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‘Hazardous’ Air-Quality Index Level

All About the “Hazardous” Air-quality Index Level

  • We classify conditions as moderate if

    • Short-term (one-hour) concentrations are > 526 µg/m3
    • Eight-hour average concentrations are > 300 µg/m3
    • 24-hour average concentrations are > 250–500 µg/m3
  • The AQI for hazardous air quality is 301 and above

  • The visibility during hazardous air quality is usually < 1 mile

  • Health effects expected

    • Serious aggravation of heart or lung disease
    • Serious risk of respiratory effects in general population
  • Caution statements?

    • General population should avoid any outdoor activity
  • Protective actions?

    • If symptomatic, evacuate to cleaner air shelter or leave area, if safe to do so
Last modified on April 21st, 2017
Posted on April 21st, 2017