Question

What two things are necessary to prove an exposure occurred

Answer 1

An outbreak located at the site of exposure and physical evidence of the exposure it self maybe idk

Answer 2

The two things are:

- Personal testimony of a licensed health investigators

- Objective proof that taken from the site

The personal testimony could include things such as investigators smell something unusual from the site or notice that there is change in color on the land in the site. The objective proof could include things such as chemical residual taken from the substance or broken container that cause a chemical leakage on the site.