The eight major air pollutants which are generally factored for Air Quality Index (AQI) are:
- Particulate Matter (PM10)
- Particulate Matter (PM2.5)
- Nitrogen Dioxide (NO2)
- Sulphur Dioxide (SO2)
- Carbon Monoxide (CO)
- Ozone (O3)
- Ammonia (NH3)
- Lead (Pb)
The table above
shows the advisory from Ministry of Health & Family Welfare. The air quality index (AQI) data of 245 Indian cities is collected by Central Pollution Control Board (CPCB), Indian Ministry of Environment Forests and Climate Change on real
time basis. 0ut of 245 cities, the cities which are in very poor category and which are associated with respiratory illness on prolonged exposure to polluted air and pronounced respiratory or other illnesses in vulnerable population on short exposure. These cities are: Bhubaneswar, Bulandshahr, Byasanagar, Byrnihat, Chhapra, Chittoor, Churu, Cuttack, Delhi, Dholpur, Faridabad, Katihar, Keonjhar, Kota, Kurukshetra, Manesar, Meerut, NOIDA, Panipat, Patna, Purunia, Rairangpur, Rajgir, Rohtak, Saharsa, Samastipur, Siwan, Sriganganagar, Talchar, Ulhasnagar, Visakhapatnam, Arrah, Angul, Bettiah, Bhagalpur, Bharatpur, Bhiwadi, Baripada, Bathinda, Begusarai, Baghpat, Balasore, Ballabgarh, Dharuhera, Fatehabad, Ghaziabad, Greater Noida, Gurugram, Hanumangarh, Hisar, Jhunjhunu, Jind and Kaithal.
The vulnerable population is at high risk. These include elderly, children under 5 years, pregnant women, pre-existing illnesses like asthma and other airway or lung (respiratory) and heart (cardiovascular) diseases.
AQI 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. An AQI value of 50 or below represents good air quality, while an AQI value over 300 represents hazardous air quality.
For each pollutant an AQI value of 100 generally corresponds to an ambient air concentration that equals the level of the short-term national ambient air quality standard for protection of public health. AQI values at or below 100 are generally thought of as satisfactory. When AQI values are above 100, air quality is unhealthy: at first for certain sensitive groups of people, then for everyone as AQI values get higher.
The AQI is divided into six categories. Each category corresponds to a different level of health concern. Each category also has a specific color. The color makes it easy for people to quickly determine whether air quality is reaching unhealthy levels in their communities.
According to USA's Environment Protection Agency, AQI of 0 to 50 level is moderate and it shows that air quality is satisfactory, and air pollution poses little or no risk. AQI of 101 to 150 is unhealthy for sensitive groups. The members of sensitive groups may experience health effects. The general public is less likely to be affected.AQI of 151 to 200 is unhealthy. Some members of the general public may experience health effects. The members of sensitive groups may experience more serious health effects. The AQI of 201 to 300 level is very unhealthy. It is a cause of health alert. The risk of health effects is increased for everyone. The AQI of 301 and higher level is hazardous. It is cause for health warning of emergency conditions. Everyone is more likely to be affected.