Turf concerns

Unlike grass fields, which cool the surrounding air by reflecting sunlight and evaporating water, artificial fields absorb and reradiate the sun's heat. Synthetic turf fields are some of the hottest places in the city, said Dr. Stuart Gaffin, associate research scientist at the Center for Climate Systems Research at Columbia University, who discovered this from NASA satellite maps when doing research on the urban heat island effect.

Concerns grow but the grass doesn't

Over the last two summers, researchers visited the hot spots identified in the maps and measured just how hot the city's synthetic turf fields can get: as high as 130 to 140 degrees Fahrenheit. Synthetic turf is hotter than asphalt, said Gaffin.

This could have a particularly negative impact on temperatures in communities where a significant amount of natural surface is replaced by synthetic turf. One such example is the area around the new Yankee Stadium. The stadium occupies the site of Macombs Dam Park, a 20-acre rectangle that formerly contained well-worn soccer and baseball fields and a running track and was bordered by hundreds of mature trees. To replace some of that park's facilities, the city will build an artificial turf soccer field and track on top of a parking garage.

Another consideration is the impact of artificial turf on the city's combined sewage overflows. In most of the city's sewer system, storm runoff combines with household sewage. During huge downpours, sewage treatment plants cannot handle the added rainwater, and untreated waste overflows into the harbor and rivers. Grass and dirt soak up rain, but synthetic turf fields, which are designed to drain quickly, very efficiently funnel rainwater into the sewage system.

Replacing natural fields with synthetic turf runs counter to the city's goal of increasing natural areas and permeable surfaces as a way to reduce stormwater runoff. This strategy is part of Mayor Bloomberg's sustainability blueprint, and likely to be included in the stormwater management plan the city is required to adopt by the end of the year.

From the NY Times: Groups Urge a Moratorium on City Use of Artificial Turf

In a letter to the city’s parks and health commissioners, dated Thursday, the groups say the installation of such fields should be suspended pending the results of a review of health risks being conducted by the health department.

The letter was signed by Betsy Gotbaum, the public advocate, who is a former city parks commissioner; Christian DiPalermo, the executive director of New Yorkers for Parks; and members of the Natural Resources Defense Council and New York Lawyers for the Public Interest.

Adrian Benepe, the parks commissioner, is an advocate for turf fields. He has said the surface is safe and cheaper and more durable than grass.