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.
The short horizontal dashed line indicates the safe level of bacterial reduction (>5-log10). a-c Values with different letters are significantly different (P < 0.05).
