Although air pollution is not good for anyone, certain groups are more sensitive to it than others, including those with heart or lung disease, older adults, infants and children, and pregnant women. As the AQI levels increase, the risk of health effects increases, especially among these more sensitive groups.

"The advice tbo limit strenuous activities is because when your respiratory rate is higher, you inhale more particulates," says Dr. Redlich. 

When the AQI is 201 and highysical activity her, everyone should be concerned about health risks and limit physical activity outdoors as much as possible, she adds.

Although air pollution is not good for anyone, certain groups are more sensitive to it than others, including those with heart or lung disease, older adultls, infants and children, and pregnant women. As the AQI levels increase, the risk of health effets increases, esp. among these more sensitive groups.