We are familiar with claims that air pollution (cue pictures of diesel cars!) is killing thousands of people every year in the UK.
I have been trying to get hold of the actual mortality statistics, but fortunately came across a study carried out by the British Lung Foundation.
Finished last year, it analyses death rates between 2008 and 2012.
This is the key table:
The Report notes:
Over half of the deaths from lung disease in the UK are due to lung cancer and COPD. Both conditions are strongly linked to tobacco smoking, which is also a risk factor for pneumonia, another leading cause of death.
Taking lung cancer and COPD out of the equation, we are left with 49030 deaths from other causes. Of these pneumonia accounts for 28952, and as the Report states, smoking is also a risk factor for that.
Pneumonia is not caused directly by air pollution and is usually a viral infection. Some groups have an increased risk of developing pneumonia, including smokers, people with other health conditions, and those with a weakened immune system, for example following a bout of flu.
What is clear is that there is very little evidence to claim that some cases of pneumonia are caused by air pollution.
Most of the other causes can be ruled out for any connection with air pollution, including lung diseases due to external agents (usually coal dust, asbestos, silicon dust etc), pleural mesothelioma, pulmonary embolism, bronchiectasis, pulmonary vascular diseases, TB, sarcoidosis, perinatal conditions, cystic fibrosis, and influenza.
In fact, it just leaves us with:
|Acute Lower Respiratory Infections||1589|
|Acute Respiratory Failure||127|
A total of 2962.
According to the NHS:
Asthma is caused by inflammation (swelling) of the breathing tubes that carry air in and out of the lungs.
This inflammation makes the breathing tubes highly sensitive, so they temporarily become narrow. This may occur randomly or after exposure to a trigger. The tubes may also sometimes become clogged with sticky mucus.
Common asthma triggers include:
- allergens, such as house dust mites, animal fur, and pollens
- other irritants, such as cigarette smoke, strong smells, gases and
- chest infections
The reason why some people develop asthma isn’t fully understood, although it’s known that you’re more likely to develop it if you have a close relative with the condition.
Clearly, we don’t know everything about asthma, but there is little evidence to suggest that air pollution from traffic makes much difference.
The other two causes on the list are, of course, merely catch alls.
COPD, or Chronic obstructive pulmonary disease, includes emphysema and chronic bronchitis. According to the NHS:
Smoking is the main cause of COPD and is thought to be responsible for around 9 in every 10 cases. Exposure to certain types of dust and chemicals at work may damage the lungs and increase your risk of COPD.
Exposure to air pollution over a long period can affect how well the lungs work and some research has suggested it could increase your risk of COPD.
But at the moment the link between air pollution and COPD isn’t conclusive and research is continuing.
As for lung cancer, Public Health England state:
And according to the NHS:
Smoking cigarettes is the single biggest risk factor for lung cancer. It’s responsible for more than 85% of all cases.
If you don’t smoke, frequent exposure to other people’s tobacco smoke (passive smoking) can increase your risk of developing lung cancer.
Radon is estimated to be responsible for about 3% of all lung cancer deaths in England
Exposure to certain chemicals and substances used in several occupations and industries has been linked to a slightly higher risk of developing lung cancer.
While some studies link diesel fumes to lung cancer, the actual numbers indicate that if there is any effect it is a very small one.
There were 35419 deaths from lung cancer in 2012, Even if a small proportion of these were linked to air pollution, the total number of deaths, including the other respiratory diseases, would be much smaller than the 40000 estimated.
It has also been claimed that air pollution can exacerbate heart conditions, but with so many factors contributing to heart disease, any attempt to claim that a certain number are due to air pollution is dishonest.
The claim that 40000 deaths are linked to air pollution is not supported by the facts, or for that matter any figure close to it.
Deaths by Age Group
But it gets even worse.
Let’s look at deaths by age group:
The vast majority of deaths from lung disease, 88%, are in the over-65 group. Indeed most of these are actually over 75s.
It is a sad fact that we all have to die of something. And when medicine has kept us alive into our 70s and 80s, it is often our respiratory systems that pack up first. There does not have to be an external reason for it.
In fact, in some ways, we could argue that these are not “premature deaths” at all, but that people have lived longer than “normal”.
But more importantly, older people will have been exposed to all sorts of air pollution, both indoors and outdoors, throughout their lives. Most of this pollution must have been many times greater and toxic than anything people are experiencing nowadays.
So, even if there really are 40,000 premature deaths a year, they have occurred because of the cumulative effect of inhaling real pollution for decades, and not as a result of current levels of pollution.
The Lung Foundation show this chart for the relative risk of dying. (The scale is from 0.6 to 1.9, so there is roughly three times the risk of death in the worst areas than the best.
Relative risk of death from any lung disease, by local authority district (England, Scotland and Wales), 2008–12
As would be expected, the risk is much greater (dark areas) in the industrial heartlands of the North West, Yorkshire, Tyneside and Scotland.
In contrast, London barely figures at all.
Yet, when we compare with this map which appears on the BBC report (linked above), we get a completely different picture:
Although the BBC version is only for PMs, there is no correlation at all with the actual death statistics. According to it, about 8% of adult deaths in London are due to PMs alone, never mind other pollutants.
If this figure was applied nationally, it would imply a total death from PMs of 45,000, more than a third of the total deaths from all types of lung disease. We have already seen that the vast majority of deaths from lung disease are related to smoking.
Quite simply, the numbers simply don’t stack up.
The BBC article was based on a Report published last year by the Royal College of Physicians (RCP) – “Every breath we take: the lifelong impact of air pollution”
The RCP report did not undertake any research of its own, nor commission any. Instead, it has merely taken evidence from previous studies.
There are many junk studies from which they could have cherry-picked any answers they wanted.
The whole report is clearly written around a political agenda, with very few hard facts presented. (To get a feel for this, check out the 20-page summary, full of silly cartoons and scary headlines).
A clue to why this should so appears in the Background, on Page 120 of the report:
The original objective was to investigate the health effects of climate change. Realizing this was likely to be a dead duck, what better than to raise the specter of air pollution?
Read more at Not a lot of People Know That