Request ID: FOI-1001-2324 Date published: 07 August 2023
You asked
1. Any monitoring of dust / pollution levels on the underground and any health impact assessment (e.g. assessment against WHO/ HSE guidelines), and any comparison against pollution levels in zone 1 (e.g. Oxford Circus underground vs overground PM2.5 levels)
2. Any plan for reducing particulate pollution on the underground lines
3. Any health assessment and monitoring for noise levels on the underground (e.g. on the Victoria line or other deep lines). Do the noise levels on the underground breach safety
4. Any plans to reduce noise pollution on the underground
5. Any health impacts of the policy of keeping windows open on buses? For example, by recommending keeping windows open are you exposing passengers to more of London's toxic air - and is this reflected in your risk register(s)?
6. Finally, any health risk registers for passengers TfL may keep
I'd like the most recent health/ risk assessment and levels maybe over the past year
We answered
TfL Ref: FOI-1001-2324 Thank you for your request which we received on 12 July 2023, asking for information about noise and pollution on the London Underground. Your request has been considered in accordance with the requirements of the Environmental Information Regulations and our information access policy. I can confirm that we hold the information you require. You asked for:
Any monitoring of dust / pollution levels on the underground and any health impact assessment (e.g. assessment against WHO/ HSE guidelines), and any comparison against pollution levels in zone 1 (e.g. Oxford Circus underground vs overground PM2.5 levels)
TfL undertakes regular independent occupational exposure measurements of the dust levels on the London Underground. The measurements are taken in ticket halls and platforms of 24 stations with in deep tube sections and some on the subsurface lines, and inside train operator cabs for all lines. This is to measure ourselves against the Health and Safety Executive’s (HSE) occupational exposure limits for dust. The upcoming report and previous reports can be found on the following link: - https://tfl.gov.uk/corporate/publications-and-reports/environment-reports Our measurements show that we are consistently well below the HSE occupational exposure limits for dust, and on most of the network are below the more stringent levels set by the Institute of Occupational Medicine. The levels of dust and pollution above and below ground are not comparable as they are made up of different substances. Surface pollutants, particularly traffic source emissions have a completely different toxicological profile to tube dust pollutants so it’s a complex comparison process. Below ground dust is predominantly iron oxide particles. Whilst we know that pollution above ground can have negative health impact, there is no evidence of this on the underground. However, TfL have commissioned Imperial College to undertake two studies to ascertain if there are health impacts as a result of exposure to tube dust.
Any plan for reducing particulate pollution on the underground lines
TfL has an ongoing cleaning regime to clean the surfaces of the tunnel section. This methodology has seen an improvement of the dust levels between 2020 and 2021 by 19 per cent when measured from the platform and 37 per cent when measured from the driver’s cab. In addition to cleaning the tunnels in this way, we are also exploring the market to find suitable technologies that we can deploy and trial on the network. We also increasingly use battery-operated tools, rather than diesel generators, for works on Underground lines. This contributes to a reduction in particulate matter on the network.
Any health assessment and monitoring for noise levels on the underground (e.g. on the Victoria line or other deep lines). Do the noise levels on the underground breach safety
We recognise that the noise on some parts of TfL’s services can be high and uncomfortable at times. We measure the volume of noise, and the duration of this noise, across all the London Underground lines. For the majority of our customers, exposure to very high levels of noise on our services is usually for short periods of time. While there are no national standards for public exposure to noise, there are legally set levels of noise for employees. We monitor the health risks relating to noise exposure for our colleagues who spend most time travelling on the network, e.g. train operators. This information, which confirms that train operators’ exposure to noise while driving trains during their shifts is within the legal requirements set by the Health & Safety Executive, gives us confidence that it is unlikely that our customers – who have much lower exposure to noise – are at significant health risks/loss of hearing risk as a result of the noise on our network. However, we recognise that it can be uncomfortable at times, and we have set out some of the action we are taking below. We are also considering, given there is no national legal framework for exposure to noise for the public or customers, how best to measure that noise to ensure that we do not expose our customers to health risks associated with high levels of noise.
Any plans to reduce noise pollution on the underground
Our maintenance programme, including track improvements and continual rail grinding to remove defects on the rail surface, helps to reduce noise and vibration. Over the last six months we have carried out 22,000 metres of rail grinding on the network. We spend approximately £150m each year on track improvements - this includes a dedicated annual budget of £1m to develop rail noise technology. We continue to deliver our rail grinding programme, adapting this as needed to the sections of track where noise is highest. We are planning to remove equipment which has led to greater corrugation from the network. However, this needs to be carried out in a measured approach so as not to worsen residential noise. In addition to this, TfL is investigating new engineering approaches to manage and reduce corrugation. This will reduce noise exposure for our customers and train operators. We recognise that automation of train operation can increase corrugation on the track (due to different driving and braking patterns). As a result, TfL has set noise isolation design requirements for future train rolling stock, such as the new Piccadilly Line fleet (which is the next London Underground fleet to be upgraded).
Any health impacts of the policy of keeping windows open on buses? For example, by recommending keeping windows open are you exposing passengers to more of London's toxic air - and is this reflected in your risk register(s)?
During the pandemic, we worked closely with researchers at UCL to mitigate the risks of Covid-19 for bus passengers. No additional health impacts were forecast as a result of the additional circulation of air between the saloon and the bus exterior due to the temporary policy of saloon windows remaining open, which is no longer in place since all Covid-19 restrictions were lifted. As part of the normal bus air circulation process, atmospheric air enters the saloon continuously from a combination of sources; such as the bus’s in built forced air ventilation system, heating system, passenger front and middle doors opening, windows and leakage from gaps in seals. The regular circulation of air is essential for many reasons, in particular to manage CO2 levels, passenger thermal comfort and prevent the build-up of airborne viruses, such as Covid-19. The policy of keeping windows open during the period of significant risk of Covid-19 transmission to passengers, enabled the normal process of air changing in the saloon to be maximised to reduce as much as reasonably practical any concentration of virus build-up within the saloon due to a potentially infected passenger. However the overall average air quality within the saloon will not have been affected as a result of increasing the cycle rate of air circulation change between saloon and ambient air.
Finally, any health risk registers for passengers TfL may keep .
We take the health and safety of our customers very seriously. While we don’t hold any risk register for noise exposure to passengers, we are considering how best to measure that noise to ensure that we do not expose our customers to health risks associated with high levels of noise. Anyone affected by noise can contact TfL’s dedicated customer services line, which is available 24 hours a day, seven days a week via the link below: https://tfl.gov.uk/help-and-contact/ If this is not the information you are looking for, or if you are unable to access it for any reason, please 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 Eva Hextall FOI Case Management Team General Counsel Transport for London
