The New Zealand Waste Strategy, published in March 2002, is a long term strategy to help reduce waste, recover resources and better manage residual waste in New Zealand. It covers solid, liquid, gaseous and hazardous waste. The context of this study is policy development designed to deliver the strategy. Specifically, in order to ensure that efforts are directed to wastes where the most benefits can be obtained, and are directed in a manner that best achieves those benefits, it is important that the current state of knowledge regarding the environmental and health impacts of wastes is considered and collated.
Waste electrical and electronic equipment (WEEE) is a diverse waste category, and international opinions regarding the impacts of various substances contained within WEEE vary. This study considers the quality and weight of scientific evidence and reports on the state of knowledge regarding both consensus and diversity in scientific opinion pertaining to these impacts, both internationally, and as applicable to New Zealand.
The aim of the review is to assess the state of knowledge and consensus on the environmental and health impacts of post-consumer WEEE, within the context of New Zealand landfills and potential illegal dumping. The objectives and methods are contained in Appendix 1.
The objectives which need to be met in order to achieve the aim are:
- Conduct a literature review of policy developments relative to WEEE internationally, focusing on known relevant case studies, and the underpinning reasons for the developments.
- Use review material to characterise WEEE in New Zealand, within a global context, including the volumes and sensitivities of component types within the definition.
- Conduct a literature review of the state of knowledge regarding the relevant dose-response relationships between WEEE substances, and human health and the environment.
- Collate and analyse evidence in order to draw relevant conclusions regarding the state of knowledge and consensus on the environmental and health impacts of post-consumer WEEE, within the context of New Zealand landfills and potential illegal dumping.
The scope of each research component is presented in section 1.3.
Literature review is a well-recognised and valid research method. In order to review the state of knowledge, due cognisance should be given to the quality of sources. There is a recognised hierarchy of such sources, with peer-reviewed international journals and other scholarly publications being placed at the top of this hierarchy. Government policy processes often refer significantly to such sources, and so publications linked to such processes can also form a valid secondary source of evidence, provided the peer-reviewed sources referred to are valid. Likewise, other secondary sources and reviews of peer-reviewed literature can form useful indirect evidence which, cross-checked with original peer-reviewed sources, assist in providing a picture of the weight of scientific evidence and consensus. Where there is a paucity of peer-review material, non-peer reviewed information can be cited, but only with full notation in the report, and with the weight of evidence as analysed being adjusted accordingly. This approach summarises the method used in this study.
The scope of the review is limited to human and environmental impacts arising when post-consumer WEEE is disposed in landfills or illegally dumped. It does not include the environmental and health impacts from the manufacture/production and consumer use of the components and products, or during WEEE recycling. The scope of each main component of the review is as follows:
- International Policy and Regulation- Policy developments are summarised internationally, although the authors have selected case study regions and countries based on prior knowledge, in order to focus the effort within the time available.
- WEEE products - The study focuses on television sets (plasma, CRT and LCD), desktop PC's (incl peripherals), computer monitors (CRT, flatscreen), lap tops/notebooks, cell phones, fluorescent lightbulbs and shredder floc from WEEE including large domestic appliances.
- WEEE componentry - The study focuses on post-consumer printed circuit boards (including componentry and soldering), cathode ray tubes (including the glass), corrosion resistant metal parts, cabling and wires, plastic casing and batteries (including rechargeable).
- Dose-response - The study is restricted to review of the environmental and health impact of the following substances within WEEE: lead, mercury, cadmium, barium, hexavalent chromium, beryllium, brominated flame retardants, PVC (polyvinyl chloride), PBDE's (polybrominated diphenylethers), phosphorus.
The review is documented in the following order.
- Section 2 - Past, present and future developments in WEEE related policy and regulation is reviewed across the chosen international case studies.
- Section 3 - The WEEE products and componentry which are the focus of the review , within the New Zealand context.
- Section 4 - the state of knowledge regarding the dose-response relationships of the substances included in the review is documented.
- Section 5 - a brief analysis of the implications of changing practices and technologies in terms of health and environmental impacts and benefits. Conclusions of the review.