Please give me details of the amount of pollution Tube passengers are exposed to on the different lines operated by TFL/London Underground. Please provide any official correspondence from TfL to staff or unions discussing the health risks to staff or passengers because of high pollution levels. Please provide details of any official complaints received in the past 24 months relating to health concerns of people using the Tube because of exposure to pollution.

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Our Ref:          FOI-2759-1819

Thank you for your request received on 21 January 2019 asking for information about 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 TfL does hold the information you require. You asked:

• Please give me details of the amount of pollution Tube passengers are exposed to on the different lines operated by TFL/London Underground.

We routinely monitor and undertake dust surveys across in the network to evaluate staff and customer exposures to respirable and inhalable dusts. The composition of London Underground dust has been a topic for discussion for many years and over that time the main characteristics have not changed. The particulates below ground in London Underground infrastructure are predominantly iron oxide particles from track, wheel and brake wear.

We are committed to maintaining the cleanest air possible for our staff and customers when using the Tube. London Underground continues to operate well within the Health and Safety Executive exposure limit in spite of the increased demand, higher level of service and increased level of upgrade and maintenance works being delivered in recent years. In addition TfL has informally adopted a much stricter target to meet the recommendations of the Institute of Occupational Medicine (May 2011) to limit inhalable dust exposures to less than 5mg /m3 and Respirable Dusts to 1mg/m3. Moreover, with staff shifts running for 7-8 hours, it is assumed that any exposures by non-employees, primarily customers, will be significantly lower than that for employees.

Dust levels fluctuate from year to year. To ensure that dust levels remain low and within acceptable levels, London Underground has a stringent cleaning regime. This is to ensure a more pleasant environment for customers and staff, and prevent dust from interfering with the functioning of electrical equipment. As new trains are commissioned, London Underground requests the installation of “rheostatic” braking, which reduces the friction action of brakes on wheels by using the engine power to brake the train, thereby reducing the amount of dust produced.

The main pollutants we measure on the London Underground are respirable dusts (PM 4.0) and specific metals. The source of these are track, wheel and brake wear. We do not routinely measure surface pollutants (Nox, Ozone etc) as these are not generated inside the network.

The bulk of monitoring is undertaken in train driver cabins and at stations. Measurements are generally taken for whole work shifts and are considered against the Health and Safety Executives EH40 document (workplace exposure limits).

Please find attached additional information (FOI-2759-1819) that summarises dust levels on the London Underground. All measurements are in mg/m3. All samples are taken over work shift periods of 8 hours.

Slide 1:
Average driver exposures to respirable dust for each deep tube line – 2017
Average exposure to respirable dust for a selection of stations – 2017

Slide 2:
Historical exposures (respirable dust) 2005-2017. Jubilee, Piccadilly and Northern Line

Slide 3:
Historical exposures (respirable dust) 2005-2017. Bakerloo, Victoria and Central Lines

Slide 4:
Average respirable dust exposures at deep tube stations 2005-2017

Slides 5, 6 and 7:
Respirable dust levels at selected deep tube stations

Please also find attached a summary of the recent work we have done measuring passenger journey exposures (Simulated Passenger Journeys – Summary of Results) as well as information on historical metal dust levels – the exposure groups are drivers (Summary of LU Operator Metal Exposures in mg-m3 (8hr TWA)). The predominant compound in rail dust is iron oxide.

These are the exposure limits published in EH40/2005 for those specific metals:

https://www.hseni.gov.uk/sites/hseni.gov.uk/files/publications/%5Bcurrent-domain%3Amachine-name%5D/eh40%20August%202018.PDF

Please note that there is no data for 2015 as sampling was not funded.

The Committee on the Medical Effects of Air Pollutants (COMEAP) have also recently published an article on air quality on the London Underground that might be of interest:

https://www.gov.uk/government/publications/particulate-air-pollution-on-london-underground-health-effects

• Please provide any official correspondence from TfL to staff or unions discussing the health risks to staff or passengers because of high pollution levels
• Please provide details of any official complaints received in the past 24 months relating to health concerns of people using the Tube because of exposure to pollution

Given the extent of the information you are looking for, we are applying Regulation 12(4)(b) as we believe that the request is ‘manifestly unreasonable’ because providing the information you have requested would impose unreasonable costs on us and require an unreasonable diversion of resources.

We have established that the potentially relevant information which we hold regarding healthy risks to staff or customers covers a significant period of time and would comprise of hundreds of potentially relevant emails, all of which would have to be reviewed in response to your request.

Additionally, we do not record complaints in a way that would allow us to extract the requested information. We have done an initial search using the codes used for air, noise, and air pollution, which has resulted in over 2,500 cases. We would need to review all of these cases to confirm whether it refers to a health complaint. We have also carried out a search using the code for health complaint, we have identified 15 cases which we could provide details of. However, this is unlikely to be all of the complaints we have received relating to health complaints resulting from pollution on the London Underground.

The use of this exception is subject to a public interest test, which requires us to consider whether the public interest in applying the exception outweighs the public interest in disclosure. We recognise that the release of information would promote accountability and transparency in public services and also help address your particular concerns about this issue. However, the time it would take to provide the information you have requested would divert a disproportionate amount of our resources from its core functions and on balance we consider that the public interest currently favours the use of the exception.

We will consider your request again, if you are able to narrow its scope so that we can more easily locate, retrieve and extract the information you are seeking. If you have specific questions we will be happy to consider those.

Please see the attached information sheet for details of your right to appeal.

Yours sincerely

Gemma Jacob
Senior FOI Case Officer
FOI Case Management Team
General Counsel
Transport for London

[email protected]

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