Daily Air Quality Index (DAQI)
Due to the current coronavirus (COVID-19) pandemic please follow the Government's stay at home guidance. More information on this guidance can be found here: https://www.gov.scot/coronavirus-covid-19/. During those periods of essential activity outdoors the advice below should also be followed.
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 PM2.5
- Particles < 10µm (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 Additional information on the short-term effects of air pollution section below. 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 Forecasts 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
The tables below show the bandings 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 |
PM2.5 Particles
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 Particles
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 | 0-16 | 17-33 | 34-50 | 51-58 | 59-66 | 67-75 | 76-83 | 84-91 | 91-100 | 101 or more |
Additional Information on the Short-Term Effects of Air Pollution
The air quality index (DAQI) has been developed to provide advice on expected levels of air pollution. In addition, information on the short-term effects on health that might be expected to occur at the different bands of the index (Low, Moderate, High, Very High) is provided. It is possible that very sensitive individuals may experience health effects even on Low air pollution days. This advice applies to anyone experiencing symptoms.
Short-term effects of air pollution on health
Air pollution has a range of effects on health. However, air pollution in the UK does not rise to levels at which people need to make major changes to their habits to avoid exposure; nobody need fear going outdoors.
- Adults and Children with lung or heart conditions - It is known that, when levels of air pollutants rise, adults suffering from heart conditions, and adults and children with lung conditions, are at increased risk of becoming ill and needing treatment. Only a minority of those who suffer from these conditions are likely to be affected and it is not possible to predict in advance who will be affected. Some people are aware that air pollution affects their health: adults and children with asthma may notice that they need to increase their use of inhaled reliever medication on days when levels of air pollution are higher than average.
- Older people are more likely to suffer from heart and lung conditions than young people and so it makes good sense for them to be aware of current air pollution conditions.
- The general population - At Very High levels of air pollution, some people may experience a sore or dry throat, sore eyes or, in some cases, a tickly cough even in healthy individuals.
- Children need not be kept from school or prevented from taking part in games. Children with asthma may notice that they need to increase their use of reliever medication on days when levels of air pollution are higher than average.
Action that can be taken
When levels of air pollution increase it would be sensible for those who have noticed that they are affected to limit their exposure to air pollutants. This does not mean staying indoors, but reducing levels of exercise outdoors would be reasonable.
- Older people and those with heart and lung conditions might avoid exertion on High pollution days.
- Adults and children with asthma should check that they are taking their medication as advised by their health practitioner and may notice that they need to increase their use of inhaled reliever medication.
- Adults with heart and circulatory conditions should not modify their treatment schedules on the basis of advice provided by the air quality index: such modification should only be made on a health practitioner's advice.
- Some athletes, even if they are not asthmatic, may notice that they find their performance less good than expected when levels of a certain air pollutant (ground level ozone) are High, and they may notice that they find deep breathing causes some discomfort in the chest: This might be expected in summer on days when ground level ozone levels are raised. This does not mean that they are in danger but it would be sensible for them to limit their activities on such days.
