A report released last week by international experts shows pollution to have caused more deaths in the UK than in many other countries in western Europe. Air pollution is largely invisible, so it is hard to grasp how much damage it is doing to our health. But studies like the Lancet commission on pollution make it clear that poor air quality increases not only the likelihood of developing a range of respiratory illnesses, but also the frequency and severity of bouts of those illnesses.
Like many GPs, I see this “double hit” in the children and adolescents who come to surgery every day. Preschool children who live near main roads have an increased risk of developing wheeze triggered by viral colds – a condition we call “preschool wheeze”. Exposure to traffic pollution also increases the chance of a child developing asthma. For preschool wheezers and children with asthma, high pollution days can then trigger episodes of severe wheezing, especially when pollution has not been dispersed by the wind.
Worse still, as children grow, air pollution restricts the growth of their lungs. While it’s impossible to see these effects in a child sitting in front of you in the surgery, they have been confirmed in a number of research studies in the US and Europe. In effect we are creating a generation of adolescents with stunted lung growth.
As they become older adults, where lung function and capacity naturally decline, this reduced capacity is a big concern. Recent research shows that children with persistent asthma who enter adulthood with reduced lung growth are especially likely to experience faster decline in lung capacity, to a point where in early middle age (as soon as their fourth decade) they have developed chronic obstructive pulmonary disease (COPD).
I treated a middle-aged woman in my surgery last week in exactly this situation: she has persisting asthma that is not responding to treatment. Almost certainly the lung tests I asked her to do in a few weeks’ time will show irreversible lung damage. Such individuals are at major risk of long-term ill health, with frequent chest infections leading to further deterioration in lung function and probably early death.
Yesterday I watched a man struggling for each breath as though it would be his last, his lungs destroyed by COPD. His family watched helplessly. His chest infection hadn’t responded to antibiotics and strong steroid tablets; hospital admission by ambulance was his only chance.
This is why I welcome the London mayor’s new toxicity charge, which comes into force today and aims to drive down air pollution caused by diesel cars in the capital. Researchers in California recently showed that where pollution levels are driven down, children’s lung growth can at least partially recover.
The illnesses linked to air-pollution exposure in adults span other respiratory and non-respiratory conditions, including pneumonia, angina, heart attacks, strokes and even cognitive decline. Sooty particles and nitrogen dioxide inhaled by pregnant women increase the risk of pre-term birth, and low birth weight at term. Overall, therefore, air pollution adversely affects our health across our entire lifespan. These illnesses can have far-reaching effects on a person’s quality of life, that of their families, their livelihoods, and their finances. One patient I remember well lost her job due to recurrent severe asthma attacks.
Last week’s Lancet report named air pollution from vehicles and factories as the biggest killer, accounting for 6.5m deaths worldwide. We know that in Greater London, road transport generates 45% of toxic nitrogen oxide emissions. Modelling has shown that, alongside other measures, the percentage of diesel cars will need to be reduced from 57% to 5% of the total if London is to become compliant with legal limits.
The new toxicity charge has faced criticism from some car owners. I’m sympathetic to the concerns of people already squeezed by the high cost of living, but there are good reasons for introducing pollution charging. Illegally high levels of air pollution affect all people living and working in the capital, from pedestrians and cyclists to drivers themselves. The aim of this charge is to effect behavioural change. It aims to encourage owners of the most polluting vehicles to make fewer journeys, greater use of other transport options or eventually to change to a less polluting type of vehicle, such as an electric-powered one.
Air pollution in the UK, and especially London, has been described by many experts as a public health emergency
This kind of policy decision only happens when the evidence of harm to public health is overwhelming – as, for example, with banning smoking in public places. We know this approach works: the smoking ban has delivered major improvements in public health, reducing rates of pre-term birth by about 4%, childhood hospital admissions for asthma by 10% and pneumonia by almost 20%.
Air pollution in the UK, and especially London, has been described by many experts as a public health emergency. It’s a problem that cannot be solved without some effort on the part of individuals, policymakers and indeed the car industry. Driver charging alone won’t fix this problem, but it is necessary to help everyone breathe clean air. Nobody should have to suffer the ill effects of traffic pollution: they are entirely preventable.
• Professor Chris Griffiths is lead at the Centre for Primary Care and Public Health, St Bartholomew’s (Barts), and the London School of Medicine and Dentistry, and co-director of Asthma UK Centre for Applied Research. He has worked as a GP in east London for over 20 years