What was the effect of the 2010 Icelandic volcano ash cloud on air quality in the UK?

Where can I find old reports and guidance published by Defra?

How effective are air quality regulations?

Where can I find more information about Smoke Control Zones?

What are the limits for emissions of pollutants into the atmosphere?

How does the UK determine the number of sites required for monitoring? Is there a map or list available?

Which part of the United Kingdom has the best air quality?

What defines a pollution episode and when was the first official episode?

How can refineries reduce their emissions?