The U.S. Consumer Product Safety Commission (CPSC), in a report issued two years ago, said synthetic turfs do not release enough lead to harm children who play on them.

The issue has raised concern among some health and safety advocates because of the use of recycled tires for “crumbs” that create the turf’s base. It’s relevant on Vashon, where voters are currently considering a $3.5 million bond measure that would, among other things, cover the costs of a new synthetic turf field at Vashon High School.

Bob Hennessey, a school board member, called attention to the safety commission’s report, noting that it offers up evidence that government scientists have found the substance safe. “And that’s good enough for me,” he said.

Even so, according to USA Today, two of the country’s largest cities — New York and Los Angeles — have decided they won’t use synthetic turf that contains crumb rubber. The two cities are instead purchasing synthetic fields that use a different material — such as coated grains of sand — as its base.

The CPSC evaluation, one of the most extensive looks at this issue, showed that newer fields had no lead or generally had the lowest lead levels. Although small amounts of lead were detected on the surface of some older fields, none of these tested fields released amounts of lead that would be harmful to children, according to the commission.