Lisa Bloodgood (R), a Brooklyn-based environmental advocate and former city council staffer, Franziska Landes, a Columbia University Environmental Sciences graduate student, and Sabina Gilioli (L), a Barnard College research assistant, help Reuters identify lead in backyards and public spaces in Brooklyn in New York City, U.S. September 14, 2017. The soil on a jogging path in McCarren Park in Williamsburg, Brooklyn revealed lead levels above a federal safety threshold. Picture taken September 14, 2017. To match Special Report USA-LEAD/NEW YORK REUTERS/Michael Pell