Answer:
In high-pressure areas. 
Explanation:
Columbus clouds form and get pushed upwards causing pressure. 
 
        
             
        
        
        
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The ground-level ozone is a harmful air pollutant that can be a danger to one's health. It is commonly created by chemical between oxides and nitrogen. Similar to ground-level ozone, smog can also be a danger to one's health, especially to the lungs. It is a mixed smoke and fog.