Arsenic

Arsenic (Arsenicum), As, is a chemical element V of groups of periodic system of elements of D. I. Mendeleyev. Serial number 33, the atomic mass (weight) 74,9216, temperature melting point of about 817 degrees (at 36 ATM.), in water insoluble, in the air slowly oxidized. In the form of organic compounds arsenic contained in trace in the tissues of plants and animals. Oxides of arsenic and salts arsenic (arsenite) and arsenic (arsenate) acids are used in medicine and industry.
Arsenic radioactive. In medicine and biology predominantly use arsenic-73 (As73), arsenic-74 (As74) and arsenic-76 (As76). As74 in the process of radioactive decay (T1/2=17,sut.) emits beta-particles (see Beta-radiation) with energy 0,69-1,53 MeV and-quanta (see Gamma rayswith energy 0,596 and 0,635 MeV; As76 (T1/2=26,5 hour.) - beta-particles with an energy of 0.36-2,96 MeV and-quanta with energy 0,549-2,053 MeV.
Radioactive arsenic is used to study the distribution in the body of animals and humans, and to determine ways and rate of excretion from the body.
Isotopes of arsenic used for detection of brain tumors, as entered in the blood preparations tend to accumulate in increased amounts in the zone of tumor growth (see Radioisotope diagnostics, Scanning).
Significant accumulation of arsenic in the epidermis allowed to use radioactive arsenic for the treatment of skin manifestations of infection (see) and leukemia (see Leukemia).
Working with isotopes of arsenic should be conducted in specialized radiological departments and radiological laboratories with the implementation of antiradiation protection (see).
The sanitary standards adopted in the USSR, the average annual allowable concentration As76 in the water and open water is 1.9·10-8 Curie/l, in the air of working premises - 1·10-10 Curie/L.

  • Arsenic as industrial poison
  • Drugs arsenic