"I would recommend passengers to sit as far as possible from the engine ..."

[whole diary]

[grahame]

From Chemistry World

Air on board diesel trains is five times more polluted than beside a busy street

Travelling on a diesel train can expose you to far higher levels of harmful particulates than standing beside a busy road, a Danish study has found. Diesel exhaust is associated with an increased risk of lung cancer, as well as other lung and cardiovascular diseases.

Those sitting on carriages being pulled by a diesel engine, especially close to the engine, breathe in a much larger dose of diesel fumes. Measurements revealed that ultrafine particles were 35-fold higher and black carbon or soot six-fold higher inside carriages pulled by diesel trains versus electric.1 Ultrafine particles are often carbon nanoparticles, coated with hydrocarbons and metals.

Long article - lots of data follows / worth a read.   Technical review / comments on how the figures might translate to UK^▸ (United Kingdom) trains and to diesel multiple units would be appreciated.

[CyclingSid]

Presumably for DMUs^▸ (Diesel Multiple Unit), sitting as far from the engines as possible means we will be travelling "Indian style", on the roof.

[grahame]

Presumably for DMUs^▸ (Diesel Multiple Unit), sitting as far from the engines as possible means we will be travelling "Indian style", on the roof.

This whole clean air in and around trains is interesting and perhaps it could become a major subject. The original article goes on to suggest that a train with a locomotive at the back is far better than a train with one at the front, so perhaps that means that the new Liverpool to Scarborough workings (Nova 3 - class 68 + 5 x Mk 5a coaches) will mean that a journey to Scarborough is far safer air-wise than the journey back home?  But then the research - and the image used on the original quoted article - appears to be older / less clean trains.

Searching a bit further, I found two more links

https://www.doranandmurphy.com/Cancer-Railroad-Exposures/Diesel-Fume-Exhaust-Exposure.aspx

https://www.thetimes.co.uk/article/all-diesel-trains-should-be-scrapped-by-2040-jojohnson-tells-railbosses-lt0pr38vf

and some pictures showing that if you think we may have a problem in the UK^▸ (United Kingdom) ...



Has anyone asked GWR^▸ (Great Western Railway), RSSB^▸ (Rail Safety and Standards Board), ORR^» (Office of Rail and Road formerly Office of Rail Regulation - about), Transport Focus or the train leasing companies about air cleanliness in UK trains??

[stuving]

My initial reaction to the article (not being able to read the reported paper) is that the conclusions are far more general than the data they are based on. While some aspects of the clean-up of diesel engines since the 1980s (when the ones on that line were built) have yielded less than expected, the latest car engines are as clean as petrol ones. So I can't see how the data can avoid being very specific to the trains, and operations, one the line(s) studied, and not general at all.

That raises another point, which has always puzzled me. Trains don't come under the same regime as buses and other road vehicles, but the NRMM category instead. That is essentially for industrial engines, but portable or self-mobile ones, and "not intended for carrying passengers or goods on the road". But the spatial relationship of DMU^▸ (Diesel Multiple Unit) engines to passengers is very similar to bus engines, isn't it? odd, really.

[CyclingSid]

The Public Health England Review of interventions to improve outdoor air quality and public health, appears to extol bi-modes over straight diesels. I can't see the connections between the text and the pages of references with the machine I am using here.

[PhilWakely]

The Public Health England Review of interventions to improve outdoor air quality and public health, appears to extol bi-modes over straight diesels......

So, they are saying that a journey from Newbury to Penzance (for example) in a bi-mode is better for you than in an ordinary diesel?

[smokey]

I expect it's far healthier to travel on a diesel train than on a diesel bus, likewise standing at a station waiting for a train would be better than waiting for a bus on a busy road.

[Lee]

The Public Health England Review of interventions to improve outdoor air quality and public health, appears to extol bi-modes over straight diesels......

So, they are saying that a journey from Newbury to Penzance (for example) in a bi-mode is better for you than in an ordinary diesel?

Whether it is or it isnt, I find it far more f****** depressing in a bi-mode, which is why I dont do it any more...

[Red Squirrel]

Out of interest I wonder what studies have been made of steam locomotive particulate emissions? Perhaps not a major concern to those of us who may visit one or two preserved railways a year, but for the people who regularly drive and fire preserved locos, and for on-train staff, the exposure is presumably more of a concern.

[stuving]

Out of interest I wonder what studies have been made of steam locomotive particulate emissions? Perhaps not a major concern to those of us who may visit one or two preserved railways a year, but for the people who regularly drive and fire preserved locos, and for on-train staff, the exposure is presumably more of a concern.

It's going to be hard to find out, as the phrase "steam locomotive particulate emissions" gets several hits but they appear to all be passing comments in introductions and the like. Plus of course the post quoted here will get hits too ...

But surely "steam locomotive" is not a relevant category; isn't it the fuel that counts? So you would expect different effects for coal, wood, oil, and electric-fuelled steam locomotives.

[Red Squirrel]

...you would expect different effects for coal, wood, oil, and electric-fuelled steam locomotives.

Indeed; there's also quite a difference between a Great Western loco running on good Welsh steam coal, and a loco from one of the also-ran railways running on lignite...

[Robin Summerhill]

...you would expect different effects for coal, wood, oil, and electric-fuelled steam locomotives.

Indeed; there's also quite a difference between a Great Western loco running on good Welsh steam coal, and a loco from one of the also-ran railways running on lignite...

You need to go back a long time to find GWR^▸ (Great Western Railway) engines running on "good Welsh steam coal"

What there was was being exported post-war, and the railways were having to make do with coal dust glued together with concrete (ovoids and briquettes). That's why so many draughting modifications were carried out at Swindon in the 1950s to make the blighters steam at all.

[eightonedee]

I expect it's far healthier to travel on a diesel train than on a diesel bus, likewise standing at a station waiting for a train would be better than waiting for a bus on a busy road.

It depends on the layout and design of the station.

One of the problems with the "new" Reading Station is that when the wind is in certain directions, and there are diesels idling on the platforms (remember we still have Turbos, and then there are the Cross Country Voyagers), the covered over bridge fills with diesel fumes.

It is not helped by the habit of holding a number of Turbos waiting to go to the depot, all at platforms idling, although this is a much reduced problem now most have been replaced by Electrostars, or by the Cross Country trains having prolonged waits at Reading during their reversal there, again with engines running. We really need them to cut their engines off, and if they need electricity for services while standing, perhaps a "shore supply" and connection could be arranged for them while they do so if their batteries are not up to it.

As for pollution from steam engines, remember they largely operated in an era when highly polluting coal provided most of our electricity, town gas, domestic fires etc, when we had pea-souper fogs and in the industrial north net curtains had to be replaced regularly as the sulphurous air dissolved them.

[Oxonhutch]

Out of interest I wonder what studies have been made of steam locomotive particulate emissions? Perhaps not a major concern to those of us who may visit one or two preserved railways a year, but for the people who regularly drive and fire preserved locos, and for on-train staff, the exposure is presumably more of a concern.

Not a concern, I assure you. The aroma of their emissions is just one of the reasons I volunteer!

Ahh, steam ... ,
and soot, clinker, vaporised oil, coal dust, ash ...

[Robin Summerhill]

Whilst I understand 81D's misgivings about diesel fumes in stations (and the worst by far that I have ever encountered is on the footbridge at Manchester Victoria where the DMUs^▸ (Diesel Multiple Unit) idle immediately below it), the original thread was about the on-train situation.

Something that crossed my mind is that these days the vast majority of stock is air conditioned and there isn't much stock still running with opening windows. As I see it therefore, if you are travelling in what is essentially a semi-sealed box, air pollution from outside whilst on the move is going to be minimal. And in addition, if pollution is coming into the coach via the aircon, it's not going to make any difference whatsoever which coach you are in.

So I suspect that this latest scare story report only really applies to older stock with opening windows.