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PureTools

Air Quality Index

Real-time global pollution map & health impact.

Use the search bar above to check air quality for any city.

Breathing Easy: A Guide to Air Quality

The Air Quality Index (AQI) is a standardized system used to communicate how polluted the air is. Think of it as a yardstick that runs from 0 to 500. The higher the AQI value, the greater the level of air pollution and the greater the health concern.

Decoding the AQI Scale

  • 0 - 50 (Good): Air quality is satisfactory, and air pollution poses little or no risk.
  • 51 - 100 (Moderate): Acceptable for most, but sensitive people (asthma) should watch out.
  • 101 - 150 (Unhealthy for Sensitive): Children, the elderly, and those with lung disease are at risk.
  • 150+ (Unhealthy/Hazardous): Everyone may begin to experience health effects. Avoid outdoor exertion.

The Cigarette Analogy

This dashboard uses a rule of thumb popularized by researchers at Berkeley Earth to visualize the danger of PM2.5 (fine particulate matter). They estimate that breathing air with a PM2.5 concentration of 22 µg/m³ for 24 hours is roughly equivalent to the health damage caused by smoking one cigarette.

Note: This is a rough equivalence for communication purposes, meant to highlight the long-term cardiovascular risks of pollution.

Frequently Asked Questions

What is PM2.5 and why is it dangerous?

PM2.5 refers to particles smaller than 2.5 micrometers—about 3% the diameter of a human hair. Because they are so small, they can bypass your nose's filtration, travel deep into your lungs, and even enter your bloodstream, causing heart and lung disease.

Should I exercise outside when AQI is high?

Generally, no. When you exercise, you breathe deeper and faster, inhaling more pollutants. If the AQI is above 100 (Orange), consider moving your workout indoors or finding a park away from busy roads.