This review aims to summarize the existing knowledge on the environmental and occupational health risks of waste electrical and electronic equipment (WEEE) recycling and other end-of-life options. Hazardous substances present in WEEE, including heavy metals (e.g., mercury, cadmium, lead, etc.), flame retardants (e.g., pentabromophenol, polybrominated diphenyl ethers (PBDEs), tetrabromobisphenol-A (TBBPA), etc.) and other chemicals may pose significant human and environmental health risks, if improperly managed. The substances are found in complex combinations in numerous electrical and electronic devices.
It describes the hazards associated with WEEE treatment in developing countries. WEEE recycling operations in developing countries are mostly unregulated and employ rudimentary techniques. WEEE recycling operations in several locations in China, India and Ghana have been particularly well investigated. The potentially hazardous recycling practices include manual disassembly of WEEE with little regard to its hazardous content, recovery of solder and chips from printed circuit boards (PCBs) by heating them, acid extraction of metals from complex mixtures, melting and extruding plastics, and burning of plastics to isolate metals.