Daily Air Quality Index

Index and Bands

In the UK most air pollution information services use the index and banding system approved by the Committee on Medical Effects of Air Pollution Episodes (COMEAP). The system uses 1-10 index divided into four bands to provide more detail about air pollution levels in a simple way, similar to the sun index or pollen index.

1-3 (Low)
4-6 (Moderate)
7-9 (High)
10 (Very High)

The overall air pollution index for a site or region is calculated from the highest concentration of five pollutants:

Nitrogen Dioxide
Sulphur Dioxide
Ozone
Particles PM_2.5
Particles PM₁₀

Air Pollution Forecasts

Air Pollution Forecasts are issued on a regional basis for three different area types:

In towns and cities near busy roads
Elsewhere in towns and cities
In rural areas

Forecasts are based on the prediction of air pollution index for the worst-case of the five pollutants listed above, for each region.

How to use the Daily Air Quality Index

Step 1

Determine whether you (or your children) are likely to be at risk from air pollution. Information on groups who may be affected is provided in the Health Impacts and Advice section. Your doctor may also be able to give you advice.

Step 2

If you may be at-risk, and are planning strenuous activity outdoors, check the air pollution regional forecast on the KentAir Home page.

Step 3:

Use the health messages corresponding to the highest forecast level of pollution as a guide.

Air Pollution Banding	Value	Accompanying health messages for at-risk individuals*	Accompanying health messages for the general population
Low	1-3	Enjoy your usual outdoor activities.	Enjoy your usual outdoor activities.
Moderate	4-6	Adults and children with lung problems, and adults with heart problems, who experience symptoms, should consider reducing strenuous physical activity, particularly outdoors.	Enjoy your usual outdoor activities.
High	7-9	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.	Anyone experiencing discomfort such as sore eyes, cough or sore throat should consider reducing activity, particularly outdoors.
Very High	10	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.	Reduce physical exertion, particularly outdoors, especially if you experience symptoms such as cough or sore throat.

* 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 on the Defra UK-AIR website.

Boundaries Between Index Points for Each Pollutant:

Ozone

Based on the running 8-hourly mean.

Index	1	2	3	4	5	6	7	8	9	10
Band	Low	Low	Low	Moderate	Moderate	Moderate	High	High	High	Very High
µgm^-3	0-33	34-66	67-100	101-120	121-140	141-160	161-187	188-213	214-240	241 or more

Nitrogen Dioxide

Based on the hourly mean concentration.

Index	1	2	3	4	5	6	7	8	9	10
Band	Low	Low	Low	Moderate	Moderate	Moderate	High	High	High	Very High
µgm^-3	0-67	68-134	135-200	201-267	268-334	335-400	401-467	468-534	535-600	601 or more

Sulphur Dioxide

Based on the 15-minute mean concentration.

Index	1	2	3	4	5	6	7	8	9	10
Band	Low	Low	Low	Moderate	Moderate	Moderate	High	High	High	Very High
µgm^-3	0-88	89-177	178-266	267-354	355-443	444-532	533-710	722-887	888-1064	1065 or more

PM_2.5 Particulate Matter

Based on the daily mean concentration for historical data, latest 24 hour running mean for the current day.

Index	1	2	3	4	5	6	7	8	9	10
Band	Low	Low	Low	Moderate	Moderate	Moderate	High	High	High	Very High
µgm^-3	0-11	12-23	24-35	36-41	42-47	48-53	54-58	59-64	65-70	71 or more

PM₁₀ Particulate Matter