Electronic equipment contains metals and other materials that can be
hazardous to human health and the environment if they are not properly
Cadmium - found in chip resistors, infrared detectors, and
Cadmium can accumulate in, and negatively impact the kidneys. Cadmium is
persistent, bioaccumulative, and toxic. The principal exposure pathway
is through respiration and through our food.
Lead - found in glass panels in computer monitors and in
lead soldering of printed circuit boards
Lead can cause damage to the central and peripheral nervous systems,
blood systems, and kidneys in humans. Lead has also been shown to have
negative effects on the development of children's brains. Lead can
accumulate in the environment and have a detrimental effect on plants,
animals, and humans. Consumer electronics may be responsible for 40% of
the lead found in landfills. The principal pathway of concern is lead
leaching from landfills and contaminating drinking water supplies.
Mercury - found in thermostats, position sensors, relays
and switches (e.g., on printed circuit boards), discharge lamps, and
batteries. It is also used in medical equipment, data transmission,
telecommunications, and mobile phones.
When mercury makes its way into waterways, it is transformed into
methylated mercury in the sediments. Methylated mercury accumulates in
living organisms and travels up the food chain. Methylated mercury can
cause brain damage. The principal exposure pathway is through our food.
Hexavalent Chromium or Chromium VI - can be used to protect
against corrosion of untreated and galvanized steel plates
Chromium VI can damage DNA and has been linked to asthmatic bronchitis.
The major pathways are through landfill leachate or from fly ash
generated when materials containing Chromium VI are incinerated.
Brominated Flame Retardants - found on printed circuit
boards, components such as plastic covers and cables as well as plastic
covers of televisions
Although less is known about BFRs than some other contaminants of
concern, research has shown that one of these flame retardants,
Polybrominated Diphenylethers (PDBE) might act and an endocrine
disrupter. Flame retardant Polybrominated Biphenyls (PBB) may increase
cancer risk to the of the digestive and lymph systems. Once released
into the environment through landfill leachate and incineration they are
concentrated in the food chain.
Plastic - Because manufacturers use many different types of
plastic in electronic equipment, it is the most challenging to recycle.
These plastics often include contaminants such as metal screws and
inserts, coatings and paints, foams, and labels. Currently, plastics
from electronic equipment are both difficult and costly to sort for
single resin feedstocks markets and there are limited markets for the
mixed plastics stream. Also, plastics can be treated with brominated
flame retardants, making them harder to recycle and possibly dangerous
to those exposed to them.
Additionally, electronics are made with valuable resources such as
precious metals, engineered plastics, glass, and other materials—all of
which require energy to manufacture. When equipment is thrown away,
these resources cannot be recovered and additional pollution will be
generated to manufacture new products out of virgin materials.
EPA. "Ecycling". Frequent Questions.
(18 April, 2006)