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1 Introduction

1.1 Purpose

This report contains new ambient air quality guideline values for New Zealand, and updated guidance on how they should be used to manage air quality under the Resource Management Act 1991 (RMA). The new guideline values replace those first published by the Ministry for the Environment in 1994. The 2002 Guidelines follow the previous guidelines in applying only to ambient air outside buildings or structures, and not to indoor air or air in the workplace.

The primary purpose of national ambient air quality guidelines is to promote sustainable management of the air resource in New Zealand.

Guideline values are the minimum requirements that outdoor air quality should meet in order to protect human health and the environment. Where air pollution levels breach guideline values, emission reduction strategies should be implemented to improve air quality. Where levels do not breach the values, efforts should be made to maintain air quality and, if possible, reduce emissions. This is particularly important for those pollutants, such as particles less than 10 microns in diameter (PM10), for which the guideline value cannot be based on a 'no observable adverse effects level'.

Guideline values should not be used as limits to pollute up to. If pollution approaches the guideline value, then air quality is comparatively poor and has been degraded from its background state.

Updated advice on how to apply the guideline values to assess air quality and prepare emission reduction strategies is provided in Chapter 3. Only limited advice is given on how to - and, in particular, how not to - apply the guideline values to assess discharges to air. Further guidance on assessing discharges to air from point, area and line sources will be provided in a separate report available for comment by the end of 2002.

As well as providing updated values for the contaminants covered in the 1994 Guidelines, the 2002 Guidelines include new priority contaminants:

  • benzene
  • 1,3 butadiene
  • formaldehyde
  • acetaldehyde
  • benzo(a)pyrene
  • mercury
  • chromium
  • arsenic.

They also provide guidance on assessing the potential impacts of air pollution on ecosystems.

The 2002 Guidelines were developed as part of the Ministry's Air Quality Management Programme. The Programme develops well-debated national guidance for councils, industries and communities involved in managing air quality, and investigates, develops and implements appropriate national policy tools to improve air quality.

The document is structured as follows.

  • Chapter 1 (this chapter) describes the process involved in developing the guidelines, briefly covers the legal framework under which air quality is managed in New Zealand, and explains the status of the guideline values and how they will be reviewed.
  • Chapter 2 contains the guideline values, along with descriptions of the health effects of each contaminant and reasons for the chosen guideline value.
  • Chapter 3 discusses the framework for air quality management and how guideline values can be used to determine the state of the air environment, devise regional criteria, set reduction targets and develop reduction strategies for both regional and national planning processes.
  • Chapter 4 introduces an approach to assessing and managing the impacts of air pollution on ecosystems using critical levels.

1.2 Background

The development process

The new and revised guideline values and guidance on how to use them are derived from:

  • comprehensive reviews of research on the health and environmental effects of the priority contaminants (see below)
  • a review of how the 1994 guideline values were applied to managing air quality in New Zealand (Ministry for the Environment, 2000c, Chapter 2)
  • consideration of current air pollution levels in New Zealand (Ministry for the Environment, 1998c; Chiodo and Rolfe, 2000)
  • discussions in expert working groups and 17 consultation meetings
  • submissions on the discussion document Proposals for Revised and New Air Quality Guidelines - Discussion Document (Ministry for the Environment, 2000c)
  • submissions on the Summary of Submissions Received on the Discussion Document and Proposals for Amendments (Ministry for the Environment, 2001c)
  • developments through the Ministry's Environmental Performance Indicators Programme.

The reviews of environmental and health research used to determine the new guideline values are written up in several technical reports prepared for the Ministry for the Environment:

  • Health Effects of Five Air Contaminants and Recommended Protective Ranges.Air Quality Technical Report 12. L Denison, K Rolfe, and B Graham, 2000.
  • Health Effects of Eleven Hazardous Air Contaminants and Recommended Evaluation Criteria. Air Quality Technical Report 13. J Chiodo and K Rolfe, 2000.
  • Preliminary Review of Strategies for Managing Air Quality. Air Quality Technical Report 14. T A'Hearn, W Robins and K Rolfe, 2000.
  • Effects of Air Contaminants on Ecosystems and Recommended Critical Levels and Critical Loads. Air Quality Technical Report 15. C Stevenson, V Hally, and M Noonan, 2000.

The Ministry has also prepared a pamphlet seeking input from Māori, and discussed the proposals at several hui throughout New Zealand. Potential issues of concern for Māori are discussed later.

What the Guidelines don't cover

The Guidelines do not cover:

  • the potential synergistic effects of different contaminants - if synergies are a potential issue they should be considered on a case-by-case basis, using up-to-date research on the cause-and-effect relationships
  • the effects of spray drift arising from agrichemical application - these are managed by regional air quality plans and the Hazardous Substances and New Organisms Act 1996 (HSNO), and will be subject to requirements imposed by the Environmental Risk Management Authority (ERMA)
  • organochlorines - the Ministry's Organochlorines Programme has recently released a draft Action Plan for Reducing Discharges of Dioxins to Air (Ministry for the Environment, 2001d) addressing the generation, transport and fate of these compounds in the general environment (see Appendix 1)
  • management of odour, dust nuisance and degraded visibility - these are addressed as separate projects within the Ministry's Air Quality Management Programme; reports and good-practice guides on these issues can be downloaded from the Ministry's web site at:

1.3 Legal and policy framework

The legal and policy framework for environmental management in New Zealand directs how air quality is managed in New Zealand. This information is generally well known, so this section only briefly covers the key points.

Regional air quality management

Under the RMA, regional councils and unitary authorities are responsible for managing discharges into the air and therefore for managing the quality of the outdoor air that we breathe. The purpose of the RMA is to promote the sustainable management of natural and physical resources, including air.

Sections 5 to 8 of the RMA outline the key principles and purpose of the RMA. Section 5 provides that the purpose of the Act is to promote the sustainable management of natural and physical resources including safeguarding the life supporting capacity of the air, while sections 6 to 8 describe other matters (including the Treaty of Waitangi) which must be considered when making decisions. Of particular relevance for air quality management is section 7(f), which states that persons exercising powers under the Act must have particular regard to the:

(f) Maintenance and enhancement of the quality of the environment.

Section 30 of the RMA specifies the functions of regional councils and unitary authorities, which include controlling the discharge of contaminants into the air. Councils are also responsible for gathering sufficient information about the state of the environment to enable them to carry out their functions (section 35). To manage the environment, councils can prepare regional policy statements or regional plans specifying objectives, policies and rules to address any issues of concern (sections 63 to 70).

The costs and benefits of measures to improve air quality through regional policy statements and regional plans must be analysed in accordance with section 32 of the RMA. The options must be discussed with, and take into account the views of, the local community before being implemented.

Further information on establishing air quality management plans under the RMA will be available in the Quality Planning web site at

National policy development

The Government's key goal for public sector policy and performance relating to the environment is to:

Protect and enhance the environment - treasure and nurture our environment with protection for ecosystems so that New Zealand maintains a clean, green environment and rebuilds our reputation as a world leader in environmental issues.

The Minister for the Environment is responsible for the Government's environment portfolio and for achieving this key goal. The Ministry for the Environment advises the Minister, on whose behalf it carries out Ministerial duties under various laws, such as the RMA. These duties include promoting and developing national tools to achieve sustainable air quality management (see Appendix 1).

The Ministers and Ministries of Health, Transport, and Economic Development are also involved in developing policies and legislation that influence discharges to air, particularly where national solutions are required. The Ministry works closely with these departments to develop and implement national strategies for improving air quality.

1.4 Māori and air quality

Air and air quality can be described as both a taonga and a part of the traditional kainga.

The Crown is responsible under article two of the Treaty of Waitangi to actively protect Māori Treaty rights. The Ministry is committed to honouring the Treaty of Waitangi and obligations to Māori outlined in the RMA. We aim to incorporate Māori values into the development of environmental guidelines so that they recognise both Western science and Māori views.

In 1999 the Ministry discussed environmental issues concerning Māori at a number of hui around the country. Discussions highlighted the need for the Ministry to integrate its programmes on guidelines and standards to reflect the holistic view of the environment traditionally held by Māori. To focus discussion on the proposed air quality guidelines, the Ministry prepared a pamphlet entitled Review of the Ambient Air Quality Guidelines: Seeking comment from Māori, and attended several further hui in 2001 to discuss the guidelines as well as other Ministry programmes.

General discussions at these hui emphasised the need to minimise discharges to air by applying the best practicable option, support for national environmental standards to protect the air, the importance of recognising Māori values in making decisions about air discharges (especially around areas such as marae and waahi tapu), and the involvement of Māori in local planning processes.

The Ministry's work on the pamphlet highlighted the following issues for Māori in terms of the potential effects of air pollution on their health.

  • Māori are more likely than non-Māori to be hospitalised for asthma. Although Māori asthma rates decreased in the early 1990s, rates have increased recently.
  • Cancer is one of the leading causes of death for Māori and non-Māori, but the incidence of cancer remains higher among Māori.
  • Māori experience far more cases of respiratory illness (such as asthma and emphysema) and heart disease than non-Māori.

Other issues of significance and interest to Māori include:

  • deposition of air pollutants onto mahinga kai, waahi tapu, waterways and marae
  • reduction of visibility
  • increases in airborne smell
  • the impact of contaminants on important or valued sites; for example, discharge material from the flue of a crematorium can be blown over puna wairoa or mahinga kai.

In developing the air quality guidelines and the Air Quality Management Programme, the Ministry has attempted to take these concerns into account, and to develop an approach that is consistent with section 6(1), 7(e) and 8 of the RMA. In particular we have considered:

  • that Māori represent one of the sensitive groups the health protection guideline values are aiming to protect
  • the wider impacts of air quality on plants, animals and other materials, including water and soil, in developing the guidance on assessing and managing the impacts of air pollutants on ecosystems
  • how to improve the ability and opportunity for Māori to effectively control, manage and regulate air quality within their rohe (boundaries) and according to their own cultural preferences.

1.5 Status of the Guidelines

Guideline values and advice on how to apply them are not legislative requirements under the RMA or any other legislation.

However, the process and consultation involved in preparing the Guidelines mean that they reflect well-debated, expert, national and international best practice and knowledge. They contain sound, consistent and good-quality advice. As such they should be afforded considerable weight in decision-making on air quality management. The new guidance on how to apply the Guidelines aims to eliminate inconsistencies and confusion about applying them in the past.

Regional councils and unitary authorities need to determine the extent to which they will apply the new guideline values and guidance. Monitoring programmes, rules in regional air quality plans, emissions inventories, existing resource consents, and applications for consents may need to be amended or revised. Councils will also need to assess the costs and benefits of measures required to achieve the revised Guidelines (as required by section 32 of the RMA), and to discuss these options with their local communities through the regional planning process.

Through submissions on plans and workshops the Ministry will encourage councils to incorporate the revised Guidelines and guidance into planning documents and monitoring programmes as soon as practicable.

1.6 Reviews

Developing and applying guideline values is an iterative process. New research findings regularly enhance our understanding of health effects of pollutants and ways in which emissions can be reduced.

Because of the rapid rate at which research on air quality develops, the Ministry intends to review and update the air quality guidelines and their application on at least a five-yearly basis. Some contaminants will be reviewed sooner, including carbon monoxide, particles (PM2.5) and hydrogen sulphide. Reviews for these contaminants will commence in 2002 and will be completed by 2004. Other guideline values may be reviewed sooner than the five-year cycle if new international or national research suggests that the values need changing.

The reviews will examine research on the health and environmental effects of the particular contaminant, the recommended monitoring method, and the effectiveness of the guideline value in achieving sustainable air quality management. Data compiled for the Environmental Performance Indicators (EPI) Programme will be used to determine the effectiveness of the Guidelines and other policies towards achieving sustainable air quality management.