Tag Archives: air pollution

And pork barrel politics might save some more lives

I mentioned last week, in the wake of Street Talks on the topic of Clean Air in London, that electrification of the Great Western Main Line will help clean up the air in Bristol, Cardiff, and West London by retiring the old diesel Intercity 125s. As part of the project, the government will be spending a lot of money on hybrid trains which can switch from electric to diesel where the power lines run out on secondary routes. It’s almost, but not quite, unique: most countries are not as shy about investing in proper electric railways. Hauling heavy fuel and engines around is pretty wasteful and wears out the infrastructure quicker than fully electric trains. But, still, hybrids are less bad than pure diesels where electricity is available.

The newspapers aren’t interested in the fact that we’re spending lots of money on bizarre hybrids whose engines will probably long outlast the remaining supply of affordable diesel, when we could be investing in doing electrification properly, as no doubt we eventually will have to do one day. The scandal from their point of view is over the manufacturer. After Bombardier of Derby (nobody mention that they’re Canadian) lost out to Siemens of Germany in the bid to build new Thameslink trains, The Guardian and the unions have decided that Bombardier are the last bastion of Great British Manufacturing (and definitely not just another large multi-national corporation with no special attachment to their UK operations or workforce). Having completed the new Victoria Line and London Overground trains, Bombardier are running out of things to do in Derby and handing out hundreds of redundancies — many of them to residents of the marginal South Derbyshire constituency. And then the government go and give yet another train building contract to a foreign company — Hitachi, who will build the new hybrid trains in Country Durham — instead of the Great British Bombardier. It all makes for a very convenient stick for government bashing.

Look at the teeny tiny little windows. (John Turner / CC BY-NC-ND)

But the government might have conveniently found something for Bombardier to do in the DfT’s big pile of previously abandoned projects. Bombardier built the Voyagers and Meridians — those nasty noisy, smelly, dark and cramped diesel successors to the Intercity 125s used by CrossCountry and Virgin on the avoiding-London intercity routes and East Midland between St Pancras and Sheffield. Bombardier could now build extra carriages to increase the capacity on those trains.

But they’ve come up with something extra special to keep Bombardier busy. These trains already have electrical rather than the more common mechanical transmission: the engines are generators, the wheels are powered by motors. So rather than just building more of the same carriages, the new ones could be fitted with all the equipment to draw power when under wires and to switch all the motors between power sources. They would become hybrids. If built, CrossCountry could switch off the engines around Edinburgh, Leeds, Manchester, and Birmingham; East Midland could stop burning fuel under the wires in the London suburbs. It’s might be silly to choose to build new hybrids instead of proper electrification, but since we’re already burdened with the bloody Voyagers, converting them would seem the sensible thing to do — nay, the critical thing to do given the scale of the air pollution problem.

Of course, it might never happen. The government have been cast as the baddies in the Bombardier story and Philip Hammond has instructed civil servants to look through the pile of previously discarded projects for anything mentioning Bombardier so that he can make himself look busy and sympathetic. But if the news story dies of natural causes, as they so frequently do, the project might be quietly filed away again.

In which the EU nudge the coalition* to quietly save a lot of lives

To transport nerds like me and Tom, something stood out in Simon Birkett’s Street Talk about air pollution in London:

When you map air pollution levels in central London you get an only very-slightly fuzzy road map, of course. But that other thing — you see the other thing, more polluting than anything else on the map?

You can see it when you look at the whole city — three things that aren’t roads clearly stand out:

Well one of them is obviously Heathrow Airport, way out west, but those other two…

It’s those old Intercity 125s, high speed diesel trains on London’s remaining major non-electrified railways** — the Great Western into Paddington, and the Midland into St Pancras. You might also spot a lesser line, the Chiltern to Marylebone (Waterloo, Euston, and King’s Cross also still get a very small number of diesels, but not enough to leave any obvious trace on the map).

Makes one wonder how bad the air is in Bristol and Cardiff, where all the trains are diesel.

For most of the day, Paddington hosts half a dozen or more old Intercity 125s each hour from the Westcountry and South Wales. That’ll change when lines to Bristol, Cardiff and Oxford go electric over the next few years. The long distance trains will either be electric, or bizarre hybrids that will burn fuel only where the power lines run out on a few routes.

The £1 bn electrification of the Great Western lines is being sold by Philip Hammond and the DfT almost entirely as an investment to improve speed (always the obsession with speed!) and capacity — the electric trains will accelerate faster, cutting perhaps as much as a fifth from the journey time when combined with other line upgrades. (Trains to Swansea will have to be bizarre hybrids, carrying the dead weight of fuel and engines all the way from London, because the final few miles beyond Cardiff won’t be electrified on the grounds that there are other physical constraints on journey times between Swansea and Cardiff — always the obsession with speed!)

But crucial to the electrification project are EU carbon emissions and air pollution regulations, both of which are tightened again next year: they make it more expensive to build and buy compliant diesel engines, and they mean that money is thrown away on mitigation and fines, costs which seal the case for electrification. Without such regulations pushing up the cost of diesel, the current occupants of the Treasury would never have agreed to spending the money on wires.

And yet the fact that electrification will reduce the incidence of childhood asthma and horrible deaths from respiratory diseases in Cardiff and Bristol and West London doesn’t seem to be something that the government wants to boast about. To boast about solving air pollution would require first that the government publicly acknowledge the frightening scale of the air pollution problem — and then that they acknowledge that, without the EU, they never would have bothered solving it.

* After six Labour transport secretaries did nothing, the final one, Adonis, succeeded in getting electrification announced, only for an unfortunate general election to fall between the announcement and his being able to implement it.

** Yes, I know they are both electrified within London for some commuter services.

Street Talk #6: Clean Air London

Don’t forget, y’all: Street Talks returns from the summer break on Tuesday week, the 6th, upstairs at the Yorkshire Grey from 7pm. Do come along?

The topic is air pollution, and the speaker is Simon Birkett. Air pollution causes thousands of premature deaths in London each year, mostly through disgusting lung diseases, and it exacerbates those diseases that are caused by sedentary lifestyles. However, unlike sedentary lifestyles, there isn’t any way for individual Londoners to opt out of the effects of air pollution. As usual, there is more on the Liveable London website.

Passive driving

“The ideal of the ethical man,” wrote the great Victorian scientist and liberal Thomas Henry Huxley, “is to limit his freedom of action to a sphere in which he does not interfere with the freedom of others.”

At Bath Skeptics in the Pub in April, Ian Walker talked about transport-related (ir)rational behaviour and policy.  One of the ideas he talked about was “passive driving”.  The analogy, of course, is to passive smoking.  Every time a smoker lights up in a restaurant or pub or club, the health and life expectancy of all the diners, punters, and staff around that smoker takes a tiny hit.  And those people get nothing positive in return.  In a liberal society, we defend the right of smokers to give themselves horrible slow fatal diseases.  But we expect them not to interfere with the rights of everyone else to their health.  And on the occasions when they can not show that restraint voluntarily, we have to resort to legislation banning smoking in restaurants and pubs and clubs.

Similarly, every time you get into your car and fire up the engine, my health and life expectancy takes a hit, and I get nothing in return.  You get to work or to the shops or to a day out, but I get nothing except a reduced life expectancy. Every time you get in the driving seat, you are making the decision that your journey is worth more than my and everybody else’s health and wellbeing. How big a problem is it?

Well, before the ban on smoking in enclosed public spaces and workplaces, estimates were that around 600 people in the UK were dying prematurely each year because of exposure to second-hand  tobacco smoke in those environments.

Exposure to driving in the UK annually causes:

  • over 2,000 deaths in what the DfT describe as road “accidents”, of which less than half are of car users (stats for drivers and passengers are, sadly, all combined). Around 500 pedestrians, just over 100 cyclists, around 500 motorcyclists and a few bus and coach passengers are killed in “accidents”.  A few of those deaths will have nothing to do with cars — indeed, some genuinely will be “accidents” — but most are in some way the consequence of other people choosing to get in a car, a choice that would never bring any benefit to the person killed. As Harry Rutter pointed out at Street Talks, pedestrian deaths are particularly high in children, the elderly, and the lowest socio-economic groups: people to whom the benefits of car use are often out of reach, but who have to suffer the negative consequences regardless.  Motor vehicles are the biggest cause of death in teenagers, who should have a large proportion of their lives ahead of them, arguably making road “accidents” a more important issue than diseases which kill late in life and thus take away fewer quality life years.
  • Air pollution is not a fashionable topic, yet estimates of UK deaths attributable to it are even higher than for crashes, ranging from 12,000 to 35,000. Motor vehicles are not the only contributor to air pollution, but they are the major one.  Air pollution is especially a problem in cities, paradoxically the places that usually have the highest proportion of non-car users.  People living happily in cities without a car — who have perhaps even made the conscious decision to live somewhere within walking or cycling distance of employment and shops and services — again have to deal with the negative consequences of people driving into and through their city.
  • Diseases associated with obesity and sedentary lifestyles are amongst the biggest killers of our time: cardiovascular disease, cancers, diabetes, even dementia.  We know that these diseases can be prevented or delayed by regular exercise — cycling, for example — and that exercise is therefore one of the biggest predictors of life expectancy.  But while a great many people in the UK would like to be able to make their regular short journeys by bicycle (not so much because they worry about their health, but because it’s cheap and simple), very few do.  The overwhelming reason people give for not cycling is that the roads are far too uninviting: because they’re full of fast moving and badly driven motor vehicles.  Every time somebody chooses to drive a car, the rest of us get none of the benefit, but we do get dangerous, intimidating, noisy and smelly streets, in which normal people will never want to ride a bicycle.

That’s just to list the obvious ways that other people choosing to drive has negative health consequences for you and me.

I was reminded of all this because today the Association of British Nutters Drivers are back in the news demanding their freedoms.  Nurse turned Tory MP, and now parliamentary under-secretary of state for health, Anne Milton said last week that allowing residents to close their residential streets to motor vehicles on sundays so that their kids can go out and play might be a good thing.  The ABD are said to be amazed that their freedom to drive wherever and whenever they like might, for just one day a week, come second to other people’s freedom to choose how to use just a little bit of their own neighbourhood. Once again, the ABD behave like spoiled children, throwing their toys around when told it’s somebody else’s turn to play.

The ideal of the ethical man is to limit his freedom of action to a sphere in which he does not interfere with the freedom of others.  The Association of British Drivers fail at this most basic principle of ethics.

That’s not what I said, say scientists

According to SCIENTISTS, “pollution is not improved by c-charge.”  (“Improved”? These scientists are so sloppy with their language.)

Journalists all over the city are this week reporting that the congestion charge has not reduced air pollution problems in central London, and that’s a fact, proven by science.  (As far as I know, the CCharge was never about air pollution — the clue’s in the name. But it’s potentially an interesting thing to look at all the same.  I can invent in my head plausible hypotheses for why it would improve air quality, and why it wouldn’t, but both would be useless without evidence either way.)

Unfortunately, I’m having a little trouble finding out who these so-called scientists quoted as the source for the claim are.  I asked scientists on twitter, but they couldn’t remember making the statement.

What I can easily find is a set of documents (none of them making the claim) reviewing work that explores a potential link between the CCharge and air pollution.  The documents are not new research published as peer reviewed articles in a scientific journal.  They are a “research report” — a King’s College academic’s review of what we know about the CCharge and air pollution — coupled with commentary and a press release.  The documents are all commissioned and published by the “Health Effects Institute“,

a nonprofit corporation chartered in 1980 as an independent research organization to provide high-quality, impartial, and relevant science on the health effects of air pollution. Typically, HEI receives half of its core funds from the US Environmental Protection Agency and half from the worldwide motor vehicle industry.

And that’s fine.  If the content is good, it doesn’t matter who funded it or where it was published.  I’m merely establishing exactly who is saying what.  The exact people are:

  • Professor Frank Kelly, an environmental health researcher specialising in air pollution, who (as leader of an independent group of scientists) wrote the comprehensive research report reviewing the evidence.
  • HEI’s Health Review Committee, who wrote a short commentary on Kelly’s research report.
  • HEI’s press office, who wrote the press release, which is the only thing that most journalists read.

The main line of research reviewed by Kelly looked at roadside and background levels of nitrogen oxides (NOx), carbon monoxide (CO) and small particulates (PM10).  The data compared the change (if any) in these pollutants at locations within the CCharge zone from a few years before implementation to a few years after implementation.  It did the same for control locations in London but outside of the CCharge zone, to account for any unrelated trends in air pollution.

Kelly’s report concluded that there was no evidence of a CCharge effect on roadside levels of NOx; a complicated effect on background levels of NOx (whereby one type was marginally reduced and another type increased, especially near the boundary of the zone); but a marginal reduction in carbon monoxide and a reduction in particulates becoming more pronounced the closer one gets to the CCharge zone.  So the overall conclusion is that there is a small amount of evidence to indicate that the CCharge has made a small reduction to air pollution (the exact opposite of the claim attributed to “scientists” in the headlines).  However, the data was extremely limited — in some cases to single data points — and Kelly’s report doesn’t put much weight on any of the conclusions.

Even where there is sufficient data, Kelly’s report indicates that there are limitations to what this kind of data can say about the CCharge effects.  The CCharge zone is very small, he points out, and our atmosphere somewhat fluid: the air in London blows around and mixes, so even with sufficient data, this study design is not an optimal way to answer questions about the CCharge.* **

All of these limitations in study design and data quantity are reflected in the Health Review Committee’s short commentary on the report:

Ultimately, the Review Committee concluded that the investigators, despite their considerable effort to study the impact of the London CCS, were unable to demonstrate a clear effect of the CCS either on individual air pollutant concentrations or on the oxidative potential of PM10. The investigators’ conclusion that the primary and exploratory analyses collectively indicate a weak effect of the CCS on air quality should be viewed cautiously. The results were not always consistent and the uncertainties surrounding them were not always clearly presented, making it difficult to reach definitive conclusions.

Which is to say: the research so far isn’t really capable of answering any questions satisfactorily.  While the evidence is for a small improvement in air quality thanks to the CCharge, none of the evidence is very good.  They go on to make the academic’s favourite conclusion: more research is necessary.

That’s right, this is a 121 page research review with associated commentary which simply concludes that the existing data is insufficient to tell us anything useful at all.  That’s no criticism of Kelly or the HEI.  They set out to review the evidence; the evidence just happens to be severely limited.

The Health Effects Institute decided to press release this.  “Study finds little evidence of air quality improvements from London congestion charging scheme,” the press release screams in bold caps.  “Pollution not improved by C-Charge,” says Londonist. Can you spot the difference between the HEI press release and the Londonist headline?

There is an old saying that absence of evidence is not evidence of absence.***  It’s a classic source of bad science and bad journalism, and in this case it nicely sums up what is wrong with the Londonist piece.  A review which actually found very weak evidence that the CCharge improved air quality is covered as a study which found hard proof of the exact opposite.

* Indeed, Boris Johnson would like to blame all of the city’s problems on clouds blowing in from the continent rather than the motor vehicles that account for most of it.

** I could add to this limitation the fact that the CCharge was not merely meant to cut car use within the zone: it was meant to fund a massive increase in bus frequencies, subsidise fares, and generally make buses and trains more inviting throughout London.  The effect of the CCharge on road traffic throughout the capital is complex, so it’s questionable whether the “control” sites can be said to be unaffected by the intervention.

*** Before someone points it out, yes I know it’s a bit more complicated than that, but in this case the saying applies nicely.