Request ID: FOI-1871-2324 Date published: 25 September 2023
You asked
Would TfL please submit details of all air quality recordings and air safety checks that are carried out on the London underground network. Could it please make public how often readings are taken that measure over the safety threshold on the Air Quality Index.
We answered
Our ref: FOI-1871-2324/GH Thank you for your request received by Transport for London (TfL) on 30 August 2023 asking for information about air quality on the London Underground. Your request has been considered under the requirements of the Environmental Information Regulations and our information access policy. I can confirm that we do hold the information you require. The below reports found on TfL webpage, will provide the detailed reports on the measurements conducted by 4rail services. The 2023 measurements are currently being carried out, and the full report is to be published in Autumn 2023. https://tfl.gov.uk/corporate/publications-and-reports/environment-reports December 2018 - https://content.tfl.gov.uk/simulated-passenger-journeys-2019.pdf April 2019 - https://content.tfl.gov.uk/dust-monitoring-april-2019.pdf February 2020 - https://content.tfl.gov.uk/dust-monitoring-february-2020.pdf October 2021 - https://content.tfl.gov.uk/train-operator-dust-monitoring.pdf https://content.tfl.gov.uk/dust-monitoring-lu-stations.pdf Please note that TfL apply respirable dust limits for PM4.3 which are set by the Health and Safety Executive. The UK legal ambient limits for PM2.5, or the WHO recommended limits, are not appropriate for enclosed environments such as the London Underground network. This is because these limits for ambient air quality only apply to outdoor areas and are representative of typical population exposure to outdoor air quality concerns such as traffic exhaust fumes. The health evidence beyond ambient air quality limits is based on studies in these environments. Particulate matter levels are higher on the Underground than on the surface because they are being generated in a more contained area however levels of the other substances which contribute to pollution and, which are arguably more harmful, are lower. PM levels on the Underground are below HSE recommendations and in general are fully complaint with the recommendations of the Institute of Occupational Medicine on respirable dust exposures which are set at ¼ of the regulatory limit. Hence there is currently insufficient health evidence to suggest the UK ambient air or WHO limits are appropriate on the Tube network, given that composition of material is different, and customers are only exposed to the dust for relatively short periods of time during their journeys, or for a few hours at time in relation to staff working patterns. The Government’s Committee on the Medical Effects of Air Pollutants (COMEAP) reviewed the evidence on the health effects of particulate matter in the Tube at TfL’s request. COMEAP advised in 2018 that there is currently insufficient evidence to determine the health impact of underground particulate matter and that further research is needed. We have commissioned academic studies to better understand the potential health impacts of Tube dust. While these are undertaken, our monitoring focuses on ensuring we comply with the HSE and IOM legal requirements (based on 8-hour average dust levels). TfL employs the service of 4rail services to carry out network wide occupational exposure monitoring which consists of static and personal monitoring on 24 stations spread across the network and on within the trains of all tube lines. If this is not the information you are looking for, or if you are unable to access it for some reason, please do not hesitate to contact me. If you are not satisfied with this response please see the attached information sheet for details of your right to appeal. Yours sincerely Graham Hurt FOI Case Officer FOI Case Management Team General Counsel Transport for London
