The reviews of policy developments, WEEE components and substances, and the environmental and health effects of these substances upon landfilling or illegal dumping demonstrates a rapidly developing and mixed picture. In some areas, there is clear consensus and parallel directions in policy and action, while in others, there is less certainty and even some controversy.
In policy terms, the WEEE and RoHS Directives place the EU at the forefront of legislative developments. The US provides a range of local legislation, bans and initiatives across different states. This is not the intention of either the manufacturers and retailers, or the public or government, it simply reflects the progress different states have made so far in managing the real and potential hazards and risks of WEEE. While the systems vary, Europe and the US are indicative of the moves across the developed world to tackle the rapidly growing problem of WEEE. In the developing world, anecdotal evidence suggests the uptake of WEEE management systems is less advanced, although manufacturing companies in these countries are aware of the developments and the implications for them in supplying products into European markets.
As a result, market transformation is happening, especially driven by the WEEE and RoHS Directives, and it can be expected that countries which do not implement appropriate systems will be increasingly subject to imports which are non-compliant with these Directives; in other words, they will become a dumping ground for the more toxic EEE.
The detractors of the European approach cite implementation costs and uncertainties over some toxicity information (see below). Other potential problems occur when the costs of end-of-life are borne by consumers rather than manufacturers. Rising landfill costs, where they are passed on directly to consumers, can increase the incidence of illegal dumping. However, evidence is mixed; a Tidy Britain group report, "Effects of the Landfill Tax on Flytipping" (published in 1998), did not establish a clear link between the tax and increased fly tipping. Also in the UK, DEFRA (2006) has developed Flycapture to help get a better picture of the problem facing authorities and to track the future impact of fly-tipping. Flycapture is showing that around 50% of fly-tipping incidents involve household waste even though householders are not subject to landfill tax at civic amenity sites in the UK.
Through present WEEE management systems, valuable materials are disposed of and lost to future generations through the present methods of waste management of discarded electrical products. Along with the loss of resources, substantial pollution of the environment from mining is of concern. It is not possible to give exact figures on the environmental impact of the extraction of all the materials contained in electrical and electronic equipment. This depends very much on the site and region where the materials are extracted. However, the process leading to the extraction of these metals and their general impact on the environment are well known and documented. This itself adds to the case for reduction of WEEE at source, through application and development of eco-design in EEE.
As indicated in the literature (European Commission, 2000), the risks relating to placing discarded electrical equipment in landfill are due to the variety of substances they contain. Due to the range of different substances in WEEE, unpredictable toxic hazards are potentially created by landfilling. Co-disposal with municipal waste adds to the unpredictability, and spreads the problem. While licensed, controlled landfills with liners do not eliminate risks of pollution, the potential amounts and concentrations - and resulting environmental impacts - are considerably higher when WEEE is put in uncontrolled landfills.
In the EU, the 'Precautionary Principle' has been applied in requirements to remove 'substances of concern', pending clarification on their hazardousness and appropriate treatment. Furthermore, some other components that are not specified in Annex II may be hazardous, and may need to be removed to render the WEEE item non-hazardous, for example, substances containing phthalate plasticizers or lead stabilisers, lithium batteries, and components containing mineral wools that are classified as category 3 carcinogens (AEA, 2004).
Notwithstanding, there is good (although not perfect) information about the toxicity of many WEEE components and the likelihood of damage to human health and the environment. Lead has well-known toxicity and is used widely in soldering, CRT screens and other EEE components. While the literature is less conclusive about the rate of leaching of lead from landfills, and further monitoring is required, it is well-established that lead leaches from landfill and evidence indicates that even low concentrations of lead can cause serious developmental effects on the brains of children. Mercury is used in smaller amounts in EEE, however, leaching of elemental mercury and the vaporisation of metallic mercury and dimethylene mercury, both contained in WEEE, are of concern. While leaching of mercury in large concentrations from well-managed landfills is unlikely, mercury is highly persistent in the environment and so causes long-term effects.
Cadmium is also highly persistent in the environment, although in the quantities it occurs in WEEE, it is most likely to be of concern to humans in the case of assembly and recycling/reprocessing workers. Chromium VI (hexavalent chromium) is of increasing concern because of its toxicity and leaching potential, while beryllium is less likely to cause a problem to humans and the environment, apart from assembly workers associated with assembly and disassembly of EEE. When BFR PVC plastic or cadmium containing plastics are landfilled, both PBDEs and cadmium may leach into the soil and groundwater, along with other components of these compounds and mixtures. BFRs are a major problem facing risk assessment, as they offer health benefits in reducing the risk of EEE catching fire during use, yet they are also toxic to both humans and the environment. Different BFRs provide different toxicity but the whole substance group of BFRs is listed on the Danish list of unwanted substances. Of the main groups, PBBs, Penta-BDE and Octa-BDE are banned under the RoHS Directive from July 2006, and, while Deca-BDE has been exempted from this ban, it is currently the subject of legal challenges from both the European Parliament and Denmark. With the current literature incomplete, there is enough evidence to warrant consideration of a precautionary ban on these BFRs, pending the development of alternatives which are already appearing on the market.
PVC is mainly a concern due to the risk of the release of chlorine, heavy metals used as stabilisers and phthalate plasticizers. The PVC industry is committed to tackling lead stabilisers within a decade, but this leaves other issues unresolved. A precautionary approach would therefore be to assume that the potential for leaching of chlorine, heavy metals and phthalates is possible. Similarly with phosphors, additives such zinc, terbium and arsenic are the main areas of concern regarding toxicity and pollution risk, although less-publicised and less well understood than PVC.
A major issue for policy formulation in New Zealand is the effect of policies and regulations elsewhere. The EU WEEE and RoHS Directives are already creating considerable industry transformation, and will bring new materials to the market, as well as new industries and techniques for effectively managing the product stewardship and end-of-life implications of the Directives. They can also be expected to have effects outside Europe, with more toxic EEE being 'dumped' onto markets in countries with less developed policy and regulations.
Of the substances reviewed in this study, lead poses major risks because of the amounts occurring in WEEE and the toxicity potential. Mercury, cadmium and chromium VI (hexavalent chromium) are also of concern both because of their toxicity and leaching potential, and their persistence in the environment. BFRs are a complex issue, with proven potential human health effects associated with some compounds, and documented suspicions associated with most current major commercial substances. Similarly, PVC is a major concern, as well as being a contaminant in recycling streams.
The state of knowledge regarding the toxicity of WEEE components is developing, with still some way to go before confident and accurate predictions of effects on humans and the environment for all WEEE substances can be made. While some studies are several years old, they remain relevant until new evidence is developed, and significantly more research is needed into the toxicity potential of WEEE. Until then, it is prudent to take a precautionary approach; indeed, three well-established principles can be drawn upon to guide policy development in WEEE management:
- Precautionary principle; where theory or circumstantial evidence suggests damage potential exists, in the absence of fuller evidence, it is prudent to assume the worst case and legislate accordingly;
- Prevention is better than cure; it is cheaper in the long run to prevent risks and impacts from occurring rather than to concentrate entirely on cleaning up problems, so eco-design mechanisms to minimise WEEE generation is a logical approach;
- Polluter pays principle; those who create the risks should incorporate the costs of dealing with them into their operating costs, for example, through operating product stewardship programmes.