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 on the Additional information page. 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 forecast.
Step 3: Use the health messages corresponding to the highest forecast level of pollution as a guide.
Air pollution bands and indices µ/m³
| Pollutants | Band | Low | Moderate | High | Very High | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Index | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | |
| Ozone - running 8 hourly mean | µg/m³ | 0-33 | 34-66 | 67-100 | 101-120 | 121-140 | 141-160 | 161-187 | 188-213 | 214-240 | 241 or more |
| Nitrogen Dioxide - hourly mean | µg/m³ | 0-67 | 68-134 | 135-200 | 201-267 | 268-334 | 335-400 | 401-467 | 468-534 | 535-600 | 601 or more |
| Sulphur Dioxide - 15-minute mean | µg/m³ | 0-88 | 89-177 | 178-266 | 267-354 | 355-443 | 444-532 | 533-710 | 711-887 | 888-1064 | 1065 or more |
| PM2.5 Particles - 24 hour running mean | µg/m³ | 0-11 | 12-23 | 24-35 | 36-41 | 42-47 | 48-53 | 54-58 | 59-64 | 65-70 | 71 or more |
| PM10 Particles - 24 hour running mean | µg/m³ | 0-16 | 17-33 | 34-50 | 51-58 | 59-66 | 67-75 | 76-83 | 84-91 | 92-100 | 101 or more |
A health descriptor is associated with each band based upon current understanding and research studies (Department of Health). Current descriptors are presented below.
| Air Pollution Banding | Value | Accompanying health messages for at-risk groups and the general population | |
|---|---|---|---|
| At-risk individuals* | 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 Additional Information on the Short-term Effects of Air Pollution page.