DoE outlines plans for improving air quality

A new framework for improving air quality has been outlined in a discussion paper issued by the Department of the Environment (DoE) on 31 March.1 The main innovations proposed are a three-tier system of air quality standards and local air quality management strategies - but local authorities will be expected to do the work with limited enhancement of their statutory powers and duties.

The discussion paper belatedly fulfills a commitment made in the 1992 progress report on the 1990 White Paper on the environment. It complements an earlier paper on the future of air quality monitoring (ENDS Report 226, p 36 ), and follows a recent report recommending air quality standards (AQSs) for benzene (ENDS Report 229, pp 4-5 ) - the first in a series which will deal with other pollutants.

The paper is candid about the need for "early and effective action" to improve air quality - and for a new framework to deliver this. The present approach is fragmented, when what is needed is something "to give a result that is more than the fortuitous sum of a large number of unrelated regulatory decisions and individual choices."

The paper is also forthright about current air quality problems. While the few existing statutory AQSs are now generally complied with, tighter air quality guidelines recommended by the EC and World Health Organization (WHO) are regularly exceeded - particularly for ozone, nitrogen dioxide, sulphur dioxide and carbon monoxide.

Recent studies have also highlighted new causes for concern about the health effects of some common pollutants, the DoE points out. Several have reported associations between fine particulates and respiratory illnesses and mortality (ENDS Report 230, pp 6-7 ), while work in the UK has shown associations between respiratory diseases and smoke and SO2 levels well below current EC guide values. And the sharp increase in asthma since the late 1970s (see pp 31-32 ) has been linked to rising emissions from vehicles.

The paper also notes that there are "substantial costs from low level air pollution in terms of health services, impediments to economic efficiency, the cleaning of buildings and the environment, and in the perception of the attractiveness of British cities internationally as places to live and do business."

However, the measures proposed by the DoE might be felt to lack a matching sense of urgency. In particular, the paper appears to have fallen foul of the current Ministerial aversion to new regulations. And the idea of short-term traffic restrictions even during health-threatening pollution episodes has been almost entirely discounted.

The paper needs to be read in a wider, EC context. The European Commission has been promising a new framework Directive on air quality management for some time, and the latest presentation of its thinking (ENDS Report 225, pp 39-40 ) suggested possible conflicts with the Government's ideas on key issues such as the nature and legal status of AQSs, and the assessment, maintenance and improvement of air quality.

The discussion paper can therefore be taken as the UK's opening shot for the forthcoming negotiations on the Directive. Indeed, it comments on the Directive explicitly, arguing that it "must avoid unnecessary regulation, have regard as far as possible for cost/benefit considerations and cost-effectiveness and be consistent with the principle of subsidiarity."

The DoE foresees action at two levels to create the new policy framework. At national level, the principal innovation will be a system of AQSs. At local level, the key development will be air quality management strategies.

On AQSs, the DoE's Expert Panel on Air Quality Standards is expected to follow up its recent paper on benzene with reports this year on ozone, 1,3-butadiene, sulphur dioxide and carbon monoxide. Proposals on particulates and nitrogen dioxide will follow.

One of the key questions is what legal status AQSs should have. Three of the four EC Directives on air quality - dealing with smoke and SO2, lead and nitrogen dioxide - set legally binding AQSs to be achieved within a specified deadline, and in the former two cases forced the Government to introduce the necessary improvement programmes. On the other hand, the non-binding guidelines recommended by the EC and WHO have made no noticeable impact on policy.

The discussion paper accepts that guidelines alone provide "little impetus for action", but argues that legally binding AQSs accompanied by strict deadlines "can impose an unnecessarily tight straitjacket when the factors influencing air quality may be wide ranging and the capacity to ensure a particular outcome limited." This is particularly likely to be the case with pollutants from vehicles and secondary pollutants such as ozone.

The course which the DoE appears to favour is therefore to use AQSs as "a basis for targets for the work of regulatory bodies, backed if appropriate by an obligation on them to use their powers to promote remedial action if a target is not met." Whether this approach would be consistent with the forthcoming EC proposal is unclear, since the Commission's thinking on this issue appears to be in a state of flux.

However, a conflict does seem possible between the UK and the Commission on another issue. The DoE's paper suggests that AQSs should be based primarily on health effects, while the Commission has made it clear that AQSs proposed once the framework Directive is agreed will aim to provide a high level of protection for both humans and the environment.

The paper goes on to propose a three-tier system of AQSs:

  • At the upper end would be an "alarm threshold" above which there is considered to be "serious risk of widespread adverse health effects on a significant proportion of the population."

    If an alarm threshold was "approached or exceeded", emergency measures such as "widespread warnings to the public, together with action to reduce emissions quickly" could be appropriate. However, the paper stresses that such action "should rarely, if ever, be needed" in the UK - suggesting a reluctance to take action even if there was a repetition of the severe pollution episodes in two recent winters, when nitrogen dioxide levels in several cities reached unprecedented highs (ENDS

    Reports 205, pp 7-8 , and 218, p 7 ).

  • The middle tier would be a "long-term acceptability threshold". This would define "an equilibrium point beyond which further action to reduce pollutant levels would not - given current circumstances and scientific knowledge - be sensible."

    The acceptability threshold would generally be the target to be pursued, over a period to be determined in the light of a cost/benefit assessment. However, the paper adds, in cases where "the balance of costs and benefits was unclear, or the technical feasibility or effectiveness of control strategies uncertain, it might be appropriate to set operational targets above the threshold, with an obligation to review them in the light of experience." Exactly who would be responsible for weighing costs and benefits in a system of this kind has not been made clear.

  • At the lower end of the spectrum would be a "background threshold" - essentially only a reference point defining the level of an air pollutant which might be expected without human activity.

    Although national policy measures - such as vehicle emission controls, economic instruments, and emission standards for stationary sources - would continue to contribute to the attainment of AQSs, the main innovation proposed by the paper is at local level.

    The DoE apparently envisages that this initiative can be pursued without additional legislation. Local authorities with "significant" air quality problems, it says, "should consider" designating an "Air Quality Management Area", and after consulting the Environment Agency and local interests prepare an "Air Quality Management Strategy" for the pollutants concerned. Where the problem was not solely of local origin, local authorities "should consider" preparing a joint strategy.

    Councils have been invited to come forward with proposals to test the new approach.

    Exactly how the DoE intends areas where AQSs are at risk of being breached to be identified is not clear. The paper says that monitoring, along with emission inventories and modelling, are "essential tools" for this purpose. But it rejects the idea of imposing a statutory duty on all local authorities to carry out monitoring. This may prove to be a serious weakness, since local authorities are generally told by the Government that the costs of anything which is not required of them by law must be met by a reallocation of their existing priorities and funds.

    The paper does, however, puts forward proposals for some additional powers and duties. Local planning and highway authorities might be obliged to "have regard" to the impact of planning and transportation proposals on air quality. And councils might be given powers to make spot checks on smoky vehicles, and to ban them from entering areas at risk or take other enforcement action.

    The National Society for Clean Air (NSCA) has broadly welcomed the paper. But it believes that the three-tier AQSs proposed are too coarse and would provide little guidance on priorities for most air quality management problems, which occur between alarm and long-term acceptability thresholds. The AQSs also do not match the finer bandings used to inform the public about air quality.

    The NSCA also wants the Government to take a more robust approach to transport planning. The DoE's paper suggests that traffic calming and management schemes, pedestrianisation and vehicle restrictions will have an increasing role to play in achieving air quality objectives. But the NSCA would like to see a duty imposed on local councils to demonstrate a response to this guidance in the packages of transport initiatives they submit for central funding.

    Responses to the paper are due in by 13 June, and the DoE has promised to publish its conclusions later in the year.

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