The health impacts of air pollution: event summary

This event was the first official APPG event of 2017 and aimed to explain the challenges that air pollution represents before later events in the year begin to develop ideas about how to tackle the problem.

Matthew Pennycook MP, the group’s chair, began the meeting by welcoming the audience and introducing the speakers.

Professor Anthony Frew, a respiratory consultant doctor working in Sussex opened remarks from the speakers. He said that there were a number of confusing claims about the impact of air pollution and would use his time to try to clarify some of the statistics. Importantly, he said that although he would be challenging the numbers, it was clear that air pollution is harmful – only the extent of the harm is what he was keen to question.

Professor Frew noted that the 1993 American ‘six cities study’ was the first to show incrementally higher death rates in cities associated with air pollution. In the UK, COMEAP (the Committee on the Medical Effects of Air Pollution) is the body that provides advice to government bodies on the impacts of air pollution. COMEAP’s estimate that 340,000 ‘life years’ are lost in the UK every year are based on decent evidence, but the way that information is presented to the public is problematic, Professor Frew said. The 340,000 life years figure is difficult for the public to understand, so COMEAP reinterpreted it and presented the research as linking air pollution to 40,000 deaths per year.

However, Professor Frew went on to say that the 40,000 deaths per year figure was misleading because it gave no indication of the age of the people dying, their existing health conditions and said that no one would ever have ‘air pollution’ on their death certificate. For these reasons, the focus should be on the impact of air pollution on morbidity instead of mortality.

Furthermore, Professor Frew spoke briefly about nitrogen oxides which are often claimed to be as damaging as particulate matter. He said that, so far, evidence on the health impacts of NOx is inconclusive but that about 10,000 of the 40,000 COMEAP deaths are identified as a result of NOx exposure.

It is important to remember that air pollution is not nearly as damaging as smoking and that the quality of the air in, for example, the city centres of the 1970s was significantly worse. Professor Frew closed by saying that exaggerated claims about the impacts of air pollution are damaging.


Dr Penny Woods, the Chief Executive of the British Lung Foundation then began her part of the session by promising to provide a more human perspective on these issues. She agreed that we do not yet know how NOx effects our health and conceded that the evidence on air pollution is always improving but, despite the uncertainty, we are sure that air pollution is bad for us.

Dr Woods said that the WHO labelled diesel as carcinogenic in 2013 and that COPD and asthma attacks can be brought on and conditions worsened by air pollution. She said that this resulted in around a 25% difference in lung capacity, as shown in one Californian study. Indeed, the impacts of air pollution tend to hit the most vulnerable hardest, with those on lower incomes more likely to live in high pollution hotspots and to have an existing respiratory condition.

Moreover, she made clear that airborne pollution harms children more because their stature puts them in close proximity to street exhausts, typically breath more rapidly and their lungs are more sensitive. Importantly, respiratory diseases are only one part of the problem – cardiovascular conditions such as stroke and dementia can also be impacts by poor air quality. This evidence, when taken together, should make us consider air pollution the modern era’s asbestos/smoking equivalent.

Agreeing with Professor Frew, Dr Woods said that morbidity associated with air pollution should be more regularly examined. She said that air pollution can impact the life chances of children and that high pollution episodes can lead to COPD and asthma sufferers feeling afraid to go outside. These challenges present in the context of the highest ever recorded A&E attendance for respiratory issues in years.

Dr Woods closed by suggesting that the government consider a range of policies to mitigate the risks of air pollution. She suggested a three-part programme to set up a national framework to clean up our air. The first was an ambitious implementation of Clean Air Zones in cities across the UK, following by new legislation to deal with the problem in the form of a new Clean Air Act, all underpinned by a recognition that the protection of those vulnerable to air pollution must be prioritised.


The last of the speakers, Mike Holland, an independent consultant focusing on the economic assessment of environmental ills, opened by giving the history of the UK’s approach to air pollution, commenting that the original concern was acid rain. Following further research on health impacts of air pollution, the focus shifted from acid rain in the 1980s. By the time of the 1993 six cities study, as mentioned by Professor Frew, it was clear that health impacts build up over time in conditions exposed to air pollution.

The latest figures show that air pollution can increase infant mortality several percent and costs the UK economy £20bn, a figure which takes into account lost utility, productivity, NHS costs and early deaths. Mr Holland also stood by the 40,000 deaths figure from COMEAP, which is a lower figure that Defra originally estimated. Importantly, the COMEAP figure ignores VOCs (Volatile Organic Compounds) and ozone so the figure could be higher still. The UK’s estimations are low compared to European and OECD studies and we are behind in analysing morbidity and lost productivity as a result of air pollution related illnesses.

In conclusion, Mr Holland said that a closer understanding of the interaction between climate policy and attempts to mitigate air pollution would be beneficial.


An extended Q&A session then began with MPs asking several questions of the panel. These focused on:

  • What councils could do to alleviate local air pollution;
  • How parliamentarians could help to bring the issue to the attention of the public without unduly frightening parents and sufferers of respiratory conditions;
  • The discrepancy in price between NOx and PM monitors and the use of these devices.

The panel responded that we need much more investment in active transport, that planning systems need to discourage rapid acceleration and braking (meaning consistent 20mph zones are preferable to speed bumps). The panel was conflicted about how to inform the public with some speakers standing by the 40,000 and others advising MPs not to deploy it.

The Q&A session kicks off

Key messages from the panel during the stakeholder Q&A included:

  • Poorer people tend to be more vulnerable to the impacts of air pollution because historically, cheaper housing was downwind from factories, they have less access to green spaces, they tend to drive older vehicles and to smoke;
  • The evidence for air pollution actually causing asthma is weak but there is strong evidence that it does exasperate the condition once it is contracted;
  • There was some speculation about how effective central and local policy has been to tackle air pollution as many areas remain over the limit values.

The event closed with Matthew Pennycook looking forward to the group’s activities in the year ahead. He said that the group was planning a workshop on the expected Clean Air Zone consultation in April/May and that a meeting focused on technology options to alleviate air pollution could be expected later in the year. He also alluded to plans that the APPG is forming to contribute towards National Clean Air Day in June.

Mr Pennycook thanked those present for coming and closed the meeting.