New York, NY —

The New York City Parks department has closed Harlem's Thomas Jefferson Park due to elevated levels of lead.

REPORTER: Al Huang, an environmental justice attorney for the Natural Resources Defense Council, says the contaminated park poses a danger to the entire city.

HUANG: Not only is there now a concern that the lead will be available for people to be exposed to playing on these fields - I think the city did the right thing by shutting it down - but also that water run off, currently there is no policy that contains storm water runoff from these fields will just make there ways to the waterways caring lead, arsenic and the other potential toxins on the field.

REPORTER: Huang says heat is also a major issue, because the turf can get hotter than asphalt in the summer. Public Advocate Betsy Gotbaum says she's pushed for testing for two years.

A spokesperson for the Parks Department says Jefferson was the only park with artificial turf that tested positive for lead. So far, the department has tested 16 parks out of the 98 that use the artificial turf.