Air quality and health – a few thoughts now the dust has settled

Last week a cloud of Saharan dust swept across the UK, and as a result stories about air quality settled with similar ubiquity across the country’s media. As soon as we could see the choking cloud in front of our faces, we all wanted to talk about a problem that has in fact been with us every day for decades. No metaphor could have made the point more clearly that ‘out of sight is out of mind’.

Woman coughingJust last week, the World Health Organisation (with perfect timing) released new data suggesting that one-in-eight deaths around the world can be linked to air pollution. There’s no need for me to re-hash arguments made very well in the better quality media last week (see John Vidal’s piece in the Guardian, ref below). The one thing I’d like to pick up on is just what all those people in the WHO data are dying of, and perhaps why we and our politicians seem incapable of seeing the problem except when it paints the streets red.

The media reports during an air pollution ‘episode’ like the one we just had invariably focus on coughing, asthma, stinging eyes – the sort of thing you’d expect. I saw one paramedic interviewed on the BBC saying, ‘Yes, we’ve seen a 14% rise in cases of acute respiratory illness over the last two days.’

The thing is, if you read the WHO report, it summarises the deaths linked to outside air pollution by cause, and this is the run-down:

  • 40% – ischaemic heart disease;
  • 40% – stroke;
  • 11% – chronic obstructive pulmonary disease (COPD);
  • 6% – lung cancer; and
  • 3% – acute lower respiratory infections in children.

That’s 80% caused by heart disease and stroke, before you get to the ‘obvious’ stuff, the ‘lung’ stuff. I’ll be honest and admit that it made me sit back and think. So I went looking for a little more explanation, and found some great references from the American Heart Association (hardly radical) and then the penny dropped, because they reference the many studies on second-hand cigarette smoke.

We all know smoking is bad for us, and we know that it massively increases the risk of heart disease and stroke, two of our society’s biggest killers. And we’ve enacted smoking bans in public places because we realised that inhaling smoke puts you at risk even if you’re not a smoker.

Step out onto the street in London, and the air may not be pleasant, but you’re not immediately thinking about people dying from it. You may well know someone with breathing problems, or asthma, but they probably manage it. But I’m guessing most of us have been touched by the death of a friend or relative from stroke or heart disease, and not necessarily a smoker. Was the air they were breathing the final straw? Quite possibly.

Our current controls on smoking have taken decades to enact, and smoking is regarded as much more of a choice than the presence of buses, trucks, taxis and cars on our streets. In the case of smoking, it took a culture change – the public had to internalise the evidence of health risk, and the politicians reacted (eventually) to that change, some of the braver ones even helped it along.

Action is being taken on air quality, but much too slowly (another post on that soon). If we want a quicker pace of change, I think one component will need to be a greater recognition of the true health impacts, and just how much the invisible cloud is affecting us, our friends and our relatives.

So here’s a thought – next time you step outside in a major city, look at the traffic and picture every exhaust pipe as a giant cigarette. I’m talking about a six-foot Gauloises, smoked by an elephant with a 200-a-day chain-smoking habit. See if that changes your perspective on air quality.


WHO press release:

John Vidal’s piece in the Guardian:

Information from the American Heart Association:


3 thoughts on “Air quality and health – a few thoughts now the dust has settled

  1. Fantastic post Dom and much anticipated!

    What I would love to know — and I realise you aren’t operating a blog-by-request service — is what proportion of the polluted air (during a normal data, or at least not in the midst of an aberrant Saharan wind) is down to good-ole fossil-fuelled road vehicles? And of that, what is the proportion attributable to good-ole one-person-per-vehicle transportation choice?

  2. That’s a fair question Scott, and I’ll add it to my list of possible blog topics for a more thorough answer in future. However, the short answer is, if you’re in an urban area, the vast majority of particulates and NOx are from vehicles. As for the proportion from cars, that went down as we cleaned up our petrol cars, but is rising steadily again due to the European preference for diesel cars (now over 50% of cars sold).

  3. Nice post Dom. I also make the tobacco control analogy when teaching my students about air pollution and health policy. It took us 50+ years of science to get serious about smoking control, and that’s for a very simple exposure-outcome thing to measure really (nearly everyone who gets lung cancer has smoking as a causal factor). When we have something that’s actually a way more complex relationship – different aspects of air quality and various health outcomes – and equally affected by substantial vested interests, it’s not actually that surprising that we’re not doing much about it. Even though the science now is pretty darn convincing – although as with smoking, we’ll never get evidence from a randomised controlled trial..
    If you haven’t come across it, this is the go-to (government advisory) source on this issue in the UK:

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