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Beryllium is a toxic bivalent element, steel gray, strong,
light-weight, primarily used as hardening agent in alloys. Beryllium has
one of the highest melting points of the light metals. It has excellent
thermal conductivity, is nonmagnetic, it resists attack by concentrated
nitric acid and at standard temperature and pressures Beryllium resist
oxidation when exposts to air.
Applications
Beryllium is used as an alloying agent in the production of
Beryllium-Copper. Thanks to their electrical and thermal conductivity,
high strenght and hardness, non magnetic properties, good resistance,
dimensional stability over a wide temperature range Beryllium-Copper alloys are used in many applications. A typical application of Beryllium-Copper alloys
is in the defense and aerospace industries.
Beryllium is also used in the field of X-ray detection diagnostic (it is
transparent to X-rays) and in the making of various computer equipment.
Beryllium in the environment
The Beryllium content on Earth crust is 2.6 ppm, in soil 6 ppm.
Beryllium in soil can pass into the plants grown on it, provided it in a
soluble form. Typical levels in plants vary between 1 and 40 ppb, too
low to affect animals which eat these plants.
Beryllium is found in 30 different minerals, the most important of which
are bertrandite, beryl, chrysoberyl, and phenacite. Precious forms of
beryl are aquamarine and emerald.
Beryllium is not an element that is crucial
for humans; in fact it is one of the most toxic chemicals we know.
It is a metal that can be very harmful when humans breathe it in,
because it can damage the lungs and cause pneumonia.
The most commonly known effect of Beryllium is called berylliosis,
a dangerous and persistent lung disorder that can also damage
other organs, such as the heart. In about 20% of all cases people
die of this disease. Breathing in Beryllium in the workplace is
what causes berylliosis. People that have weakened immune systems
are most susceptible to this disease.
Beryllium can also cause allergic reactions with people that are
hypersensitive to this chemical. These reactions can be very heavy
and they can even cause a person to be seriously ill, a condition
known as Chronic Beryllium Disease (CBD). The symptoms are
weakness, tiredness and breathing problems. Some people that
suffer from CBD will develop anorexia and blueness of hands and
feet. Sometimes people can even be in such a serious condition
that CBD can cause their death.
Next to causing berylliosis and CBD, Beryllium can also increase
the chances of cancer development and DNA damage.
Beryllium enters the air, water and soil as a
result of natural processes and human activities. It occurs
naturally in the environment in small amounts. Humans add
Beryllium through production of metal and combustion of coal and
oil.
Beryllium exists in air as very small dust particles. It enters
waterways during weathering of soils and rocks. Industrial
emissions will add Beryllium to air and wastewater disposals will
add Beryllium to water. It usually settles in sediment. Beryllium
as a chemical element occurs naturally in soils in small amounts,
but human activities have also increased these Beryllium levels.
Beryllium is not likely to move deeper into the soil and dissolve
within
groundwater.
In water, chemicals will react with Beryllium, causing it to
become insoluble. This is a good thing, because the
water-insoluble form of Beryllium can cause much less harm to
organisms than the water-soluble form.
Beryllium will not be accumulated in the bodies of fish. However,
some fruits and vegetables such as kidney beans and pears may
contain significant levels of Beryllium. These levels can enter
animals that eat them, but luckily most animals excrete Beryllium
quickly through urine and feces.
The uptake of Beryllium has consequences mainly for human health.
However, laboratory tests have indicated that it is possible for
Beryllium to cause cancer and changes of DNA with animals. So far
there is no field evidence to support these findings.
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