Provenance
Photo by Gwen Bausmith, U.S. EPA

Reuse
A United States government work prepared by an officer or employee of the United States government as part of that person's official duties.
It is not subject to copyright in the United States and there are no copyright restrictions on reproduction, derivative works, distribution, performance, or display of the work. Anyone may, without restriction under U.S. copyright laws:
• reproduce the work in print or digital form;
• create derivative works;
• perform the work publicly;
• display the work;
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