I would like access to information regarding air quality at the platform level within Underground stations. Specifically I would like to see data regarding measured particulate matter in the air, by station platform. Please let me know the process for requesting this data (for example, if there is a form to be completed), if this email will not suffice. And the expected timeframe to access the data.

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Our ref: FOI-2495-1819

Thank you for your request received by Transport for London (TfL) on 18 December 2018 asking for information about London Underground air quality. I am sorry for the delay in replying.

Your request has been considered in accordance with the requirements of the Environmental Information Regulations and our information access policy. I can confirm we hold some of the information you require.

At London Underground the safety of our customers, our people and contractors is our number one priority. We regularly review air quality across the network and this shows that at its worst the level of dust and particulate matter in the air is about 1/4 of the maximum safe level set by the Health and Safety Executive. This is in spite of rising customer numbers, significant increases in service, like more trains on the Victoria line and the introduction of Night Tube, and the consequent increased level of upgrade and maintenance works associated with this growth.

We measure the air for specific metals and respirable dusts (PM 4.0) This refers to the aerodynamic diameter of the dust particles measured; a PM 4 measurement would be for particles under 4 microns in diameter.  The source of these are mainly track, wheel and brake wear. We do not routinely measure surface pollutants (Nox, Ozone etc) as these are not generated inside the network. Measurements are generally taken for whole work shifts and are considered against the Health and Safety Executives EH40 document (workplace exposure limits).

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.

We publish environment reports annually on our website including air quality on the underground. The most recent report published is the 2017 report, which can be found here:

https://tfl.gov.uk/corporate/publications-and-reports/environment-reports#on-this-page-1

We expect to be able to publish the 2018 report soon.

You may also be interested in the air quality on the Tube report we commissioned which can be found via the link below:

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

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

Sara Thomas

FOI Case Officer

FOI Case Management Team

General Counsel

Transport for London

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