The list of toxic components in computers includes:
• Computer circuit boards containing heavy metals such as lead & cadmium
• Computer batteries containing cadmium
• Cathode ray tubes with lead oxide & sometimes barium
• Brominated flame-retardants used in 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 burned
• Mercury switches
• Mercury in flat panel screens
• Poly Chlorinated Biphenyls (PCBs) present in older capacitors & transformers

from:

Poison PCs and Toxic TVs (document força antic)
http://svtc.org/wp-content/uploads/ppc-ttv1.pdf