Figure 4.
Photographs of air-elimination ducts (upper left); air-injection motor and filter (upper right); main ward with natural ventilation (lower left); respiratory isolation room (lower right).
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.