Material

Main applications in computer production

Environmental/health Impacts

Plastics including PVC

Cabling, computer housings

Various cancers; endocrine system disruption (PVC emits highly toxic dioxins)

Lead

Soldering of printed circuit boards and other components; glass panels in CRT monitors

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. Accumulates in environment and has high acute and toxic effects on plants, animals, and micro-organisms Damage to nervous system, blood

Barium

Vacuum tubes in CRT monitors

Short-term exposure to barium can lead to brain swelling, muscle weakness, damage to the heart, liver and spleen. Long-term effects of chronic exposure not yet known.

Beryllium

Used for thermal conductivity

Recently identified as human carcinogen. Exposure can cause lung cancer and skin diseases.

Cadmium

SMD chip resistors, infrared detectors, semiconductors, older models of CRTs; also used as plastic stabilizer

When plastics containing cadmium are landfilled, can leach into groundwater. Acute and chronic toxic compound which accumulates in human body, esp. in kidneys. Can be absorbed either through respiration or ingested through food.

Hexavalent Chromium

Mostly phased out, but still some limited use as corrosion protector and decorative or hardener for steel housings

Highly toxic material which can pass easily through cell membranes; causes strong allergic reactions (e.g. asthmatic bronchitis) even in small concentrations. May also cause DNA damage. Contaminated wastes can leach from landfills

Selenium

Used in rectifiers and printed wiring boards

Exposure to high concentrations of selenium compounds cause selenosis, the symptoms of which are hair loss, nail brittleness, and neurological abnormalities.

Mercury

Sensors and switches on printed circuit boards, batteries, switches/housing, printed wiring boards, tubes in flat panel screens

Mercury is released when electronic devices that contain it are destroyed – such as in, or on the way to, landfills. The vaporization of metallic mercury and dimethylene mercury is also a possibility. Both are highly toxic – methylated mercury causes chronic brain damage. Inorganic mercury is transformed into methylated mercury when introduced into natural water systems, where it concentrates in sediment. Easily accumulates in living organisms, especially fish.

Arsenic

‘Doping’ agents in transistors and printed wiring boards

Chronic exposure to arsenic can lead to various diseases of the skin and decrease nerve conduction velocity. It can also cause lung cancer and can often be fatal.

PCBs (Poly-chlorinated biphenyls)

Used in capacitors and transformers (older equipment only)

PCBs affect the immune, hormone, nervous, and enzyme systems of the body and therefore have impacts on almost every organ. PCBs are considered by health agencies as a known carcinogen for animals and a probable carcinogen for humans.