Monitoring of Pollution levels on the London Underground
Request ID: FOI-3290-2223 Date published: 31 March 2023
You asked
Follow-up to FOI-3043-2223: Hello and thank you for your reply,
I have already looked at reports that are already in the public domain which only relate to particle matter of various sizes & dust composition, the pollution data I would like information on would relate to gases that may be present i.e. methane, hydrogen sulphide, carbon monoxide, nitrogen etc.
We answered
TfL Ref: FOI-3290-2223 Thank you for your further request received by Transport for London (TfL) on 7th March 2023 asking for information about gases on the London Underground. Your request has been considered in accordance with the requirements of the Freedom of Information Act and our information access policy. Specifically you asked, further to case reference FOI-3043-2223: “I have already looked at reports that are already in the public domain which only relate to particle matter of various sizes & dust composition, the pollution data I would like information on would relate to gases that may be present i.e. methane, hydrogen sulphide, carbon monoxide, nitrogen etc.” TfL does not routinely measure gases in the London Underground network. The London Underground is an electrified system which does not generate gases by its operation. The only gas significantly above ambient levels is Carbon Dioxide which is from passengers using the network. On occasions gases are monitored in connection with specific engineering works where generators are being operated in tunnels outside of operating hours. Nitrogen Dioxide and Carbon Monoxide are monitored to ensure levels do not exceed regulatory exposure limits. The levels measured would not reflect normal operating conditions. If this is not the information you are looking forplease do not hesitate to contact me. Please see the attached information sheet for details of your right to appeal as well as information on copyright and what to do if you would like to re-use any of the information we have disclosed. Yours sincerely, David Wells FOI Case Officer FOI Case Management Team General Counsel Transport for London
