STAMFORD — Health officials have closed the artificial turf field at Stamford High School's Boyle Stadium after tests revealed elevated levels of lead in its nylon fibers that exceed direct exposure criteria established for soil.

Health officials said they believe the potential for lead poisoning for users of the field to be small, and are closing the field as a precautionary measure.

Superintendent of Stamford Schools Joshua Starr, in a letter posted on the schools' Web site, stated the field will remain closed until it can be tested by the Environmental Protection Agency.

"As you may know, the city maintains other newer synthetic turf fields at Stamford High, Westhill High and Rippowam Middle School. Those fields are not Astroturf and there is no reason to believe they pose any health risk," Starr stated in the letter.

The tests were conducted on the 11-year-old artificial turf after similar fields in New Jersey were found to have high levels of lead, Barnes said.

"Those fields were similar both in construction, materials and in vintage," Barnes said. "And because of that we decided to test the field (at Boyle Stadium) for lead."

Brooks Environmental Consulting LLC of Norwalk and Schneider Laboratories of Richmond, Va., both tested the artificial turf field's playing surface and the pad beneath used for shock absorption.

Both tests found lead at nearly 4,000 parts per million in samples of the field's turf, and 120 parts per million in the absorption pad. About 500 parts per million is the maximum for a safe level of exposure, according to the federal Environmental Protection Agency.

The EPA has not made recommendations on levels of lead that are safe for artificial turf. Because of that, the health department is using standards for residential direct exposure in soil.

Barnes said the lead was most likely used in the turf's pigment, which is encapsulated within the nylon fibers.

Barnes said the field at Boyle Stadium will most likely be replaced with a synthetic turf similar to that planned at West Beach, Lione Park and Westhill High School. Barnes said these fields are manufactured using polyethylene fiber that have been widely test in New Jersey, and, in those tests, lead levels were found to be very low or undetectable, Barnes said.

The EPA, which has been investigating the fields in New Jersey, is expected to release its findings sometime in the next week. Barnes said the city will review those guidelines and recommendations, before it proceeds with the removal of the artificial turf playing surface.

Director of Health, Dr. Johnnie Lee, in a letter to Starr, stated that lead exposure is primarily a concern for children under the age of seven, and that the health effects of exposure to fields like the one at Boyle Stadium are unknown.