannot get sick from it, and it will come out of you exactly the way it went in."

Two weeks later, FieldTurf Tarkett hired Claudia Wagner, a high-powered lobbyist, to protect its interests at City Hall.

Just one month after the Council hearing, an internal Parks Department memo was leaked to the watchdog group NYC Park Advocates. It appeared to make New York the first city in America to stop installing the synthetic turf from recycled tires. "We are suspending the use of rubber infill synthetic turf in all Parks Capital Projects," read the design directive dated Jan. 14, 2008.

The Parks Department claimed the wording had been a mistake. "I incorrectly made a blanket statement," said Freitag, deputy commissioner of capital projects. "There is no change in the Parks Department's policy on synthetic turf." Turf with recycled-tire infill was still being put in parks, Freitag explained, but in the future the Parks Department would be "exploring the use of carpet-style" nylon turf, similar to the old-fashioned AstroTurf.

To critics of synthetic turf, Freitag's response sounded like backpedaling, or a strategy to avoid embarrassing questions about existing fields. For months before her memo, contracts had been modified to use alternative materials. St. Michael's Park in Queens, for example, was slated to receive recycled-tire turf, but that summer the new field was changed to a coated virgin- rubber product known as EPDM. The switch added $500,000 to the project's price tag.

One of the authors of the Jan. 14, 2008, memo was specifications chief Celia Petersen. The health concerns were not news to her. Petersen had received data sheets in July 2006 from an artificial-turf manufacturer named Forever Green; City Limits obtained the document in a Freedom of Information Law request.

"This product contains petroleum oils similar to ones categorized … as causing skin cancer in mice after prolonged and repeated contact," one data sheet read. "Any potential hazard can be minimized by using … protective equipment to avoid skin contact and by washing thoroughly."

A variation on the latter recommendation showed up on the Health Department's website: "As with any outdoor activity, it is recommended that after using the fields, people wash their hands before eating or drinking."

In the spring of 2008, Clark paid a visit to the Children's Environmental Health Center at the Mount Sinai School of Medicine. She briefed Landrigan and two colleagues on the turf issue and handed over a 171-page draft of the city's literature review. In a letter dated May 14 of that year, Landrigan and two other doctors at the center advised the Health Department to not release the "deeply flawed" report, calling it "superficial and one-sided." City Limits obtained the damning five-page letter through another Freedom of Information Law request.

The literature review "does not present a fair and balanced assessment of the issues surrounding the potential health hazards of synthetic turf," the letter read. "It is not up to the high standard of work that we have come to expect from the New York City Department of Health and Mental Hygiene in this administration." The letter went on to identify four "proven and potential" hazards of synthetic turf made from recycled tires. The first and "best established" was exposure to "excessive heat," with such medical consequences as "foot burns, dehydration and heat exhaustion." The doctors warned that watering the fields to cool them down could actually do more harm than good: "That can set the stage for skin infections," because "residual water droplets may act as bacterial incubators."

This observation led to a more in-depth discussion of the second risk: MRSA, the antibiotic-resistant staph infection that can be acquired through turf burns. MRSA clusters from turf burns had been reported in The New England Journal of Medicine, the doctors noted, and in the CDC's Morbidity and Mortality Weekly Report.

Lastly, the letter raised the risk of chemical exposures, acknowledging that the scientific literature was "much less well developed" on these hazards than on the dangers from heat and MRSA. "Several credible studies" had found the crumb rubber contained "known human carcinogens" and "neurotoxic chemicals," as well as lead, chromium and arsenic. The city's literature review relied on reports of human exposure to toxic chemicals from poured- or hard-rubber products, "very different from the particulate rubber infill found in synthetic turf fields" and therefore "only remotely relevant" to its topic.

The letter was blunt in its criticism: "Overall the draft report from [TRC Companies] on the health hazards of synthetic turf is incomplete, it relies on irrelevant data sources, it uses a deeply flawed approach to risk assessment, it glosses over glaring gaps in the data, and it far too readily dismisses proven risks to human health. It does not take into account the unique exposures and the special vulnerabilities of young children. It concludes quite inappropriately that absence of evidence of risk is evidence of no risk."

City officials continued to insist that the recycled- tire turf was "perfectly safe," a phrase repeated by Benepe at the April 2008 opening of the first athletic field meant to replace parkland lost to the new Yankee Stadium. "I would never endanger a child," he said. That artificial field, at P.S. 29 in the South Bronx, was put down on an asphalt schoolyard. At a ribbon-cutting ceremony, a small band of students played horns and drums. When not performing, they sat on folding chairs and sweated profusely. Several of the students remarked on the heat waves rising off the surface. In one corner of the field, behind a backstop, the city had installed a mister, or water sprinkler. "It allows players to cool down," Benepe explained.

Turf temperatures in New York City have been measured as high as 171 degrees by NYC Park Advocates, as the fields absorb sunlight and give off heat. "Heat stress and dehydration" were identified as synthetic turf 's "primary health concern" in the Health Department's literature review, but one study cited in the appendix made a finer point: "At temperatures above 120 degrees, it only takes 3 seconds to burn a child's skin severely enough to require surgery."

NYC Park Advocates released a leaked copy of the literature review on May 14, the same day as Landrigan's letter. City officials quickly responded that the report exonerated turf. Though the information contained in the review was far from conclusive, the media largely accepted the argument. The New York Times headlined its article on the report "Study Finds No Evidence of Risk in Synthetic Turf."

A Health Department spokesperson stressed that the review shouldn't have been released to the public: "We are still reviewing comments from staff and colleagues in the scientific community." That bothered Stuart Gaffin, a climate scientist at Columbia University who'd been studying artificial turf 's contribution to the heat island effect, the phenomenon of built-up cities being significantly warmer than surrounding rural areas. "People are being asked to comment on something that's very thin and anecdotal," Gaffin said.

As far as chemical exposure was concerned, the report concluded what Crain and Zhang had already said: The turf contained known carcinogens as well as some heavy metals linked to birth defects and mental retardation, but there was no scientific evidence that artificial turf posed a major health hazard.

It hardly calmed critics. "The report didn't resolve a thing," said Gotbaum, who resumed her call for testing and now supported a moratorium on new installations. "They spent $50,000 doing a review of the literature, which basically said, 'We don't really know.' We already knew that."