Heavy metals are metals, whose density is larger or alike to 5 g/cm All other metals are light alloys.

In the technology also alloys with high density are in such a way designated.

Among them rank among other things: the precious metals as well as bismuth, iron, copper, lead, zinc, tin, nickel, cadmium, chrome and uranium.

The dismantling of heavy metals accompanies frequently with a high load of the soils. In places in the resin and in the winner country on the soils loaded by ore mining industry for example specific Pflanzengesellschaften were formed (so-called Azonale vegetation). There the so-called Galmeipflanzen trains heavy metal lawns.

RutherfordiumDubniumSeaborgiumBohriumHassiumMeitneriumDarmstadtiumRoentgenium

Use

Heavy metals are used within many ranges, mostly however for the metal refinement. Thus the selected materials receive a special characteristic. The following areas of application are today forbidden due to their health-endangering effect:

- Lead in PVC and drinking water pipelines

- Cadmium in the Kosmetik, plant protection and PVC

- Copper, iron and zinc for drinking water pipelines

- Mercury in wood preservatives, impregnate-openly, Antifoulingfarben as well as for water purification

Within these ranges heavy metals are further used:

- Chrome and nickel for steel

- Lead for accumulators (=aufladbare Batterieen), sheaths, pigments, alloys as well as with the radiation protection

- Mercury in small quantities in fluorescent tubes and energy energy-savings lamp, in the apparatus technology and to the amalgam Plombenherstellung

- Cadmium for accumulators (nickel cadmium and silver cadmium), as corrosion protection for iron and similar metals (by electrolytic separation or Vacuum vaporization produced cadmium coats already protect in a thickness of 0.008 mm from corrosion.), cadmium pigments and cadmium soap as Stabilisaoren for PVC, cadmium alloys and in the nuclear technology as braking and control rods in reactors (cadmium 113 has a particularly large capture cross section for neutrons).

Vitally necessary

Some heavy metals are in small traces vital for humans, them as trace elements are then designated. In addition belong: Chrome, iron, Fluor, Germanium, Iod, Kobalt, Kupfer, Lithium, Mangan, Nickel, Selen, Vanadium, Zink and Zinn.

Health endangerment

All heavy metals are health-endangering for the human organism to deadly, since they cannot be diminished. They are taken up usually over the food chain and arrive in such a way into the human body.

Lead

Lead possesses a cumulative effect and works with the admission by food and breathing air already in slight traces as chronic poison. It enriches itself in bone, teeth and in the brain and impairs the operability of the nervous system. Particularly children are endangered, them often show intelligence, learning and concentration disturbances. Also the immune defense comes with lead poisonings to damage comes it to a increased A carcinogenic effect of lead is not to be excluded.

Cadmium

Cadmium and its connections are already in small concentrations poisonous. It proved in the bioassay as carcinogenic and is hereditarygood and fruit-damaging. The body of an adult contains approx. 30 mg cadmium, without it is needed for the structure by body substances, it belonged to the not-essential elements. The oral admission of soluble cadmium salts can cause a vomiting and disturbances in the Verdauungsdrakt, liver damages and cramps. The inhalation of cadmium steams causes provoking the respiratory system and headache. Chronic poisonings express themselves by the loss of the smell ability, yellow colouring of the tooth necks, blood poverty and eddy pain, in advanced stage by marrow damages and Osteoporose. Cadmium is increased come into disrepute since the occurrence of the often deadly ending Itai Itai illness into Japan, which goes with heavy skeleton changes. The enrichment of cadmium in the liver and particularly in the kidney is particularly precarious. With smokers about twice as high contents were determined of cadmium as with nonsmokers. The average load with cadmium by smoking amounts to 0.002 mg to 0.004 mg per day. With the food humans daily about 0.01 mg to 0.035 mg cadmium nimmmt up. According to WHO the critical limit value is about 0,01 mg per kg of The biological radioactive half-life in humans amounts to about 10 to 35 years.

Mercury

Mercury is taken up over the lung to the body. It provokes the breath and digesting ways, can to vomiting with belly pain lead and also damage to kidneys and central nervous system is possible.

Copper

Copper causes weakness, a vomiting and inflammations in the digestive tract when swallowing. Acute poisonings are rare with humans, since inevitably vomiting is caused. For babies increased concentrations in the drinking water represent a danger. Copper in the waste of combustion plants favours the emergence of strongly poisonous polychlorierter dioxins and Furane as catalyst.

Articles in category "Heavy metal"

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