Question to the Department for Transport:

To ask the Secretary of State for Transport, what recent assessment she has made of the air quality on the rail network; and whether her Department plans to issue updated guidance on air quality on the rail network.

The Department is funding monitoring and research to assess air quality in stations and onboard trains through the Rail Safety and Standards Board (RSSB). This includes the £5.5 million Air Quality Monitoring Network, which is collecting data at up to 72 stations across Great Britain. Where issues are identified, Network Rail and train operators are required to implement Air Quality Improvement Plans.

RSSB has also undertaken two studies to assess air quality onboard trains, with further testing planned in 2026 on different rolling stock types, including newer bi-mode, tri-mode and electric trains.

The Department keeps its air quality policy and the guidance it provides to industry under review as further evidence becomes available and continues to consider whether any updates are needed.