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Issued: 18/09/2014 11:14:00

Pollution Band: Moderate


Widespread moderate particle pollution has been measured across London and south east England since Tuesday 16th September. This moderate air pollution was caused by a combination of imported air pollution from the Netherlands, Belgium and Germany and emissions from London itself. Widespread moderate particle pollution will to continue on Friday. Later in the day the winds will become southerly, bringing pollution from France.

Although incoming air will bring precursors for ozone generation it is still expected to remain in the upper end of the 'low' banding being limited by overcast conditions in the morning and the shortening day.

Calm conditions may also allow the build up of nitrogen dioxide at busy roadside locations, reaching 'moderate' in places.

Air pollution is expected to remain ‘low’ throughout the forecast period for the following pollutants:

Sulphur dioxide

This forecast is intended to provide information on expected pollution levels in areas of significant public exposure. It may not apply in very specific locations close to unusually strong or short-lived local sources of pollution.


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Issued: Not issued

Start: Not issued

Finish: Not issued

Pollution Band: Not issued


The forecast for tomorrow is not available yet but should be issued around midday.

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. 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 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.

* Daily Air Quality Index information sourced from UK-AIR (Air Information Resource) website.

* 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.