Air Pollution on the Underground Worse Than Above Ground

The latest report from COMEAP (the Committee on the Medical Effects of Air Pollutants) shows that travelling on the London Underground may be dangerous to your health.

The air in the London Underground infrastructure is high in PM (particulates, i.e. fine dust). This is because of the generation of dust caused by the friction action of train brakes on wheels and wheels on rails, combined with dust generated by the clothes, hair and skin of the millions of people, in close proximity to each other, using the system. One hour on the underground, a typical exposure time for commuters, is equivalent to standing on one of the busiest London roads for the whole day. The deepest underground lines such as the Northern Line are apparently a particular problem.

This problem has been known about for many years – for example the Institute of Occupational Health reported on the problem in 2003 but very little has been done about it since. Cleaning of some stations and tunnels was tried in 2017 but it was shown that cleaning stations alone had little effect and the exercise seems not to have been repeated.

Little research seems to have been done on the impact of underground workers such as train drivers, although there are filters in drivers cabs which might assist.

Another issue is that the composition of underground dust is somewhat different with high levels of metals such as iron compounds and it is not known if that makes it better or worse in terms of health impacts. The COMEAP paper reports conflicting evidence on that issue. As a result although they conclude there is likely to be some health risk they are unable to quantify it. They encourage TfL to undertake more measurements and more studies on this problem.

Comment: I suggest the Mayor of London imposes a new tax on underground trains to tackle this problem as he has done on road vehicles. Indeed he should probably tax underground passengers to encourage them to walk and cycle instead – you know it will be good for you!

But as the Mayor and TfL run the underground and would have to suffer the taxes, don’t expect this to happen anytime soon.

For the COMEAP report in full, go here: https://tinyurl.com/y7phkqyy

Roger Lawson

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Life Expectancy Data Says There Is No Air Pollution Health Crisis

There have been many scare stories published about how air pollution in London and other major cities is shortening lives. London Mayor Sadiq Khan certainly believes there is a major public health crisis that he needs to tackle by aggressive measures against vehicle owners. But data published by the Office of National Statistics simply contradicts these claims.

If such claims were true, one would expect to see shorter life spans for people living in those parts of the country where air pollution was known to be bad. For example some of the central London boroughs such as Camden, Westminster and Kensington & Fulham. But in fact the opposite is true. Residents of those boroughs have longer life expectancies than most of the rest of London, or the rest of the country. The Daily Mail has published an article that covers this subject in depth and even suggests that rather than retiring to the country, you can live longer if you move to central London – see link below.

Women born in the London Borough of Camden have the highest life expectancy overall at 86.5 years, with Kensington & Chelsea at 86.2 years. That’s longer than women who live in the outer London borough of Bromley at 85.3 years. Males live somewhat shorter lives but there is a similar advantage to living in the more polluted boroughs.

London as a whole has a life expectancy of 84.3 years for women and 80.5 years for men and expectancy has been rising until very recently – see ONS statistics link below. That compares with 84.0 years and 80.6 years for the wider south-east of the country. Both London and the wider south-east are much better than all other UK regions apart from the south-west. For example, in the north-east the figures are only 81.6 years for women and 77.9 years for men, perhaps negatively affected by working in former heavy industries in that region.

The Daily Mail article contains a useful interactive map so you can see what the figures are for where you live.

Now there are clearly other influences at work on life expectancy such as the quality of local healthcare and the wealth of the local population (wealthier people are known to live longer) but this data demonstrates that air pollution has no measurable impact on life expectancy at current levels even in the most polluted London boroughs. If it did one would expect to see this revealed in the data recently published by the ONS.

London Mayor Sadiq Khan’s Ultra Low Emission Zone is more about raising taxes on long-suffering vehicle owners than improving the life expectancy of the population.

Daily Mail article: https://www.dailymail.co.uk/health/article-6487389/Women-Camden-longest-lives-UK.html

Office of National Statistics Life Expectancy Data: https://tinyurl.com/n6gls4t

Roger Lawson

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Air Quality and Vehicles – The Truth

The Alliance of British Drivers (ABD) has been very concerned of late with the misinformation that has been spread by the national media about the impact of air pollution from vehicles on the health of the population. We believe it is not a major health crisis but simply a major health scare fed to a gullible public by a few politicians and by journalists wanting a story.

The promotion of such stories has also led to Government over-reaction and a number of local councils proposing “Clean Air Zone” schemes aimed at restricting some vehicles from entering some roads, or charging them extra to do so in the name of reducing pollution. London is in the forefront of charging drivers using pollution as an excuse (e.g. from the ULEZ), but many other cities are planning similar schemes.

The prime objective often appears to be simply the desire to extract money from car drivers and other vehicle users.

The ABD has now published a full analysis of the issues that actually gives the truth about the claims made for air pollution, and rebuts many of the allegations. It can be downloaded from here: https://www.freedomfordrivers.org/Air-Quality-and-Vehicles-The-Truth.pdf

Is there actually a public health crisis? The simple answer is NO. The evidence does not support such claims.

In reality air quality has been steadily improving and will continue to do so from technical improvements to vehicles. Meanwhile life expectancy has been increasing. There is no public health crisis!

Life expectancy might be improved slightly, for example by a few days if all air pollution was removed. But air pollution does not just come from vehicles but from many other sources of human activity such as heating, industrial processes, farming, building, cooking and domestic wood burners. Only about 50% comes from transport. The air outside is typically cleaner than in people’s own homes or in offices and that is where they spend most of the time.

Removing all air pollution would be economically very expensive and leave us with no transport (buses, trains, aeroplanes or cars) and also stop all deliveries of food and other goods. You would not want to live in such a world.

We give all the evidence on our claims above in the aforementioned paper.

But the ABD does accept that air pollution does need to be improved, particularly in certain locations, and we recognise public concern about it. However we argue that measures taken to improve matters should be proportionate and cost effective. There needs to be a proper cost/benefit analysis before imposing restrictions or charges.

There are many measures that can be used to reduce vehicle emissions without restricting motorists or imposing major extra costs on them.

There is certainly no need to panic over air pollution!

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More on Air Pollution from the BBC and Closure of Beech Street

The latest piece of air pollution propaganda from the BBC was a television report that air pollution may affect your brain. This was based on a recently published Chinese study that long-term exposure to air pollution “could be linked to cognitive performance” (see https://www.bbc.co.uk/news/health-45326598 for the written version of the BBC’s report).

As is common with air pollution studies, this is based on an epidemiological study that showed that people who have lived in heavily polluted areas for a long time show less cognitive function on simple tests of math and verbal skills. It also suggests that there are differences in the impact between sex, age and education of the study participants which seems unexpected but they explain that as being affecting mostly men who have worked outside for long periods. The study was done in China where air pollution is of course a serious problem – for example Beijing has much worse air pollution that western cities such as London. The paper was published by the US National Academy of Sciences.

There is of course no evidence linking the possible causes to the effect and it could simply be that the selected participants suffer from the work they did, or the lack of mental exercise they took (cognitive functions decline if not used).

In summary, the scientific paper is just that and it is wrong to extrapolate it to suggest people in London or other cities are likely to be affected. Or is the report explained by BBC reporters spending too much time standing on College Green near Parliament Square, where they like to do interviews, and breathing in too much hot air? It certainly seems to be the case that talking about air pollution too much damages your brain.

Beech Street Closure

The City of London Corporation is still keen to tackle the problem of air pollution in Beech Street – this is the road that runs underneath the Barbican in a tunnel and is a key east-west route within the City. The only other alternative routes are via Old Street or City Wall which are both heavily congested. But Beech Street is one of the most heavily polluted roads in London for NOX emissions.

There are several options being considered. That includes restricting the road to Ultra Low Emission Vehicles (ULEV) only, closing the road in both directions (but leaving access to the Barbican car parks) or just closing in the East-West or West-East directions. Traffic modelling of the possible closures is being considered but it would require building a large new model of traffic flows.

But the impact of a full closure is already known because in March 2018 the road was closed for 5 days. Average journey times on the roads north and south of Beech Street increased by 23%.

The report on this subject which is being considered by Corporation Committees in early September notes the likely objections from many City business and residents to any closure though.

Comment: It would be unfortunate if yet another key road in the City is closed to traffic. The road network in the City of London has been degraded substantially in recent years by road closures such as that of Bank Junction. Could the air pollution in Beech Street not be tackled by a forced ventilation system? But there is no mention of that being considered in the Corporation’s report.

Roger Lawson

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Fighting For Air – Another Piece of Air Pollution Propaganda from the BBC

Last night the BBC broadcast a programme on air pollution entitled Fighting for Air (BBC2 on 19/8/2018). It was presented by Dr. Xand van Tulleken in a populist and dramatic style.

He first did a simple test by “cleansing” his system by donning a chemical weapons suit followed by 3 hours of deliberately breathing in traffic fumes. He did blood pressure tests, analysed blood composition and checked for brain function before and after. This unscientific and uncontrolled test apparently showed a slight increase in blood pressure and blood clotting and possibly a very small change in cognitive function. No actual data was given. Bearing in mind that such tests as blood pressure can vary significantly from hour to hour, and the other tests likewise, this proves nothing at all. Note that there have been a number of scientific studies of a possible link between blood coagulation and air pollution but no clear conclusions about which pollutants are relevant and no specific link to heart disease or stroke risk identified. That did not stop Dr van Tulleken alleging such a link.

He then moved to Kings Heath High Street near Birmingham. This road exceeds national legal limits for NOX apparently by a small amount at some times. It is used by a large number of diesel buses (no hybrids or electrics), and by significant numbers of HGVs. Traffic is stop/start with high congestion because of traffic lights that are not linked and road side parking as people move in and out of the parking spaces.

Dr van Tulleken persuaded the local council to suspend the parking bays for a day (filled with bay trees instead) and to synchronise the traffic flights to provide a “green wave” and he also persuaded the bus company to offer free tickets. The result was the volume of traffic remained the same, but NO2 fell by 10%. It is not clear to what extent any adjustment was made for other factors such as weather changes although mention was made that the changes were measured against wider area changes.

Local shopkeepers were not happy particularly a butcher who had traded in the road for 50 years.

Comment: In summary all this programme showed is that smoothing traffic flows may significantly reduce some emissions from vehicles. We already knew that, for example from studies of speed hump schemes. Replacing road side parking by off-street parking is clearly something that councils should look at. I only wish that removing such parking be done in my local High Street (Chislehurst in the London Borough of Bromley) which has been proposed in the past but never progressed (there is already plenty of off-street parking). It would both reduce the air pollution and reduce congestion by improving the flow of traffic.

What the programme did not demonstrate was that air pollution is a major health hazard or a public health emergency as the Doctor disclaimed. Indeed the High Street Butcher demonstrated how much cleaner his shop is than it used to be suggesting particulate emissions were lower than a few years ago.

In conclusion, another disappointing and hysterical programme on air pollution rather than a truly balanced study of the issues.

Roger Lawson

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Do Low Levels of Air Pollution Damage Your Heart?

Following the publication of a scientific paper analysing heart condition and the impact of air pollution, the national media immediately jumped to headlines such as “Low Levels of Air Pollution Linked to Changes in the Heart” as published by the BBC. Stories were typically illustrated with pictures of traffic jams, car exhaust and visible London air pollution. Calls to reduce legal maximum air pollution figures were added.

What does this scientific paper actually show? You can read it here: https://www.ahajournals.org/doi/pdf/10.1161/CIRCULATIONAHA.118.034856 . It’s a paper by Nay Aung et al. But here are some comments on it:

  1. The paper was published in the journal “Circulation”, a small distribution specialist scientific journal, It is based on information from the UK Biobank which contains medical information on thousands of volunteers who have in this case had heart scans.
  2. The study correlated the information from 3,920 individuals to air pollution data (specifically NO2 and PM2.5) where they lived from 2005-2010.
  3. The study concluded that after adjusting for numerous other factors such as demographics (age, sex, ethnicity), anthropometrics (height, body mass), socioeconomic factors (income, employment, educational status), cardiac risk factors and physical activity there was a positive correlation between minor changes to left ventricle (LV) mass and other heart changes to air pollution levels where the volunteers were resident.
  4. Such changes to a heart are known to precede heart disease.
  5. The paper’s authors therefore concluded that “our findings add to the growing evidence of the damaging effects of ambient air pollution even in the setting of relatively low exposure levels”.

Are their conclusions justified beyond any doubt, and in particular are the popular media’s headlines justified? My conclusion is no. For example, like any epidemiological study it only provides a possible statistical association, not a direct cause. As Prof Kevin McConway commented on this paper (as reported by the BBC): “Heart disease is affected by a wide range of factors – smoking, drinking alcohol, diet, exercise, social position, and more. Suppose that people whose heart health is worse because of some of these factors are also more likely to live in places where air pollution is high. That could show up as a correlation between air pollution and heart disease, even if the pollution itself is having no direct effect on the heart”.

Another possible issue is that air pollution inside houses is known to often be many times worse than that in the most polluted streets. That pollution comes from cooking, new paint, fabrics, carpets, smoking by other residents, animal hair, etc. Lack of ventilation in houses and apartments can increase levels substantially so people who live close to noisy roads who never open their windows as a result may be particularly affected.

The report is open to attack on the detail of their statistical methods, and they also note that other similar studies did not provide the same evidence in all cases. In summary the overall evidence is quite weak. Neither does the report confirm that the minor changes noted to heart mass lead in this case to significant heart disease.

Their reference to “low exposure levels” may also be misleading because air pollution levels were not measured outside the volunteers’ houses or where they work. In addition the fact that the people studied were volunteers, i.e. were self-selected rather than being a randomised sample, could have biased the outcome even though lots of adjustments were made for possible confounding factors.

All the report really suggests is that more study should be undertaken of a possible effect. The conclusion drawn by some commentators that air pollution legal limits need to be reduced further is not substantiated by this report.

In the meantime, readers are advised not to live within a few metres of a busy road because it may be bad for your health. But that’s no surprise is it? Just living in a noisy environment is known to be very damaging to your health. High noise levels are correlated with cardiovascular disease according to the World Health Organisation. It seems it increases stress levels which has a negative impact on health.

What the Aung report does not do is justify even more aggressive attempts to reduce air pollution in cities such as London, where NOX and particulates are already falling after the mistaken support of more diesel vehicles by the Government. Road vehicles will soon no longer be a major contributor to air pollution in cities so more scaremongering of this ilk is not required.

The answer to the question posed in the headline of this article (“Do Low Levels of Air Pollution Damage Your Heart”) is simply that it is “Not proven”.

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Who Is Responsible for Excessive Urban Vehicle Emissions?

Is it the vehicle manufacturers, or people buying cars and vans without thinking? The ABD has recently issued a press release on this topic which lays the blame firmly on Government. See http://www.abd.org.uk/government-entirely-responsible-for-urban-vehicle-emissions-issues/ . In London that means the Mayor of London supported by TfL, plus the local London boroughs.

In summary vehicle emissions have improved enormously in the last few years, but those improvements have been defeated by unwise policies for tackling traffic congestion. Traffic speeds have slowed, which increases pollution. The ABD suggests in our press release how pollution could be tackled with more sensible policies.

Roger Lawson

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