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.
US Geological Survey scientist at the Eastern Ecological Science Center preparing to analyze samples on a high resolution mass spectrometer for per- and polyfluorinated alkyl substances (PFAS).
Public Domain.
