What is Air Quality?
Clean air contains only small amounts of particulate matter and chemical pollutants. Poor air quality with high levels of pollution is often foggy and hazardous to health and the environment.
What are the dangers of air pollution?
Air pollution consists of chemicals or particles in the air that can harm the health of humans, animals, and plants. The service provides Air Quality data on major pollutant gases like Carbon monoxide (CO), Ozone (O3), Nitrogen dioxide (NO2), Sulphur dioxide (SO2), PM 2.5 and PM 10.
How is air quality determined?
The Air Quality Index used by all the world's environmental authorities to inform the public about the level of air pollution as well as to predict air pollution. Different countries have their own air quality index according to national standards. Service provides data according to US EPA Data Standards and UK Defra. A description of each of the air quality indices see below.
See the air quality for most frequently requested cities:
US - EPA standard
The Air Quality Index is divided into six categories. Each category corresponds to a different level of health concern. Each category also has a specific color. Color allows people to quickly tell if air quality is reaching unhealthy levels.
|Daily Color||Levels of Concern||Values of Index||Description of Air Quality|
|Green||Good||0 to 50||Air quality is satisfactory, and air pollution poses little or no risk.|
|Yellow||Moderate||51 to 100||Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution.|
|Orange||Unhealthy for Sensitive Groups||101 to 150||Members of sensitive groups may experience health effects. The general public is less likely to be affected.|
|Red||Unhealthy||151 to 200||Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects.|
|Purple||Very Unhealthy||201 to 300||Health alert: The risk of health effects is increased for everyone.|
|Maroon||Hazardous||301 and higher||Health warning of emergency conditions: everyone is more likely to be affected.|
|US - EPA standard|
UK Defra Index
The index is numbered from 1 to 10 and divided into four ranges, from low (1) to very high (10), to provide detailed information about air pollution levels in a simple form, similar to the solar index.
|Index value||Air Pollution Banding||Accompanying health messages for at-risk individuals*||µgm-3|
|1-3||Low||Enjoy your usual outdoor activities.||0-35|
|4-6||Moderate||Adults and children with lung problems, and adults with heart problems, who experience symptoms, should consider reducing strenuous physical activity, particularly outdoors.||36-53|
|7-9||High||Adults and children with lung problems, and adults with heart problems, should reduce strenuous physical exertion, particularly outdoors, and particularly if they experience symptoms. People with asthma may find they need to use their reliever inhaler more often. Older people should also reduce physical exertion.||54-70|
|10||Very High||Adults and children with lung problems, adults with heart problems, and older people, should avoid strenuous physical activity. People with asthma may find they need to use their reliever inhaler more often.||71 or more|
|*Adults and children with heart or lung problems are at greater risk of symptoms. Follow your doctor's usual advice about exercising and managing your condition. It is possible that very sensitive individuals may experience health effects even on Low air pollution days. Anyone experiencing symptoms should follow the guidance provided below.|