Many journals have pronounced that London’s ‘filthy air’ is killing thousands, and we note that all candidates standing for Mayor of London this year quote Air Quality as a pillar of their campaign. Here, taking the long view, we look more closely at the claims and wider issues, and how they apply to Hammersmith, public transport and cycleways. 

According to King’s College, the reference for air quality measurements, London is the 2,516th most polluted city in the world

We think that climate change is the key issue here, and which if properly addressed, would deal with many of today’s air quality issues. The reference work ‘Mortality Effects of Long-Term Exposure to Particulate Air Pollution in the United Kingdom’ (A report by the Committee on the Medical Effects of Air Pollutants [COMEAP], updated 2018), says clearly in its executive summary ‘As everyone dies eventually no lives are ever saved by reducing environmental exposures – deaths are delayed resulting in increased life expectancy.’

Air quality in London started deteriorating about 400 years ago, and for the entire time the Georgians and Victorians were painting the globe pink, sulphur dioxide was around 40 times the current WHO guideline level of 20 µg/m³. It was in fact raining sulphuric acid AKA ‘acid rain’, the effects of which can be seen on the Palace of Westminster or in Turner’s paintings.  The Great Smog of 1952 that killed perhaps 12,000 appears as a peak on the graph, and created a level over 10 times the level it is now, but our nonagenarian, and in one case centenarian parents survived and are still here with us, begging the question what effect it had on long term life expectancy.

The answer from COMEAP is around six months if you could (unrealistically) remove 100% of all air pollution from all sources, or more realistically 20 days per µg/m³ removed, plus you have to live to those grand old ages otherwise healthy.  Not as much as the headlines or Twitterati would have it.

Of course this isn’t a complete list of pollutants, there’s PM2.5, PM10, NO₂, and Ozone which have differing WHO thresholds as shown here, and those with respiratory conditions are much more affected than others, explaining most of the 1952 deaths.

London Air quality history, 2010-2019

Broadly, having exported almost all our heavy industry and its consequent pollution to the Far East or Eastern Europe, and replaced the acid rain by some nitrogen oxides, we live in the cleanest air since Shakespeare. In summer 2019 all 3 key indicators simultaneously dipped below WHO guidelines, as shown here. 

We might rightly be ashamed that we’ve exported our problem to the rest of the World, but that’s a different matter – when addressing the questions of both Climate Change and Air Quality, we are forced to confront the reality that it is likely that the luxury of warm homes and safer transport brought about by burning all that fossil fuel that has gone a long way in supporting our unprecedented life expectancies. 

UK domestic energy consumption [UK
housing energy fact file 2013 – latest available]

One can readily make the case that all household energy efficiency improvements over recent decades have been eaten up by higher average indoor temperatures, allowing glossy photos of people walking around in shorts and T-shirts in winter in their ‘luxury apartments’. According to the Building Research Establishment, in 1970, the average internal temperature of a home in the UK in the winter months was 12°C.  It now exceeds the healthier WHO guideline of 18°C, but often at a large carbon cost.  The fact is that domestic energy use has been rising for 50 years or more, though its sources have become greener in recent years. 

Unfortunately, a similar case can be made against modern “gas-guzzling” SUV’s, or even modern versions of classics like the Golf that compensate in weight and/or size for the increased fuel efficiencies provided by improved technology, engineering and standards, highlighted in this 20 year old New Scientist article, and shown to be continuing in this much more recent article. Sadly the current Battery-EV versions of these cars are the heaviest of them all.

Which pollutants are most important ?  It’s unclear because the individual tests that have been done don’t correlate the different types and their relationship – it would be very hard to separate them out.  But PM2.5/PM10, said to be some of the most problematic, are related to particulates, especially from diesels, which are reducing gradually with new emissions controls (e.g. Euro 6, 2014), and will reduce further with more electric vehicles (EV’s).  So much so, that a recent survey of European research shows that the particulates from brakes and tyres (yes EV’s have them too!), are now of approximately equal level and therefore concern.  Those ever larger SUV’s and heavier EV’s will throw up more.  The industry has mostly been focusing on one type of particulate – which can be scientifically risky.  Of course NO₂ and CO₂ remain an issue.

Closer to the Mayor of London’s bailiwick, and again for some perspective, we need to look at air quality on public transport – London Underground in particular – it’s not good to put it mildly, as recently reported in The Times.  The deep lines would be shut down tomorrow if Mayoral pronouncements about the dangers of particulate air pollution applied equally to TfL, as they do to other people’s pollution – the levels measured by COMEAP are positively Dickensian as reported here by the BBC.  A friend of the Society who owns an EarthSense Zephr says the NO₂ concentrations are several times greater than the legal limit, and we haven’t started on all that brake dust in the tunnels.

PSD’s at Westminster station. Mind the Gap!

In modern metro design, Platform Screen Doors, which can be seen on newer parts of the Jubilee Line, are not there solely to stop people falling onto the tracks as many believe, they are also there to keep all the muck in the tunnels.  The JLE couldn’t afford to do it properly when upgrading older parts of the line – doors can’t and don’t reach the roof – probably because of a lack of adequate tunnel vent systems to relieve the pressure, missing a large part of their raison d’être.

Looking at the rest of the World, starting in Europe, it’s not much fun if you’re living in the East it seems, where there is still substantial heavy industry. We won’t plot India and China, they are off-the-scale bad for the above reasons and many others, giving us more perspective.

European Air quality divide – source: The Economist

According to King’s College, the reference source for air quality measurements, London is the 2,516th most polluted city in the world. There are over 2500 worse cities in which to live, not that that makes you feel any better, but it does give just a little more perspective to the claims of ‘crisis’. As some have said, poverty actually kills a large number of people.

Some places are worse than others fairly obviously. The Euston Road is one of the worst places with regularly over 150µg/m³ NO₂ for short periods alongside Earls Court Road because of the constant traffic and enclosure.

Hammersmith

Hammersmith NO₂ (www.airqualitymatters.uk)

A check of Hammersmith NO₂ levels reveals that the back streets of Hammersmith are below 40µg limit, with the main roads higher, the A4 slightly lower than Fulham Palace Road or The Broadway.  By way of an unexpected example, if the 40µg threshold were moved up 8µg – which given the uncertainty that COMEAP and the WHO assign to their current ‘guideline’ levels – is not scientifically unreasonable, then Talgarth Road would pass.  In today’s binary world, that would be perfect, but falling the other side of the line would be marked ‘toxic’ and fill Twitter – and Mayoral pronouncements – with talk of a ‘crisis’.  The science is more nuanced than that, and as Kings College has recently said, walking and cycling down a back street you are likely to experience half the pollution, and be within WHO guidelines.

This is a key driver for our stance on cycle routes – which should use back streets wherever practicable.

We conclude that roadside air quality – while a current issue – will be mostly addressed in the medium/long term by the inevitable change to hydrogen powered buses, EV’s, more self-propelled means of transport (walking/cycling), and a greater regulation of hitherto largely unregulated world shipping over the coming years. 

The much more important issue of CO₂ emissions and consequent climate change, poverty, particulate pollution on the Underground, or black cabs, mysteriously excluded from ULEZ regulations, should replace ‘London’s filthy air’ at the top of any London Mayoral candidate’s list of campaign issues, because, while transport is an issue, home heating, particularly what many believe to be eco-friendly wood burning stoves, commercial HVAC systems and many other outputs of Londoner’s lives are more significant.