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Organochlorines Bulletin 4

June 1997, Ref. INFO 5

Bulletin 4 provides an update on the progress of the Organochlorines Programme. Items are presented on:

NZ Inventory Of Dioxin Emissions

A New Zealand inventory of dioxin emissions is underway that will collect data on dioxin emissions to air and water. The method for the work is similar to that used by the UK Department of the Environment, and the Netherlands. Woodward-Clyde Ltd are undertaking the work for the Ministry for the Environment. The final report is expected in early 1998.

Purpose

The study will provide valuable information for the development of national environmental standards under the Resource Management (RM) Act. The standards are intended to regulate dioxin emissions to air and water, and to establish soil clean up criteria for specific land uses.

Study Programme

The study will assemble NZ data on dioxin emissions to air and discharges to water. A judgement will be made about hazards which cannot be readily measured, such as the significance of potentially contaminated land. This will help identify the level of dioxin emission control needed, and assist in the development of a management strategy to minimise the hazard posed by dioxins in the NZ environment.

The work will proceed in 3 phases comprising: an initial study applying international experiences; the testing of specific emissions; and a review.

  1. The initial desktop study assumes that dioxins are being emitted to the NZ environment from the same range of industrial activities already identified in overseas studies. These include, for example, incineration processes, metallurgical industries, and the pulp and paper industry. By applying an "emission factor" appropriate to the industry or activity concerned, annual emissions to air and/or water can be calculated from operational data. The study will also consider the hazard that may be posed by dioxins in landfills, sediments and on some contaminated sites.
  2. The emission-testing phase will involve actual measurement of emissions from the key sources identified in the initial desktop study. These results will enable a more precise estimate of emissions to be made.
  3. The review phase will bring together the findings from the desktop and emission-testing phases. A nation-wide estimate of dioxin emissions will then be made.

The final inventory report will:

  • detail the estimate of dioxin emissions;
  • review the NZ situation in an international context;
  • describe the risk identification and ranking methodology used;
  • include an appraisal of uncertainties and data gaps;
  • propose priorities for future management.

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Human Body Burden of Organochlorines to be Estimated

An organochlorines contaminant survey is part of the National Nutrition Survey (NNS) of the Ministry of Health. The NNS survey is being conducted by the Life in New Zealand Group based at the University of Otago. A broad range of specialists involved with human health and nutrition have assisted in the design of the survey.

The survey is collecting information about diet, people's health, and body measurements. This large-scale survey is seeking the involvement of approximately 5,000 people across New Zealand. Those agreeing to participate in the survey (aged 15 years and over) will be asked to contribute a small amount of blood, some of which is to be analysed for a number of organochlorine compounds.

The purpose of the study is to determine the baseline level of persistent organochlorine contaminants (dioxins, PCBs and pesticides) in the blood of the general population. The survey will provide high quality data to assist the development of national environmental standards and guidelines for these organochlorine substances.

A number of smaller studies on organochlorines have been previously carried out in New Zealand. These have indicated that the body burden for the general population is in the low to medium range when compared similar studies in Europe and North America.

This study will obtain for the first time a detailed data-set on body burdens for a representative segment of the New Zealand population. This will allow the significance of the data to be assessed in the light of overseas research on human exposure and human health effects of dioxins and other organochlorines.

The Centres for Disease Control and Prevention laboratory in Atlanta, Georgia, USA, and ESR Ltd, Gracefield will be carrying out the analytical component of the study. Both laboratories are accredited by the World Health Organisation for the analysis of dioxins and PCBs in human tissue.

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Dietary Survey for Dioxins and PCBs

A selected range of food products are being tested by the Ministry for the Environment for the presence of dioxins and PCBs. The study is one of the investigations being carried out under the Organochlorines Programme. The purpose of the study is to estimate the level of dietary uptake of dioxins and PCBs by the New Zealand population. Apart from the determination of dioxin levels in milk, a study of this nature has not been previously carried out in New Zealand.

The consumption of food containing fatty components, such as meat, dairy products and fish, is the main way the general population is exposed to dioxins and PCBs. This fact is now well established by studies from Canada, USA, United Kingdom, the Netherlands and Germany. The New Zealand study is based on the protocols established by these studies so that the results can be compared internationally.

The New Zealand dietary survey is being conducted as follows:

  • A detailed study design, including the list of foods to be tested, has been developed by the Ministry for the Environment after consulting New Zealand and international experts. The food list was based on the most commonly purchased and consumed foods, including some overseas produce.
  • Food items were purchased from supermarkets in Auckland, Wellington, Christchurch, Dunedin and Napier, in accordance with the study protocol. Foods sampled include: bread, cereals, butter, cheese, ice-cream, milk, yoghurt, margarine, fats and oils, a range of selected meats (beef, lamb, pork, chicken), eggs, fish and shellfish, vegetables and snack foods.
  • Food samples were delivered to the analytical laboratory for preparation. The foods that are normally eaten as cooked food, were cooked prior to analysis.
  • From the concentrations of dioxins and PCBs found in the food samples, the average dietary intake of New Zealanders will be estimated.
  • The report of the study will include a comparison with the findings of similar studies in other countries.

The study is scheduled for completion later in 1997.

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Update on Environmental Surveys

Bulletin 3 gave an account of the survey of the levels of organochlorines in the New Zealand environment. The survey involved the collection of air, soil, water, sediment and biota samples from around New Zealand. The laboratory analysis of these environmental samples has been completed and the scientific reports of this work are now being prepared. These will be presented as a series of information reports to be published later in 1997.

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Keeping an Eye on POPs

In February 1997, the Governing Council of the United Nations Environment Programme (UNEP) agreed to commence negotiations in early 1998 on a global, legally binding instrument on a list of 12 persistent organic pollutants (POPs).

The POP chemicals are: organochlorine pesticides (aldrin, dieldrin, chlordane, DDT, endrin, heptachlor, hexachlorobenzene, mirex, and toxaphene); organochlorine chemicals used in industry (PCBs); and industrial by-products (chlorinated dioxins and furans). The UNEP decision calls for measures to reduce or eliminate emissions to air, and discharges to water and land, of the 12 POPs and, where appropriate, to eliminate the production and use of those which are intentionally produced.

UNEP recommends that realistic action should be taken to destroy obsolete stocks of these chemicals and to remediate environmental reservoirs. The international actions to be developed by UNEP are a precautionary approach to protect human health and the environment.

The UNEP decision calls for an intergovernmental negotiating committee to establish at its first meeting an expert group to develop science-based criteria for identifying any additional POPs for future international regulation.

In a related initiative, the UN Economic Commission for Europe (UNECE) is extending the Convention on Long-Range Transboundary Air Pollution (LRTAP). This is a regional convention (covering Europe and North America) initially designed to deal with sulphur emissions in continental Europe and the resulting acidification of the Scandinavian Lakes.

Work on a POPs protocol to the LRTAP convention is well underway. It will cover all twelve POPs identified for action under the global instrument as well as at least three additional substances (chlordecone, hexabromobiphenyl and polyaromatic hydrocarbons (PAHs)). Lindane is also under consideration.

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Dioxin is Evaluated as a Human Carcinogen

In February 1997 the International Agency for Research on Cancer (IARC) concluded that 2,3,7-8 tetrachlorodibenzo-p-dioxin (TCDD), considered the most biologically potent of the dioxins, is a human carcinogen.

A Working Group of 25 scientists came to this conclusion after reviewing all the published scientific data on the occurrence of cancer in human populations that are known to have been exposed to high levels of dioxins as a result of industrial accidents or environmental exposures.

The Group found that exposure to TCDD slightly increases the overall risk of all cancers among the most highly exposed workers by a factor of approximately 1.4. In comparison, heavy cigarette smoking increases the risk of lung cancer by a factor of approximately 20.

Taken into account in the Group’s judgement was the fact that TCDD causes cancer in a number of organs in experimental animals. It is assumed that the same cancer mechanism is likely also to operate in humans.

It was considered not yet possible to classify the carcinogenic status in humans of any other dioxin due to inadequate scientific evidence.

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Public Consultation on the Organochlorines Programme

The Ministry is preparing an explanatory pamphlet about the Organochlorines Programme. The pamphlet provides background information about the organochlorines being studied and outlines the issues being addressed under under the Programme.

Readers will be able to use a reply slip to request further information about the Programme and to indicate if they would like an opportunity to discuss issues of concern. The pamphlet will be ready for distribution later in July.

Consultation with Iwi

The Ministry has met with a Māori Focus Group in order to begin planning what procedures are to be followed when consulting with iwi on issues associated with the Organochlorines Programme.

Consultative Group member, John Hohapata (Te Runanga O Ngati Awa) and Murray Hemi (Maruwhenua, Ministry for the Environment) are leading this work which will be reported on in a future bulletin.

Do you want to be kept informed?

The purpose of the Bulletin is to provide the interested public with updated information about the Organochlorines Programme.

If you would you like to be placed on the mailing list to receive future issues of the Bulletin, or if your address label needs updating, please contact:

Organochlorines Programme
Ministry for the Environment
PO Box 10362
Wellington
Phone (04) 498 7400
Fax (04) 471 0195

Organochlorines Consultative Group

  • Howard Ellis, Ministry for the Environment (Chair)
  • Simon Buckland, Ministry for the Environment
  • Paul Dell, Local Authorities
  • Jim Waters, Ministry of Health
  • Dr Bill Jolly, MAF Regulatory Authority

NGOs

  • Dr Jim Barnett, Agricultural sector
  • Mark de Bazin, Timber industry
  • John Hohapata, Adviser on iwi
  • Jocelyn Keith, nominee of Ministry of Women's Affairs
  • Tony Petley, AGCARM, NZCIC, Waste Disposal industry
  • Peter Sligh, Pulp and paper industry
  • Michael Szabo, ECO
  • Norm Thom, CAE, IPENZ, NZIC, WMINZ
  • Simon Towle, ECO

Technical Specialists

  • Dr Michael Bates, ESR Communicable Diseases Centre
  • Dr Donald Hannah, ESR Wellington Science Centre

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