| Electrical and electronic equipment are made up of a multitude of
components, some containing toxic substances which can have an adverse
impact on human health and the environment if not handled properly.
Often, these hazards arise due to the improper recycling and disposal
processes used.
For example, Cathode Ray Tubes (CRTs) have high content of carcinogens
such as lead, barium, phosphor and other heavy metals. When disposed
carefully in a controlled environment, they do not pose any serious
health or environmental risk. However, breaking, recycling or
disposing CRTs in an uncontrolled environment without the necessary
safety precautions can result in harmful side effects for the workers
and release toxins into the soil, air and groundwater.
Another dangerous process is the recycling of components containing
hazardous compounds such as halogenated chlorides and bromides used as
flame-retardants in plastics, which form persistent dioxins and furans
on combustion at low temperatures (600-800°C) Copper, which is present
in printed circuit boards and cables, acts a catalyst for dioxin
formation when flame-retardants are incinerated. The PVC sheathing of
wires is highly corrosive when burnt and also induces the formation of
dioxins. A study on burning printed wiring boards in India showed
alarming concentrations of dioxins in the surroundings of open burning
places reaching 30 times the Swiss guidance level.
Landfilling e-waste, one of the most widely used methods of disposal,
is prone to hazards because of leachate which often contains heavy
water resources. Even state-of-the-art landfills which are sealed to
the long-term. Older landfill sites and uncontrolled dumps pose a much
greater danger of releasing hazardous emissions. Mercury, Cadmium and
Lead are among the most toxic leachates. Mercury, for example, will
leach when certain electronic devices such as circuit breakers are
destroyed. Lead has been found to leach from broken lead-containing
glass, such as the cone glass of cathode ray tubes from TVs and
monitors. When brominated flame retarded plastics or plastics
containing cadmium are landfilled, both PBDE and cadmium may leach
into soil and groundwater.In addition, landfills are also prone to
uncontrolled fires which can release toxic fumes.
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