Question to the Department for Environment, Food and Rural Affairs:

To ask the Secretary of State for Environment, Food and Rural Affairs, for what reason data on particulate matter, PM2.5 and PM10, from the Automatic Urban and Rural Network was not available on his Department's UK-Air website for the Marylebone Road monitoring station during the days up to and including an air pollution episode that peaked on Friday 14 January 2022; and if he will publish details of any other areas with which there were issues with monitoring.

The data issues at Marylebone Road during the pollution episode that peaked on Friday 14 January were caused by the replacement of older equipment where a data communication error occurred that was not immediately identified. This error was preventing data flowing from the new instruments onto UK-air. This error was identified on 17 January and remedied on the same day. Data for PM2.5 and PM10 at the site can be viewed at: Data Selector Tool - Defra, UK

UK-Air has been improved within the last 12 months to show data communications from Environment Agency managed contractors. This data now shows ‘live site code’ where live reasons for downtime are now available on the interactive map:

Interactive monitoring networks map - Defra, UK