Mumbai’s air quality level ‘unhealthy’: Report

Mumbai’s dipping air quality levels are a cause for concern. Pic/Getty Images

Air Quality Index (AQI) is a yardstick to measure the quality of air in a given area. It is measured from 0 to 500. A higher value of AQI denotes a greater level of pollutants in the air and hence a more severe impact on health.

The AQI index is divided into six categories, each corresponding to a different level of health concern.

- Green (0-50) - Good

- Yellow (51-100) - Moderate

- Orange (1001-150) - Unhealthy for sensitive groups

- Red (151-200) - Unhealthy

- Purple (201-300) - Very unhealthy

- Maroon (301 and higher) - Hazardous

According to Swiss organisation IQAir, with AQI 157, Mumbai's air quality level is under the "unhealthy" category today.

The report also stated that PM2.5 concentration in Mumbai air is currently 13.5 times above the WHO annual air quality guideline value.

Fine particulate matter (PM2.5) is an air pollutant that is a concern for people's health when levels in air are high. PM2.5 are tiny particles in the air that reduce visibility and cause the air to appear hazy when levels are elevated. Outdoor PM2.5 levels are most likely to be elevated on days with little or no wind or air mixing.