Dangerous Breaths

by Derek Morrison

CarExhaustBreath in deep and suck it down
These invisible poisons in which you drown
The sunny road ahead could not be flatter
But you won’t see that particulate matter
From fresh air you can’t tell it apart
But it works its way to your heart
Suck it down as you keep fit
You won’t see anything in your spit
In your system it will weasel
Courtesy of that once green; diesel.

Diesel is a nasty fuel
Once considered the height of cool
By gullible politicians wishing to be seen
As not yellow, red, blue; but green
But now we know that at the root
That serious problems lie in the soot
That is bad; but there is a medley;
It’s partnered with oxides deadly
So breath in deep and suck it down
These invisible poisons in which you drown.

Of course your car is really great
Its fuel efficiency is up-to-date
And it provides the deep-throated power
That makes lesser mortals cower
But now there is much cause to worry
You may want to sell it in a hurry
Before the rush which will surely start
When people know about their heart
And then your fuel efficient machine
Will now be viewed as source unclean
Meanwhile; breath in deep and suck it down
These invisible poisons in which you drown.

[To listen to this verse select below]


I originally published this poem in 2015 and since then the scientific understanding has advanced somewhat – with findings even more depressing. I’ll address these updates at the conclusion of this postscript.

In summary, there are significant health threats posed by the increasing use of diesel fuel, particularly in Europe and specifically in the UK.  A significant contributory factor to the current dilemma is the chronic scientific illiteracy of the European policy makers (including UK politicians) which made them too amenable to the view of motor industry ‘experts’ that the improved fuel economy and reduced CO2 emissions from diesel engines would help the EU meet ambitious greenhouse gas targets.

In 2001, the then Labour government led by Gordon Brown gave a further consumer nudge towards diesel with new vehicle tax rates that focused on the carbon dioxide emissions as the key metric. Ironically, it was the the 1998 Labour government that had introduced a higher tax rate for diesel in recognition of its polluting nature. But despite the higher cost of diesel in comparison to petrol at the pumps the fuel efficiency advantages of diesel still outweighs this 1998 tax disincentive. Add to that continuing and new vehicle and company car tax incentives and it’s not surprising individual and corporate fleet buyers respond to these nudges towards diesel.

But fuel efficiency and greenhouse gas reduction has come at a serious and more pressing cost.

Simon Birkett, Head of Clean Air for London states:

“Since 1993, successive Governments have prioritised climate change over local air pollution – effectively killing people sooner – from the health effects of ‘carcinogenic’ diesel exhaust – rather than much later from the consequences of climate change. Their decisions then were irrational and delivered no climate benefits at a catastrophic human cost that will be felt for decades. (Source: Clean Air for London).

Diesel fuel does produce circa 15% less of the greenhouse gas carbon dioxide than petrol but it also produces nearly four times more oxides of nitrogen [a poison] and more than twenty times the particulate matter, i.e. ultrafine soot. The end result of that is an increased risk of heart attacks or strokes and damage to growing brains.

The motor industry’s (and consumer’s) blind focus on fuel efficiency and carbon dioxide emissions is leading us into a major public health disaster that is eventually going to force action. The current technological fixes are primitive, expensive, and largely ineffective for most commuter drivers. For example, diesel cars are now fitted with a Diesel Particulate Filter (DPF). A DPF is basically a soot trap attached to your exhaust system. Periodically, this soot builds up and then has to be burned off (you can sometimes see this burn-off being ejected when cycling behind a diesel vehicle – holding your breath won’t help much. In the average short distance commute, however, the engine and exhaust system of the average diesel car never gets hot enough and the result can be an expensively blocked DPF or the need to take the vehicle on a periodic high speed run to ensure the soot burn off – madness. Some opportunistic garages actually offer a DPF removal service, but changes to the MOT could make this an even more expensive mistake – again madness.

It boils down to this. The nature of diesel technology means it always burns with a yellow flame (unlike the blue of petrol) and, like a candle flame, yellow means soot and other byproducts are being produced. That soot and byproducts are non-trivial poisons that can enter your bloodstream via your lungs and so affect other major organs of your body.

The UK’s Channel4 television documentary series Dispatches transmitted The Great [Diesel] Car Con on 26 January 2015 which encapsulated the history and issues very well.

So what fuels the vehicle that currently carries your family and bicycles? Will that apparent fuel economy, low carbon dioxide emissions and vehicle tax still sway future car purchase decisions towards diesel?

Breath in deep and suck it down …

Update (27 June 2017)

Since first posting Dangerous Breaths in 2015 the anti-diesel polemic has grown significantly in the interim.

The great Volkswagen scandal of 2015 fed this particular fire. Volkswagen had introduced hidden modifications to its engine management software to detect when its diesel vehicles were being tested for exhaust emissions and so adjust the engine performance to produce favourable results not achievable in real-world driving conditions. The US Environmental Protection Agency (EPA) found, in September 2015, that the vehicles they tested were producing levels of oxides of nitrogen pollutants in real driving conditions that were up to 40 times more than are allowed in the US.

That translates into real-world impacts with headline grabbing figures asserting some 40,000 deaths a year in the UK as now being contributed to by outdoor air pollution (mainly affecting those who have underlying heart or respiratory disease). These terrifying figures are, understandably, scattered liberally by some politicians and environmental lobbyists. For a more detached scientific appraisal, however, it’s worth listening to part of an episode of the BBC Radio 4’s More or Less last broadcast on 27 November 2016 but still available in the BBC archive (circa 17 minutes 45 seconds into the episode). In summary, More or Less highlights, that while there is an undoubted statistical correlation between outdoor air pollution and early deaths, the actual figures are less concrete than politicians, lobbyists and the media would prefer. What is not in doubt, however, is the detectable pathological effects on the human cardiovascular, respiratory and nervous systems – even in otherwise healthy people – after exposure to oxides of nitrogen (image 1).

What's in the soot produced by internal combustion engines.
Image 1. What’s in the soot produced by internal combustion engines.

So we can say that air pollution has detrimental effects on human health and it will shorten human life, but the headline figures are just plain wrong. The trend is for air quality to get better driven, ironically, in large part by such publicity and political/public engagement.

But let us return to Volkswagen’s deception. Their corporate wickedness, again ironically, had the effect of waking up everyone to how:

  1. all manufacturers have been able to ‘game’ the standards system by ensuring that laboratory-based tests, undertaken in ideal environmental conditions and vehicle configurations, provided baseline reference values that were unrepresentative of real world environmental conditions and driving behaviours.
  2. politicians’ unwavering focus on long-term climate change mitigation by reducing CO2 emissions from vehicles – compounded by their general scientific illiteracy – had failed to immunise them from making decisions that were influenced by the commercial priorities of a major part of the motor-industry lobby.

Following the EPA findings of 2015, other real-world driving studies have uncovered equally disturbing results.

One useful example is provided by how internet shopping has increased the number of diesel-engine delivery vans on UK roads; mainly by Royal Mail, Amazon, supermarket chains; and other delivery services. Diesel engines become even more polluting when engines are placed under load – as is the case with a fully-loaded delivery vehicle covering many miles in concentrated urban settings. Emissions Analytics who specialise in real-world testing (see Sources below) carried out on-road tests of 26 such vans and found levels as high as 23 times the permitted level of oxides of nitrogen when vehicles were loaded. The worst offenders were the Mercedes-Benz Citan (23x) as used by some UK NHS ambulance trusts and the Fiat Doblo (18x) as used by Royal Mail. Other notables included the Peugeot 2-litre Boxer (14x), Ford 2.2 litre Transit (8x).

Circa 15% of UK traffic is vans but, yet, manufacturer testing is less stringent than that for cars with baselines established only on unladen vehicles. That enables the fitting of exhaust systems unsuited to conditions and driving patterns found in the real-world. Emissions Analytics publishes data via its EQUAIndex site (image 2) using an A-H scale with A being best. Comparing its EQUA AQ (air quality – oxides of nitrogen) and EQ CO2 indices is a worthwhile exercise. What’s particularly interesting is that some manufacturers seem perfectly capable of producing some models with very good real-world air quality indices, but yet others in their range are deplorable. Sadly, many manufacturer’s products currently appear to be just deplorable emitters of air pollution.

EQUAIndex sample
Image 2. an example of Emissions Analytics indices of real-world vehicle emissions

Gasoline/petrol vehicle owners may well be feeling somewhat smug at this point. Perhaps they shouldn’t be.

In early 2017 the respected Empa, the Swiss Federal Laboratories for Materials Science and Technology published their findings from their GasOMeP project (Gasoline Vehicle Emission Control for Organic, Metallic and Particulate Non-Legislative Pollutants). Their summary article Soot particles from GDI engines makes depressing reading.  If their results can be replicated by other research groups then it suggests that that the emerging generation of more fuel-efficient small petrol engines could also be contributing significantly to our global air pollution problem. A small engined petrol car purchased today with, say, a 1.2 litre direct injection turbocharged engine would easily produce the power equivalent of a much higher capacity engine of a decade ago. Good news for fuel efficiency, but perhaps less good news otherwise.

The GasOMeP project team compared 6 petrol direct injection vehicles manufactured between 2010-2016 with a diesel engine 2013 Peugeot 4008 with a Euro 5b emissions rating, i.e fitted with diesel particulate filter etc . All of the petrol cars emitted 10 to 100 times more fine soot particles plus up to 6 times more of the known ultra-carcinogen benzo(a)pyrene than the diesel Peugeot. The researchers concluded, therefore, that particle filters should also become mandatory for petrol/gasoline vehicles.

This is all depressing stuff but, as indicated earlier the trend seems to be for continuing improvement as long as pressure is maintained on vehicle manufacturers and technological development continue apace On the political front Transport for London will implement, from 23 October 2017, an additional ‘T’ or toxicity charge, of £10 for all cars, vans, HGVs, coaches and buses that don’t meet the minimum Euro 4/IV standard that enter the central London zone. Effectively, along with the current ‘C’ or congestion charge entering central London could cost a driver £21.50. While coaches and buses will continue to be exempt from the ‘C’ charge they will also now have to pay the ‘T’ charge unless they meet the minimum standards. Other cities are likely to follow this example. The intended effect is to drive older and, therefore more polluting, vehicles off the road.


Emission Analytics  (http://emissionsanalytics.com/)

EQUA Index  (http://equaindex.com/)

Transport for London

More or Less, BBC Radio 4, 27 November 2016 (at 17m:45s into episode)

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