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Finished Computer
Composition
As described eariler,
the manufacturing and materials used in computers involve some harmful
and toxic chemicals. 
Many of these chemicals and elements make up the final composition
of the computer. These elements in a computer and their recylability
are described below.
Lead: Lead makes
up about 6% of the total weight of a computer and is used in the
CRT of monitors and to solder (a method of connecting) components
on printed circuit boards. Lead has a number of detremental health
impacts especially on the brain and nervous system. Many other industries
have been phasing lead out of their process. About 40% of the lead
found in landfills comes from electronics.
Using the estimates
of number of obsolote computers in the next few years and weight
above (See Beginning of Section), about 1.2 billion pounds of lead
will result from obsolete computers by 2004.
Cadmium: Semiconductors,
chip resistors, and old CRT monitors contain cadmium. Cadmium can
be absorbed through food or respiration accumulating in the kidneys.
Mercury: Mercury
is used in batteries (laptops) and printed circuit boards in addition
to a variety of electrical equipment. It can cause brain damage.
Plastics: Plastics
constitute about 22% of a computer. The largest use of plastic comes
from PVC which has now been generally phased out by most computer
manufacturers. Unfortunately, an estimated 4 billion pounds of plastic
are part of computers that will become obsolete.
Flame Retardants:
Polybrominated
Biphenyls (PBBs), a mixture made up
in part of Bromine, is used to decrease the flammability in several
parts of a computer including the printed circuit boards and cables.
This
substance can potentially be carcinogenic.
End of Section: Back to Beginning
Composition of a Desktop Personal Computer
Based on a typical desktop computer, weighing ~60 lbs. |
Table presented in: Microelectronics
and Computer Technology Corporation (MCC). 1996.
Electronics Industry Environmental Roadmap. Austin, TX:
MCC.
HTML Table from Silicon Valley Toxic Coalition |
| Name |
Content
(% of total weight) |
Weight of material
in computer (lbs.) |
Recycling Efficiency
(current recyclability) |
Use/Location |
| Plastics |
22.9907 |
13.8 |
20% |
includes organics,
oxides other than silica |
| Lead |
6.2988 |
3.8 |
5% |
metal joining, radiation
shield/CRT, PWB |
| Aluminum |
14.1723 |
8.5 |
80% |
structural, conductivity/housing,
CRT, PWB, connectors |
| Germanium |
0.0016 |
< 0.1 |
0% |
Semiconductor/PWB |
| Gallium |
0.0013 |
< 0.1 |
0% |
Semiconductor/PWB |
| Iron |
20.4712 |
12.3 |
80% |
structural, magnetivity/(steel)
housing, CRT, PWB |
| Tin |
1.0078 |
0.6 |
70% |
metal joining/PWB,
CRT |
| Copper |
6.9287 |
4.2 |
90% |
Conductivity/CRT,
PWB, connectors |
| Barium |
0.0315 |
< 0.1 |
0% |
in vacuum tube/CRT |
| Nickel |
0.8503 |
0.51 |
80% |
structural, magnetivity/(steel)
housing, CRT, PWB |
| Zinc |
2.2046 |
1.32 |
60% |
battery, phosphor
emitter/PWB, CRT |
| Tantalum |
0.0157 |
< 0.1 |
0% |
Capacitors/PWB,
power supply |
| Indium |
0.0016 |
< 0.1 |
60% |
transistor, rectifiers/PWB |
| Vanadium |
0.0002 |
< 0.1 |
0% |
red phosphor emitter/CRT |
| Terbium |
0 |
0 |
0% |
green phosphor activator,
dopant/CRT, PWB |
| Beryllium |
0.0157 |
< 0.1 |
0% |
thermal conductivity/PWB,
connectors |
| Gold |
0.0016 |
< 0.1 |
99% |
Connectivity, conductivity/PWB,
connectors |
| Europium |
0.0002 |
< 0.1 |
0% |
phosphor activator/PWB |
| Titanium |
0.0157 |
< 0.1 |
0% |
pigment, alloying
agent/(aluminum) housing |
| Ruthenium |
0.0016 |
< 0.1 |
80% |
resistive circuit/PWB |
| Cobalt |
0.0157 |
< 0.1 |
85% |
structural, magnetivity/(steel)
housing, CRT, PWB |
| Palladium |
0.0003 |
< 0.1 |
95% |
Connectivity, conductivity/PWB,
connectors |
| Manganese |
0.0315 |
< 0.1 |
0% |
structural, magnetivity/(steel)
housing, CRT, PWB |
| Silver |
0.0189 |
< 0.1 |
98% |
Conductivity/PWB,
connectors |
| Antinomy |
0.0094 |
< 0.1 |
0% |
diodes/housing,
PWB, CRT |
| Bismuth |
0.0063 |
< 0.1 |
0% |
wetting agent in
thick film/PWB |
| Chromium |
0.0063 |
< 0.1 |
0% |
Decorative, hardener/(steel)
housing |
| Cadmium |
0.0094 |
< 0.1 |
0% |
battery, glu-green
phosphor emitter/housing, PWB, CRT |
| Selenium |
0.0016 |
0.00096 |
70% |
rectifiers/PWB |
| Niobium |
0.0002 |
< 0.1 |
0% |
welding allow/housing |
| Yttrium |
0.0002 |
< 0.1 |
0% |
red phosphor emitter/CRT |
| Rhodium |
0 |
|
50% |
thick film conductor/PWB |
| Platinum |
0 |
|
95% |
thick film conductor/PWB |
| Mercury |
0.0022 |
< 0.1 |
0% |
batteries, switches/housing,
PWB |
| Arsenic |
0.0013 |
< 0.1 |
0% |
doping agents in
transistors/PWB |
| Silica |
24.8803 |
15 |
0% |
glass, solid state
devices/CRT,PWB |
Source Figure: Dell.com. Does not specifically imply that Dell computers
contain these materials.
Health Information: Silicon Valley Toxic Coalition
|