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.
Predicted concentrations of NO2 based on proximity to a freeway (FWY) or non-freeway (NFWY) major road. Vertical bars indicate the upper bound of the 95% confidence limit for each prediction. Results are shown for two types of communities: (a) within the LA basin with overall mean NO2 level 25.3 p.p.b. and (b) outside the LA basin with overall mean 9.5 p.p.b.
