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The effects of particulate pollution have recently been in the news. In the UK the Daily Mail reported:

Toxins emitted by Britain’s booming number of diesel cars are fuelling a health crisis that kills 40,000 people a year, a landmark report warns today.

Ownership of diesel cars has more than trebled in the past 15 years – driven by misguided government tax incentives that identified diesel as a ‘green’ fuel.

Today’s report by the Royal College of Physicians and the Royal College of Paediatrics and Child Health warns that the health impact of Britain’s air pollution is greater than previously thought. It calculates that 40,000 people in Britain die early each year because of outdoor air pollution, a significant increase on the previous estimate of 29,000.

The estimates are UK specific but the problem is worldwide and caused, allegedly, by the small particulates in vehicle emissions (especially diesel vehicles). The culprits appear to be PM10s and PM2.5s which are categories of small particulate matter grouped by their size.

This is a large number of deaths. In the UK it would be between 5% and 10% of all deaths. If the estimates are correct other countries with lots of vehicles will also have many deaths.

So are the estimates correct? Are large numbers of people in the developed world dying from particulate air pollution?

NB air pollution worldwide is estimated to kill millions but most of this is caused indoors by wood and dung-burning fires. This question is specifically related to outdoor pollution caused by vehicle emissions.

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matt_black
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  • Suggest you remove the reference to "outdoor air" since, unless you're in a building with a fairly sophisticated air filtration system, the indoor air is exactly the same as the outdoor air. – jamesqf Feb 20 '17 at 19:13
  • @James What is your reasoning for that? How about a source? My knowledge of the subject indicates that in developed countries indoor air is often very different from outdoor air. –  Feb 20 '17 at 19:40
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    @jamesqf I don't want people to get distracted by what is essentially a third world problem. Besides, indoor air *isn't* the same as outdoor air especially with particulates. – matt_black Feb 20 '17 at 20:17
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    @fredsbend: The source is simple logic. Where does the air inside the buildings come from, if not the outside? Unless there's some sort of particulate-removing filter in the ventilation system, everything in the outdoor air will come inside. Not to mention that in most of the temperate world, windows are opened most of the year, so there's no ventilation system involved. – jamesqf Feb 20 '17 at 22:20
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    @James Nope. You may be thinking logically but you haven't considered everything. *"In the last several years, a growing body of scientific evidence has indicated that the air within homes and other buildings can be more seriously polluted than the outdoor air".* [EPA](https://www.epa.gov/indoor-air-quality-iaq/inside-story-guide-indoor-air-quality) –  Feb 20 '17 at 22:45
  • @jamesqf Logic isn't a good way to work out what really happens to the concentration of particulates (or reactive chemicals) in air. In reality the concentrations vary spatially and may be heavily attenuated indoors. Things are not evenly distributed as normal atmospheric gases would be. – matt_black Feb 20 '17 at 23:14
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    This probably isn't what you're looking for, but "Daily Mail reported" should probably be a red flag... – apaul Feb 21 '17 at 00:24
  • Common sense is not "logic" @jamesqf, make sure not to mix them up :-) – Sklivvz Feb 21 '17 at 00:42
  • @apaul34208 Normally I'd agree with the red flag for the daily mail. But in this case many other (more reputable) sources also reported it. I only picked the daily mail as the Guardian quote was less clean in how it reported its source. The BBC reported the same story with roughly the same conclusions. – matt_black Feb 21 '17 at 01:04
  • @fredsbend: Certainly indoor air could be MORE polluted, if for instance you close all the windows and doors, and invite a smoker or two. What I'm saying is that without filtration, it can't be LESS. (Over time, of course: you might e.g. close the windows & doors when smoke from a wildfire is blowing in, but given a few hourse it will seep in. – jamesqf Feb 21 '17 at 05:11
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    Attributing a given, non-violent death to any specific cause can be quite tricky. If someone dies of lung cancer, was the "cause" the polluted air in his home town due to the coal power plant there, his regular car commute to work two towns away, or that one time he received a high radiation dose? All we know is that he died of lung cancer. Depending on agenda, people will point to other contributing factors or generally say "we don't know" to absolve whatever they think isn't so bad of blame. – DevSolar Feb 21 '17 at 08:57
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    @jamesqf Indoor air can be very different even without explicit filtration. Take particulates in air as an example. Particulates are deposited on any surface over which the air flows. This generates dirty patterns around leaky windows and air vents as the particulate content hits surfaces and sticks. So not all the particulates in the incoming air reach the internal atmosphere. – matt_black Feb 22 '17 at 09:54

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Seems to be a case of cherry picking... A study was done by the Royal College of Physicians and the Royal College of Paediatrics and Child Health, the BBC picked up the story, the NHS ran with the story, and then the Daily mail cherry picked a conclusion.

From the NHS:

"Air pollution is contributing to about 40,000 early deaths a year in the UK," BBC News reports.

That's what the NHS said, and they went on to recommend:

Promote alternative transport to cars fuelled by petrol and diesel; this may be walking, cycling, and use of public transport or electric/hybrid cars.

Note this is the only use of the word diesel in their report on the study.

The original article as posted by The Royal College of Physicians does not contain the word "diesel" although the pdf download does site diesel as a contributing factor.

The 40,000 figure seems to come from the pdf:

Each year in the UK, around 40,000 deaths are attributable to exposure to outdoor air pollution, with more linked also to exposure to indoor pollutants.

and:

Each year, inhaling particulates causes around 29,000 deaths in the UK, which, on recent evidence, may rise to around 40,000 deaths when also considering nitrogen dioxide exposure.

To get to the point...

The Daily Mail seems to have fallen into a bad case of single causation. Yes the report states that:

Nitrogen dioxide and particulates from diesel engines have been poorly controlled and these remain a problem. In the UK today, about half of cars run on diesel. This is the trend across Europe...

But it also states that:

Growth in pollution has not always been as fast as growth in traffic, thanks to tighter exhaust controls. Modern cars produce very little carbon monoxide and hydrocarbons, and the sulphur and lead in diesel and petrol must meet tight regulations.

To sum it up...

Yes inhaled pollution is bad, and some of that can be attributed to diesel transport, and more could be done to regulate diesel engines to help with that, but it certainly isn't the sole cause of 40,000 deaths per year in the UK. More or less, as far as diesel is concerned, it's better than it used to be, but there's still room for improvement.

apaul
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    As i understand it, the OP's question isn't so much about whether it's Diesel or something else that causes the pollution, but if the number of victims (40k) is correct in order of magnitude and probably about how this number is obtained. – Scrontch Feb 21 '17 at 08:26
  • @scrontch from what I could gather from the report the figure seems fuzzy at best. Looks like they gathered figures from deaths that could be related to air pollution, but obviously some asthma and cardiac events can't be directly attributed without extensive case by case investigation... And they obviously couldn't possibly do that level of investigation on every one of the claimed 40,000 cases... So I focused on the Daily Mail claims because I didn't have the time or forensic expertise to examine all of the deaths either... Though I would guess that air pollution was a contributing factor. – apaul Feb 22 '17 at 00:20