Particle Pollution Air Quality Air Quality Index Health Advisory Good 0 - 50 Air quality is good. Enjoy activities. Moderate 51 - 100 People who are unusually sensitive to air pollution should consider reducing prolonged or heavy exertion. Unhealthy for Sensitive Groups 101 - 150 People with heart or lung disease (including asthma), older adults and children should cut back or reschedule strenuous activities. Unhealthy 151 - 200 Everyone, especially people with heart or lung disease (including asthma), older adults and children should cut back or reschedule strenuous activities. Sensitive groups should avoid strenuous activities. Very Unhealthy 201 - 300 Everyone, especially people with heart or lung disease (including asthma), older adults and children should significantly cut back on physical activities. Sensitive groups should avoid all physical activities.