Life of breath: Understanding air pollution and disease through the Arts

Media vita in morte sumus.  Image from You Tube.

I have written on the Life of Breath blog about the symmetry between breathing as life, and breathlessness as death (as it appears in the words of the haka – see ‘I will not be drowned’).  The line media vita in morte sumus (‘in the midst of life we are in death’) was supposedly composed around the end of the first millennium, but is now believed to be a much older phrase, encapsulating a still older idea: that understanding something means encountering and attempting to understand its counterpart (1).  Just as All Hallows and All Saints are separated by nothing more than midnight, life and death cannot be separated from (nor understood without) each other. The Life of Breath project is a five-year senior investigator award funded by the Wellcome Trust (PIs Prof. Havi Carel at the University of Bristol and Prof. Jane Macnaughton at Durham University), considering breathing and its ‘pathological derivative’ breathlessness as two halves of a whole.

This sense of opposing ideas, linked and hinged in the middle, can also be found in some of the causes of breathlessness, such as smoke. Smoke resists definition. It can be dirty, as in Blake’s poem ‘London’ (‘Every black’ning Church appals’) or at the beginning of ‘Paradise Lost’ (‘a pitchy cloud of locusts’); or it can be cleansing, for example when fumigating a building. It can be a tool, to give food flavour and longevity, or to stupefy bees; or it can be a silent killer in a house fire, more dangerous than the fire itself. Smoke can also be holy, as in the veils of smoke and incense that surround God in the Old Testament. Steven Connor speaks of the God encountered in the Old Testament as ‘a smoky God … His ineffability and unapproachability are signified in the cloud of smoke’ that descends on Mount Sinai, and notes the duality I just mentioned, stating that ‘Smoke can be life, spirit, meaning itself; but it is also horror, filth, chaos’(2).  It seems natural, then, that we can find smoke both comforting (smokers may enjoy the smell of cigarette smoke, church-goers the spicy smell and ritual of the thurible) and disturbing: something that causes us to cough or wheeze, or which, over time, permanently compromises our ability to sing, speak or breathe (3).

Nelson’s Column during The Great
Smog, 1952.  Image taken from
geograph.org.uk via Wikipedia

This last is our most pressing concern when we consider smoke discharged directly into the air, whether it is via an exhaust pipe or a chimney (what Connor calls ‘the sewer into the sky’). These ideas are also bound up in historical approaches to breathlessness, respiratory diseases and conditions, and their relationship with smoke and air pollution (4).  A member of the project advisory board, Mark Jackson, notes that, before chronic or seasonal respiratory conditions such as asthma were properly understood, patients were given conflicting advice. Those suffering from hay fever or ‘summer sneezing’ were often told to treat their condition with ‘fresh air’, visiting the coast to inhale the supposedly clean sea breezes (5).  Elsewhere, Jackson tells us that during the Industrial Revolution, asthma sufferers might be given the opposite advice and told to breathe sooty air for its supposedly antibacterial properties (6).  Both Connor and Jackson write about the Great Smog of 1952, which killed several thousand people in the capital through exacerbating or inducing respiratory and cardiac disease. Here we might note another pair (the heart and the lungs) that cannot be easily separated, as we discussed at the first meeting of the core project team (see ‘Taking a deep breath’). Jackson notes that the link between pollution and disease was already well established before the Great Smog, and before the 1956 Clean Air Act it led to (7).  He states that the Act focused on ‘visible’ pollution, specifically prohibiting the emission of ‘dark smoke’, but paid less attention to invisible pollutants such as sulphur oxides and carbon monoxide.

As well as ignoring or dismissing pollutants that we cannot see, perhaps it is a natural human response to look on the vastness of the sky or the ocean, and assume that their sheer size dwarfs anything discharged into those spaces, rendering it dilute and harmless. As suggested by the invisible poisonous gases wafting stealthily around our towns and cities (or, indeed, our supposedly clean countryside and coastline), very often we are oblivious to that which threatens us. However, complacency offers us no protection from the consequences of air pollution, particularly for respiratory health. For example, chronic obstructive pulmonary disease (COPD) is now the fourth most-common cause of death worldwide, but there is no comprehensive history of breathlessness in a clinical context, a lacuna that the Life of Breath project aims to fill. The project will also attempt to situate breathing and breathlessness in their proper context via an interdisciplinary approach that draws on patient experience and clinical practice, as well as other relevant disciplines, such as medical humanities, history, philosophy, literature and anthropology, using each area to inform the others.

The funeral sentences in the Book of Common Prayer include the line ‘in the midst of life we are in death’. They go on, ‘Thou knowest, Lord, the secrets of our hearts’. As the Life of Breath project indicates, our lungs have secrets, too.

References

  1. The phrase media vita in morte sumus is sometimes attributed to Notker I, also known as Notker the Stammerer, a Benedictine monk and poet. He is supposed to have coined it after observing a half-built bridge stretching shakily out over a chasm.
  2. Steven Connor, ‘Smog’, a talk broadcast on Nightwaves (Radio 3), 2nd December 2002, to mark fifty years since London’s Great Smog.
  3. See Steven Connor’s essay ‘Whisper Music’ for his (and Aristotle’s) comments on coughing.
  4. Steven Connor, ‘Unholy Smoke’, a talk given at Trailing Smoke, Art Workers Guild, London, 12 November 2008, accompanying the exhibition Smoke.
  5. See Mark Jackson, Allergy: The history of a modern malady (London: Reaktion).
  6. Mark Jackson (2004), ‘Cleansing the air and promoting health: the politics of pollution in post-war Britain’, in Medicine, the Market and Mass Media: Producing Health in the Twentieth Century, eds. Virginia Berridge and Kelly Loughlin (London: Routledge).
  7. Jackson, ‘The politics of pollution’.

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This blog is written by Jess Farr-Cox in the School of Arts at the University of Bristol, Research Secretary on the Life of Breath project.

A full description of the scope of research, including all the different research strands, can be found on the About the project page of the project website.

Do people respond to air pollution forecasts?

In 2010, the House of Commons Environmental Audit Committee published a report on air quality in which they concluded that “poor air quality probably causes more mortality and morbidity than passive smoking, road traffic accidents or obesity”. Concerned that the Government was still not giving air quality a high enough priority, the Committee published another report in 2011. To date, the Committee’s main recommendations have not been implemented. Amidst new evidence on the negative effects of air pollution on health and a court case that found the UK Government guilty of failing to meet EU air quality targets, the Committee published a third report on air quality last week.

One of the Committee’s recommendations is that the Government works more closely with the Met Office, the BBC and other broadcasters to ensure that forecasts of high air pollution episodes are disseminated widely together with advice on what action should be taken. The Committee’s rationale is that information about air pollution allows individuals to take action that reduces exposure. However, avoidance behaviour, such as staying indoors, imposes a cost on individuals that might exceed the perceived gains.

A BBC weather forecast for Bristol showing the commonly
encountered “green” air pollution forecast.

In a paper published this month in the Journal of Health Economics (Link with free access until 22 January 2015) I investigate responses to air pollution warnings in England. I obtained data on the air pollution forecasts issued by Defra from 2002 to 2008. During this period the daily air pollution forecast was freely available via the internet, a Freephone telephone service, Teletext and with the weather forecast on the BBC website. The forecast was disseminated using traffic light colour-coding, with green indicating low levels of air pollution, amber moderate and red high levels. “Red” forecasts were extremely rare (3% of forecasts) and “green” forecasts very common (70% of forecasts), so a change from “green” to “amber” (27% of forecasts) was akin to an air pollution warning. Hence, I define an “amber” or “red” forecast as an air pollution warning.

Air pollution warnings and hospital emergency admissions

First, I looked at indirect evidence of avoidance behaviour by estimating the relationship between air pollution warnings and hospital emergency admissions for respiratory diseases in children aged 5 to 19 years. I controlled for actual air pollution levels and therefore essentially compared days with a certain level of air pollution for which an air pollution warning was issued with days with the same level of air pollution for which no air pollution warning was issued. If parents and children do respond to air pollution warnings by reducing their exposure or taking other preventive measures, we expect fewer emergency hospital admissions on days for which an air pollution warning was issued compared to days with the same level of air pollution but no warning.

Looking at all respiratory admissions I found no effect. Looking at a subset of respiratory admissions – admissions for acute respiratory infections such as pneumonia and bronchitis – I also found no effect. Only when I examined another subset of respiratory admissions, namely admissions for asthma, did I find that air pollution warnings reduce hospital emergency admissions, by about 8%.

Presumably, it is less costly for asthmatics to respond to an air pollution warning. Standard advice for asthmatics is to adjust the dose of their reliever medicine and to make sure they carry their inhaler with them. Other types of respiratory disease require far more disruptive preventive measures such as staying indoors, making the cost of responding to air pollution warnings larger than the perceived gains.

Direct evidence of avoidance behaviour: visitors to Bristol Zoo

To find direct evidence of avoidance behaviour, I examined daily visitor counts to Bristol Zoo Gardens. Zoos are attractive destinations for families with children. Even with some animal houses under cover, most people will consider a zoo visit to be an outdoor activity and therefore susceptible individuals might adjust their plans to the air pollution forecast.  I found that lower temperature, more rain and higher wind speed reduced visitor numbers but found no effect of air pollution warnings on visitor numbers. Only when I looked at members – visitors who have an annual membership that entitles them to unlimited visits for a year – did I find that air pollution warnings reduce visits by about 6%. For members it is less costly to respond to air pollution warnings as they tend to be local residents who can just drop in for a quick visit. Thus, the perceived gains from postponing a visit are more likely to exceed the cost of postponing than for day visitors.

This graph shows monthly means of visitors to Bristol Zoo Gardens, daily maximum temperature and monthly total of air pollution warnings. Day visitors (grey bars) are far more responsive to temperature (yellow line) than to air pollution warnings (purple bars). Members’ visits (green bars) seem to be fewer in months with more air pollution warnings (purple bars).

Overall, my results show that whether individuals respond to air quality information depends on the costs and benefits of doing so: where costs are low and the benefits clear, responses are higher. This finding suggests, that wider dissemination of high air pollution forecasts as recommended by the Commons Environmental Audit Committee may not bring about the desired prevention of adverse health effects from air pollution. The Committee’s other recommendations aimed at lowering air pollution levels are more likely to succeed in preventing ill health.

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This blog is written by Cabot Institute member Katharina Janke, Research Associate in Applied Microeconomics and Health Economics at the Centre for Market and Public Organisation at the University of Bristol.
Katharina Janke