Copied from DEFRA Website:
Issued at 23/01/2017 11am
Many places across the UK are experiencing High and Very High levels of air pollution due to the continuing high pressure and associated light winds. High and Very High levels are expected to continue throughout today across England, South Wales and Northern Ireland. In Scotland, levels are expected to remain Low.
Many places across England and Wales will continue to experience High air pollution levels due to the continuing light winds. Very High levels are possible again, mainly across southeast, central and eastern England. Pollution levels in Northern Ireland will remain elevated but will reduce through the day as winds increase. In Scotland pollution levels will remain Low.
Light winds and foggy conditions are expected to continue through Wednesday, especially across southern and eastern parts of England. This will lead to the ongoing risk of areas of Moderate air pollution levels, along with some High levels. Meanwhile, across the north and west, increasing winds should lead to air pollution returning to Low levels. These Low levels should spread to all parts during Thursday and Friday.
Please see the DEFRA Website for further information, and also where you can enter your post code to find out the level in your area.