Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Map of Philadelphia displaying the interpolated Pb-in-soil contents grouped by land use. Areas with Pb ≥ 400 mg/kg are color-coded for their corresponding land use (industrial, parks, residential, culture/recreation, and commercial). Grey areas with Pb ≥ 400 mg/kg correspond to a type of land use not included in this study.
