Air quality on London Underground

[bramling]

Is there any evidence of lower life expectancy / increased respiratory distress (right term?) in operational/formerly operational TfL staff than comparable Londoners?

There’s certainly a perception that there seems to be a disproportionate number of apparently healthy drivers who retire after a long service of driving Tube trains, then relatively soon afterwards the bad news comes that they’ve passed away unexpectedly from something. This is all very anecdotal though, as there are lots of factors why Tube drivers might not be particularly healthy, not least shift work plus spending long periods sitting down.

On the assumption the concerns raised in this thread are credible it seems like something that should be relatively easy to do a quick study on and a reasonable argument it should be funded by TfL. The results of that study should then inform what, if anything, is done.

Whilst I agree, it’s something the powers that be would want to avoid, as it is opening the most almighty can of worms. There’s enough of a can of worms with driver finding themselves with hearing problems.

 

[Horizon22]

There’s certainly a perception that there seems to be a disproportionate number of apparently healthy drivers who retire after a long service of driving Tube trains, then relatively soon afterwards the bad news comes that they’ve passed away unexpectedly from something. This is all very anecdotal though, as there are lots of factors why Tube drivers might not be particularly healthy, not least shift work plus spending long periods sitting down.




Whilst I agree, it’s something the powers that be would want to avoid, as it is opening the most almighty can of worms. There’s enough of a can of worms with driver finding themselves with hearing problems.

This is anecodtal across the whole industry though; especially for those that have spent 30-40 years in the industry who maybe don't have a huge social gathering or many activities outside of work. The lack of that interaction, structure as well as likely poor health habits due to shift work and worktype can sometimes cause a rapid decline. It's not universal but as you say, within 12-18 months it's not unknown for there to sadly be a funeral.

I don't think we'll be seeing widespread station closures, but TfL may have look at exposure (e.g rotating so you only spend X amount of hours on the platform at a time) or other methods (such as masks, which imao would be one setting after Covid that they might be justified).

 

[philthetube]

Is there any evidence of lower life expectancy / increased respiratory distress (right term?) in operational/formerly operational TfL staff than comparable Londoners?

On the assumption the concerns raised in this thread are credible it seems like something that should be relatively easy to do a quick study on and a reasonable argument it should be funded by TfL. The results of that study should then inform what, if anything, is done.

This is the question which will answer all others in this thread.

I'm sure I recall reading that life expectancy among Tube drivers is quite poor. I don't know about others.

you would need to compare with the life expectancy of bus drivers to get any idea if this was down to environmental conditions.

 

[HSTEd]

Open Access journal paper:

https://www.sciencedirect.com/science/article/pii/S0048969722064142

Press Release for above paper (including layman's summary of findings):

Tube air quality worst at rush hour

A Surrey-led study finds London Underground air quality dips most during evening rush hour, pointing to a need for better ventilation. Find out more.

www.surrey.ac.uk

Ventilation improvements in deep tube stations is going to be a major engineering task unfortunately.

Platform Screen Doors are likely to be rather expensive, but at least allow various operational improvements.

 

[AM9]

- rheostatic braking is already used to reduce brake dust for instance.

Aren't the later tube trains now all Regenerative braking, which actually does something useful by returning reverse traction current for other trains to use. Rheostatic braking is where the energy is deliberately wasted in on-train resistors which then heat up the tunnels, - the last thing that the tube needs! The resistors are only there in case the traction supply (temporarily)* can't handle the return current. Even the Woodhead class 76 & 77 had regen., so it is hardly novel.

* The Victoria Line 2009 stock has full regen, but it was necessary to turn this capability off and dissipate the braking energy in the on-board resistors whilst there were still some of the old fleet of 67 stock trains running on the line. This caused a considerable rise in ambient temperature along the line.​

 

[Mawkie]

Is there any evidence of lower life expectancy / increased respiratory distress (right term?) in operational/formerly operational TfL staff than comparable Londoners?

On the assumption the concerns raised in this thread are credible it seems like something that should be relatively easy to do a quick study on and a reasonable argument it should be funded by TfL. The results of that study should then inform what, if anything, is done.

LU have agreed to release (hopefully, anonymised) sickness/absence records from staff from 2014-2019 to Imperial College to allow for an in depth study into the long term health of operational staff. In addition to this, pension records have also been made available - which will, rather gruesomly I suppose, indicate the length of time that staff live after they retire.

Results of this latest study are expected in late 2024.

 

[Nym]

No matter what the findings are. It’s not going to change what TfL does with its staff and platforms

 

[Mawkie]

No matter what the findings are. It’s not going to change what TfL does with its staff and platforms

What makes you say that?

 

[bramling]

Aren't the later tube trains now all Regenerative braking, which actually does something useful by returning reverse traction current for other trains to use. Rheostatic braking is where the energy is deliberately wasted in on-train resistors which then heat up the tunnels, - the last thing that the tube needs! The resistors are only there in case the traction supply (temporarily)* can't handle the return current. Even the Woodhead class 76 & 77 had regen., so it is hardly novel.

* The Victoria Line 2009 stock has full regen, but it was necessary to turn this capability off and dissipate the braking energy in the on-board resistors whilst there were still some of the old fleet of 67 stock trains running on the line. This caused a considerable rise in ambient temperature along the line.​

Yes everything from the 90s onwards has regenerative capability. There’s still plenty of friction braking going on though Firstly rheo/regen braking naturally only occurs on the motor cars (though this is able to provide most braking effort). Secondly emergency braking uses friction braking only, so occasionally there will be a friction application if an emergency brake application occurs for whatever reason. But more recently some of the ATO systems have designed in occasional friction brake applications in order to prevent glazing of the brake blocks. To be fair all this combined doesn’t amount to much, the vast majority of braking on LU is rheo/regen.

 

[Nym]

What makes you say that?

A couple of decades of railway grade cynicism?

Also the knowledge that over 10 years ago, studies were being funded, and were completed, but were never published.

In response to other comments about brake resistors heating up the tunnels, I'd like to ask, where do you think the KE goes when it's dispersed into friction brakes?

 

[AM9]

A couple of decades of railway grade cynicism?

Also the knowledge that over 10 years ago, studies were being funded, and were completed, but were never published.

In response to other comments about brake resistors heating up the tunnels, I'd like to ask, where do you think the KE goes when it's dispersed into friction brakes?

The kinetic energy on rheo or friction is of course heat which is dissipated locally. The difference is that part of the reason for rheo/regen introduction was to allow more aggressive service braking with less wear and tear on frictional braking components which also means less dust. So the only way to minimise local heating is to export the energy via the DC supply, which in part then also cancels out part of the energy used by other trains in the (electrical) section, which works well with high acceleration and deceleration operation.

 

[Wolfie]

No matter what the findings are. It’s not going to change what TfL does with its staff and platforms

It absolutely will if they face a class action or indeed enforcement action from the HSE.

 

[Nym]

It absolutely will if they face a class action or indeed enforcement action from the HSE.

I'm going to sound like a broken record here soon.

What exactly would the class action achieve against a government organisation, and what will the HSE be able to 'enforce' against TfL / LUL?

 

[bramling]

It absolutely will if they face a class action or indeed enforcement action from the HSE.

Can’t help but be cynical about this. Public bodies don’t generally take action against other public bodies, especially when it would be committing the golden sin of raising a problem for which no one really has a solution, especially as to actually address any issue would extend *well* beyond the lifespan of political and/or management cycles.

Incidentally, to clarify I’m not saying that this issue *shouldn’t* receive attention, rather that I simply don’t think it will.

 

[Wolfie]

I'm going to sound like a broken record here soon.

What exactly would the class action achieve against a government organisation, and what will the HSE be able to 'enforce' against TfL / LUL?

One or more TUs could bring a class action. The HSE can absolutely legitimately bring legal action against any body not complying with its obligations under the Health and Safety at Work Act.

 

[HSTEd]

One or more TUs could bring a class action. The HSE can absolutely legitimately bring legal action against any body not complying with its obligations under the Health and Safety at Work Act.

Health and Safety at Work Act requires reasonable adjustments.

There arent many adjustments that can be made without massive spending that are likely to achieve much at all.

Indeed it could easily become counterproductive for staff since the most effective intervention is the forbidden technology that would save lots of staff from the pollution .....

 

[Bletchleyite]

Health and Safety at Work Act requires reasonable adjustments.

There arent many adjustments that can be made without massive spending that are likely to achieve much at all.

For drivers specifically (who spend most time getting a noseful of brake dust) surely it would be viable to improve sealing of the cabs and install HEPA filtered cab ventilation?

Harder to provide for platform dispatch staff, though could it be investigated moving them into elevated glass boxes as dispatchers tend(ed) to be on German U-Bahnen which could have the same filtered air supply? Or even move them off the platforms and give them CCTV instead?

 

[Mawkie]

For drivers specifically (who spend most time getting a noseful of brake dust) surely it would be viable to improve sealing of the cabs and install HEPA filtered cab ventilation?

Harder to provide for platform dispatch staff, though could it be investigated moving them into elevated glass boxes as dispatchers tend(ed) to be on German U-Bahnen which could have the same filtered air supply? Or even move them off the platforms and give them CCTV instead?

Exactly this!

IIRC CSAs don't currently do more than 2hrs on sub surface platforms. This could easily be amended to 15mins, or whatever is deemed safe.

They could also increase the general cleaning regime on stations and platforms, and intensify the tunnel cleaning regime too.

They had a tunnel cleaning train at one point, but I think it may have dislodged some asbestos. The answer to that would be shutting down parts of the central section for an intense, once in a lifetime, cleanse of the tunnels with appropriate safeguards in place.

 

[Nym]

There was also a new tunnel cleaning train. But there were some fundamental issues

 

[Mawkie]

There was also a new tunnel cleaning train. But there were some fundamental issues

I don't quite recall, perhaps you could elaborate? The one I'm thinking of blew jets of compressed air as it travelled along, with a huge vacuum cleaner towards the rear which supposedly sucked up all the loosened particles?

 

[Nym]

I don't quite recall, perhaps you could elaborate? The one I'm thinking of blew jets of compressed air as it travelled along, with a huge vacuum cleaner towards the rear which supposedly sucked up all the loosened particles?

Pretty much the concept. And it would have worked but there were oversights when the detail came to light

 

[bramling]

Exactly this!

IIRC CSAs don't currently do more than 2hrs on sub surface platforms. This could easily be amended to 15mins, or whatever is deemed safe.

They could also increase the general cleaning regime on stations and platforms, and intensify the tunnel cleaning regime too.

They had a tunnel cleaning train at one point, but I think it may have dislodged some asbestos. The answer to that would be shutting down parts of the central section for an intense, once in a lifetime, cleanse of the tunnels with appropriate safeguards in place.

I really don’t know where they would even start with a clean. It wouldn’t take many nights of engineering work or whatever to end up back to square one. It isn’t just train braking that produces dust. It is absolutely everywhere, and the older lines have so many boltholes and odd-shaped spaces that cleaning the tunnels thoroughly would be pretty impossible.

 

[Dstock7080]

From a June 2023 document entitled "Air Quality Partnership":

Underground particulate matter composition:

 

[321over360]

I found this on Youtube where one of the Headlines (scroll forward to 01:50 on the Video) where the headline is about toxic air on the Tube back in 2001 and how it is bad for your health so Tube air has been reported as Toxic