What if you exposed humans to 300 parts per billion of ozone, while exercising or under heat stress, and nothing happened to them?
In the first study, 23 adults were exposed to 300 parts per billion (ppb) ozone while exercising for two hours.
Here’s what happened to them:
In the next study, 16 adults were exposed to 300 ppb ozone at 90.5 degrees Fahrenheit for two hours.
Here’s what happened:
Back to our original question, if you were EPA then you would propose to tighten the ozone standard from 75 ppb down to 65 ppb.
Makes perfect sense.