Figure 1.
(a) Location of the Beijing City in China; and (b) the 62 sampling sites for settled dust in the Beijing urban area.
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.