Figure 1.
Location of all cohorts. Circles mark the cohort areas in which both particulate matter (PM) and nitrogen oxides were measured. Squares indicate cohort areas where only NO2 and nitrogen oxides (NOx) were measured.
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.