Disposing of Computers is Hazardous
In addition to the recent evidence of worker exposure to flame retardants, the environmental risks posed by landfilling and burning are also significant. In particular, when computer waste is landfilled or incinerated, it poses contamination problems in leachate to water sources and toxic air emissions.
The Hazards of Incinerating Computer Junk
The stream of Waste from Electronic and Electrical Equipment (WEEE) contributes significantly to the heavy metals and halogenated substances contained in the municipal waste stream.(28) Because of the variety of different substances found together in electroscrap, incineration is particularly dangerous. For instance, copper is a catalyst for dioxin formation when flame-retardants are incinerated. This is of particular concern as the incineration of brominated flame retardants at a low temperature (600-800°C) may lead to the generation of extremely toxic polybrominated dioxins (PBDDs) and furans (PBDFs).(29)
Significant quantities of PVC are contained in WEEE(30) which makes the flue gas residues and air emissions particularly dangerous.(31)
The introduction of WEEE into incinerators results in high concentrations of metals, including heavy metals, in the slag, in the fly ash, the flue gas and in the filter cake. In this context, more than 90% of the cadmium put to an incinerator is found in the fly ash and more than 70% of the mercury in the filter cake.(32)
Municipal incineration is the largest point source of dioxins into the US and Canadian environments and among the largest point source of heavy metal contamination of the atmosphere.
Some producers send their electroscrap to cement kilns for use as an alternative to fuel. Smelting can present dangers similar to incineration. Indeed, there have been concerns expressed that the Noranda Smelter in Quebec, where much of the North American electroscrap is sent, is producing dioxins due to the residual presence of PVC or other plastics in the scrap. (33) Noranda has denied that their smelter presents a pollution hazard.
The Hazards of Landfilling Computer Junk
It has become common knowledge that all landfills leak. Even the best "state of the art" landfills are not completely tight throughout their lifetimes and a certain amount of chemical and metal leaching will occur.(34) The situation is far worse for older or less stringent dump sites.
Mercury will leach when certain electronic devices, such as circuit breakers are destroyed. The same is true for PCBs from condensors. When brominated flame retarded plastic or cadmium containing plastics are landfilled, both PBDE and the cadmium may leach into the soil and groundwater. It has been found that significant amounts of lead ions are dissolved from broken lead containing glass, such as the cone glass of cathode ray tubes, when mixed with acid waters which commonly occur in landfills. (35)
Not only the leaching of mercury poses specific problems. The vaporization of metallic mercury and dimethylene mercury, both part of WEEE, is also of concern. In addition, uncontrolled fires may arise at the landfills and this could be a frequent occurrence in many countries. When exposed to fire, metals and other chemical substances, such as the extremely toxic dioxins and furans (TCDD -Tetrachloro-dibenzo-dioxin, PCDDs, PBDDs and PCDFs - polychlorinated and polybrominated dioxins and furans) from halogenated flame retardant products and PCB containing condensers can be emitted.
The Hazards of Recycling Computer Junk
Recycling of hazardous products has little environmental benefit – it simply moves the hazards into secondary products that eventually have to be disposed of. Unless the goal is to reddesign the product to use non-hazardous materials, such recycling is a false solution.
The list of e-toxic components in computers include:
- computer circuit boards containing heavy metals like lead & cadmium
- computer batteries containing cadmium
- cathode ray tubes with lead oxide & barium
- brominated flame-retardants used on printed circuit boards, cables and plastic casing.
- Poly Vinyl Chloride(PVC) coated copper cables and plastic computer casings that release highly toxic dioxins & furans when burnt to recover valuable metals
- mercury switches
- mercury in flat screens
- Poly Chlorinated Biphenyl’s (PCB’s) present in older capacitors & transformers
Due to the halogenated substances found in plastics, both dioxins and furans are generated as a consequence of recycling the metal content of WEEE. Halogenated substances contained in WEEE, in particular brominated flame-retardants, are also of concern during the extrusion of plastics, which is part of plastic recycling. Due to the risk of generating dioxins and furans, recyclers usually abstain from recycling flame-retarded plastics from WEEE. However, due to the lack of proper identification of plastic containing flame retardants , most recyclers do not process any plastic from WEEE.(38)
Environmental problems during the recycling of WEEE are not only linked to halogenated substances. Hazardous emissions to the air also result from the recycling of WEEE containing heavy metals, such as lead and cadmium.(39) These emissions could be significantly reduced by means of pre-treatment operations. Another problem with heavy metals and halogenated substances in untreated WEEE occurs during the shredding process. Since most WEEE is shredded without proper disassembly, hazardous substances, such as PCB contained in capacitors, may be dispersed into the recovered metals and the shredder waste.(40)
E-Waste Exports – an unknown, dangerous and secretive activity.
It is difficult to find data on the amount of computer scrap leaving the US for countries such as Taiwan and China. This is because of past bad publicity and the fact that producers will sell scrap to recyclers and not bother finding out the final destination and fate of their end of life product.
The export of scrap is profitable because the labor costs are cheap and regulations are lax compared to US law. A pilot program that collected electronic scrap in San Jose, CA estimated that it was 10 times cheaper to ship CRT monitors to China than it was to recycle them in the US. (41)
The overwhelming majority of the world’s hazardous waste is generated by industrialized market economies. Exporting this waste to less developed countries has been one way in which the industrialized world has avoided having to deal with the problem of expensive disposal and close public scrutiny at home.
In 1989 the world community established the Basel Convention on the Transboundary Movement of Hazardous Waste for Final Disposal to stop the industrialized nations of the OECD from dumping their waste on less developed countries. The USA, however, has declined to sign the Convention.
Electrical & electronic scrap, including computers, are considered hazardous according to the Basel Convention Technical Working Group (TWG) because they can contain many hazardous components including PCB’s, mercury, lead & cadmium. Many of these hazardous substances are contained within individual components within the like circuit boards, batteries, switches and capacitors. WEEE will remain regulated under these provisions unless it can be proved it does not contain hazardous constituents.
In 1994 parties to the Basel Convention, now over 60 countries, agreed to an immediate ban on exports of hazardous waste destined for final disposal in non-OECD countries. It was clear however; that this was not enough to stop the transport of waste which countries claimed was being exported for recycling purposes.
Seventy-seven non-OECD countries, and China, pushed heavily for a ban on the shipping of waste for recycling. As a result, the Basel Ban was adopted, promising an end to the export of hazardous waste from rich OECD countries to poor non-OECD countries for recovery operations by December 31st 1997. The USA has declined to participate.
The US has lobbied Governments in Asia to establish bilateral trade agreements to continue dumping their hazardous waste after the Basel Ban came into effect on January 1st 1998. The amount of computer scrap exported from the USA will continue to grow as product obsolescence increases.
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