Let’s say you open up a lab report you’ve received, one containing the analysis of a sample of your drinking water, or a sample of the indoor air where you work. You navigate the maze of acronyms and unfamiliar words to find some numbers. Now… what the heck do they mean? The only thing you’re interested in is whether those numbers represent a threat to your health.
To make that judgment, we rely on the health standards determined by government agencies—in the US, it’s usually the Environmental Protection Agency. (States set their own standards, but they largely reflect the EPA’s numbers.) Below those standards, exposure is presumed to be acceptable and safe.
The EPA was created in 1970 to deal with the glaringly obvious pollution that spurred the passage of the Clean Air Act and Clean Water Act. The agency brought health research to bear on that pollution, setting safe limits and ensuring that air and water were cleaned up when these weren’t met. It also limited what a facility was allowed to release into the environment for the first time.