be disposed with this stream in 2005.MercuryMercury is used in printed circuit boards, batteries, switches and printed wiring boards. While the percentage found in the average PC is only 0.002%, 17 based on the total number of disposed PCs estimated in Canada in 2000, this represents 0.5 tons of mercury. Mercury is also found in the fluorescent lamps that were previously used tobacklight laptop computer screens, but have now been replaced with xenon.Based on the prediction that 47,821 tons of PCs and monitors will be disposed in 2005 and assuming that the average composition of this equipment will not changesignificantly by that year, 1.1 tons of mercury will be disposed with this stream in 2005.Brominated Flame RetardantsBrominated flame retardants are used to reduce the flammability of plastics in electronic products. They are most typically used in circuit boards, connectors, plastic covers and cables 18. There are many types of BFRs (more than 60), some of which are more toxic than others. The European Union Waste Electrical and Electronic Equipment (WEEE) Directive has chosen to focus its efforts on the two classes of BFRs that pose the highest cause for concern, that is, polybrominated biphenyls (PBB) and polybrominated diphenyl ethers (PBDE). These are the compounds that are most likely to form dioxins and furans during the incineration process. When these compounds are burned, brominated materials are converted into polybrominated dibenzo furans (PBDF) and polybrominated dibenzo dioxins (PBDD) and can be released into the atmosphere.19Therefore, when plastics containing BFRs, in particular PBB and PBDE, are extruded during the recycling process or when they are incinerated for disposal, hazardous compounds may be released into the environment.Polyvinyl Chloride Plastic (PVC)Although most computer moldings are now made using ABS plastic, PVC has been widely used in computer cabling and housings. There is a risk that dioxins and f...
