They are talking about the ozone levels. wow.
They're measuring ozone levels. Ozone is a bluish gas that lives mainly above us. It's atom is called O3, and it causes lung irratation and possible permanent damage. BTW-its created naturally when the air in our atmosphere absorbs ultraviolet light form the sun. That's is O3's good side. Its bad side is it sticks to just about anything.
People have ozone (electrostatic) generators in their houses to absorb cigarette smoke. What they don't know is that the same ozone thats mixes with the smoke in the air, absorbing it, and making it fall to the ground, is mixing with the airsacs in our lungs, and absorbing them too! This is not a good thing.
hmmm....me, I was concerned about the particulate matter. That's the stuff that's making me sneeze little dirt balls.