It's not very nice. The poor kids are scared. And it's not just children with respiratory problems who are affected. Joggers, outdoor workers and older people also feel the effects.
Ozone is a caustic substance that is the prime ingredient in smog.
In the stratosphere, it occurs naturally and forms a protective layer that shields Earth from ultraviolet radiation. But on the ground, even at low levels, it is harmful. Tissues redden and swell. Cellular fluid seeps into the lungs and over time their elasticity drops. Macrophage cells rush to the lung's defense, but they too are stunned by the ozone.