Figure 3.
Box plots of far-field (FF), outdoor, and near-field (NF) background particle number concentration (PNC) measured by condensation particle counter (CPC) (#/cm3).
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.