Memorandum submitted by Dr Mark Broomfield, Enviros Consulting Ltd (AQ 17)

1. This evidence is provided by Dr Mark Broomfield, technical director with Enviros Consulting Ltd. The views set out in this document are my own, and do not necessarily represent the views of Enviros Consulting Ltd.

2. In summary, my evidence is as follows

Air quality differs from other areas of environmental science, in that it can be readily measured. There are tools available to forecast air quality, and their strengths and limitations are well understood.

Air quality differs from other areas of environmental science, in that public exposure to polluted air is very hard to manage.

The Government's monitoring systems provide an adequate measure of air quality. A change in the substances measured, and a move away from measurement towards more detailed analysis would be helpful.

The health and environmental risks caused by poor air quality are relatively well understood. Research into some new areas (e.g. micro-organisms, fine particulate matter and ammonia) would be helpful.

Appropriate systems are in place for control of emissions and management of ambient air quality.

The delivery of improvements in air pollution derived from road traffic is the key weakness in the system. Consequently, air quality continues to fall below the relevant standards and objectives in some areas.

It is recommended that guidance is given to local authorities to support them in deciding to take steps to manage air quality, where the need to do so outweighs other considerations.

It is recommended that a Public Service Obligation to deliver satisfactory air quality could be placed on relevant departments.

3. The Committee has asked to be informed on a number of specific issues. I have set out my views and supporting evidence on some of these issues below.


4. It may be helpful for the Committee to appreciate key differences between the management of air quality, and the management of other environmental pathways for exposure to pollution.

5. Air quality science has had the benefit of many years of investment in research to develop tools for monitoring and forecasting/estimating air quality. Additionally, air quality issues are relatively amenable to the use of forecasting tools. For example, the influence of meteorology on the dispersion of air pollutants is essentially repeatable, and can therefore be coded into predictive model systems. In contrast, other pathways for exposure to environmental pollution cannot be forecast in the same way. This means that there are highly detailed tools available for measuring and forecasting air pollution. The use of these instruments and models is more widespread than is the case for other environmental media.

6. A very important difference is the difficulty of managing exposure to air pollution. In the case of (for example) water pollution, people can be advised or prevented from drinking a particular water supply. In the case of a hazardous contaminated land site, access can be prevented. While these measures are undesirable, relatively straightforward controls are available. In contrast, in the case of air pollution, the public cannot be advised not to breathe the air. The management measures broadly comprise moving people away from a source of pollution, and reducing emissions from the source(s) of air pollution. In many cases, neither option is particularly straightforward or attractive.

7. The availability of measurement and forecasting methods, and the difficulty of control, have shaped the practice of air quality management in the UK.

The monitoring and modelling systems used by the Government and whether these provide an adequate measure of air quality;

8. The Government's systems for measuring air quality comprise principally the following:

A wide-ranging network of air quality monitoring stations (

Interpolated datasets of background air quality (

A framework for local authorities to assess air quality in their boroughs known as "Local Air Quality Management," supported by a set of assessment and modelling tools (; see also

A system of regulation of industrial pollution implemented by the Environment Agency and local authorities.

9. The availability of detailed air monitoring methods, together with quality assurance procedures and systems for data dissemination means that the Government's monitoring systems provide an adequate measure of air quality.

10. The monitoring systems used on behalf of national and local government deliver an extremely large body of data. There is limited benefit in continuing to expand this network. Instead, attention should be limited to monitoring air quality in areas of high pollution; areas which are representative of the range of exposures experienced by the public; and locations which are required to fulfil obligations under European directives.

11. It would be more beneficial to investigate the measurements carried out in more detail. At present, most datasets are simply analysed to identify compliance with air quality objectives and guidelines. There is much more information within these datasets which could be developed - for example, to support models of exposure. The European-funded OpenAir project is an example of work in this area ( More detailed data analysis could be brought more into the mainstream of Government's thinking on air quality.

12. It would also be very useful for investment to be shifted towards measurements of other substances, rather than focusing mainly onEn those specified under the European directives. Substances which are particularly relevant at present include ultrafine particulate matter and nanoparticles. There is considerable concern about these fractions of particulate matter, but very little environmental data compared to the much more widespread data available for larger size fractions such as PM10. There is a need for baseline measurements of Chromium VI with an appropriate Limit of Detection, following the guideline published in the recent EPAQS report More widespread measurements of airborne hydrogen fluoride and hydrogen chloride would be helpful in support of the development of installations such as power stations and waste management facilities. Measurements of a wider range of volatile organic compounds, particularly focusing on halogenated compounds, would also be helpful for a wide range of industrial and waste management processes.

The extent to which the Government fully understands and has identified the health and environmental risks caused by poor air quality;

13. There has been considerable research into the health and environmental risks posed by poor air quality. This has highlighted potentially significant health risks posed by a range of air pollutants, and has led to the development of methods for evaluating these risks to health (e.g. Health risks are also considered by the Expert Panel on Air Quality Standards. While there remains some uncertainty in this area, compared to other environmental pathways, the health and environmental risks caused by poor air quality are relatively well understood. This enables the loss of life and associated costs to the UK economy resulting from poor air quality to be estimated-for example, as in the introduction to the Environmental Audit Committee (EAC) call for evidence.

14. The risks to health and the environment caused by poor air quality are discussed in the Air Quality Strategy 2007, and form a key input into the specification of air quality standards, and the system of air quality management in the UK.

15. The main outstanding areas of knowledge and understanding are on substances other than those forming the mainstream of local air quality management. Further attention to these substances would be beneficial:

Micro-organisms from sources including agriculture, waste management and sewage processing;

Ultrafine particulate matter and airborne nanoparticles; and

The potential effects of ammonia on ecosystems. There is very limited evidence of the effects of ammonia on ecosystems. This limited evidence has been used as the basis for a substantial regulatory burden on operators of intensive livestock farms and waste management facilities. Further evidence on the significance of such effects, and the types of habitat site which could be affected would be helpful.

Is the delivery chain for air quality coherent, integrated, coordinated and effective? Do the bodies with responsibility for managing air quality have appropriate incentives, understand their role and responsibilities, and have adequate resources?

16. In broad terms, the delivery chain for air quality management is as follows:

Assessment of air pollution from individual sources (i.e. "what goes up"): this is carried out by the source operators, and is typically regulated by the Environment Agency and/or local authorities. Appropriate systems are in general in place via the pollution control or land-use planning systems.

Assessment of ambient air quality (i.e. "what comes down"): this is the responsibility of local authorities. Now that local authorities have had considerable experience of local air quality management, they generally have appropriate arrangements in place for air quality assessment.

Management of ambient air quality where needed: this is the responsibility of local authorities working jointly with the Highways Agency, the Environment Agency, and local authority highways and environmental teams. The delivery of improvements in air pollution derived from road traffic is the key weakness in the system.

17. Road traffic is the principal cause of air quality problems in the UK, and lies behind the vast majority of declared air quality management areas. However, it is often difficult to deliver genuine improvements in air quality in these areas. The reasons for this include the following:

It can be technically difficult to identify an effective solution to an air quality problem.

Dealing with an air quality problem (e.g. by restricting traffic) could result in further problems (e.g. reduced economic activity in a town centre, or air quality problems elsewhere).

Changes in or restrictions to road traffic tend to be unpopular with local people, and are difficult to deliver politically. People are often not aware of an air quality problem, but would be acutely aware of traffic restrictions. Good practice for public consultation on air quality was studied by the University of the West of England (

The primary responsibility of highways bodies is the safe and effective delivery of road transportation infrastructure. This can work against the need to reduce traffic to deliver satisfactory air quality.

18. In some cases, air quality and highways improvements can go hand in hand. However, where a choice has to be made between improving air quality and maintaining highway capacity, it is often air quality which is sacrificed. The evidence for this is the relatively high number of air quality management areas in which air quality continues to fall below the relevant standards and objectives.

The steps that need to be taken to ensure that air quality targets will be met in the future.

19. To meet air quality targets in the future, it is important that an appropriate balance is struck between achieving air quality, and other issues which affect the public. These include economic issues, land-use policies, noise, health and wellbeing, and highways considerations (safety, capacity etc). The weight to be given to achieving air quality targets and the means by which this can be achieved will always be a matter of judgement.

20. It may be helpful for air quality policy guidance ( to assist local authorities in identifying unambiguously what steps are appropriate in order to achieve air quality targets, having regard to other potentially competing policy objectives. This could give more weight to a local authority in taking the difficult decisions and securing the changes needed to deliver genuine improvements in local air quality.

21. The benefits of achieving air quality targets can be quantified in economic terms, and set in the context of the costs and benefits of other policies. In the light of this, it may become apparent that achieving the targets is not a sufficiently high priority at present. One option to increase the priority given to achieving air quality targets would be to specify a Public Service Agreement for Defra, the Department of Health and the Department for Transport to work together to deliver satisfactory air quality under the LAQM regime.


14 December 2009