Maximum allowable concentration

Maximum permissible concentration (MPC) maximum number of harmful substances per unit volume (air, water, other fluids) or weight (food), the receipt of which is the body's natural ways during the working day at work or a long time in other conditions does not lead to pathological changes in health status and does not cause adverse genetic changes in the offspring.

Maximum permissible concentration (MPC) - minimum values of concentrations of harmful substances in the water or in the air, which the daily effects on the body for indefinitely long time does not cause any pathological changes or diseases to be detected by modern means of research. At a substantiation of MPC is based on the experimental data, materials of dynamic observation of the state of health of groups of people exposed to various substances concentration in the production process, and computational methods. This, along with the respiratory (main) by take into account the possibility of receipt of substances through the skin and the digestive tract.
MPC of substances in water open water bodies and water sources set taking into account the possible impact of toxic substances on the General sanitary conditions of water basins, the organoleptic properties of water and health.
When determining the allowable concentrations of substances in the atmospheric air into account the impact of harmful substances to people of all ages (including patients) throughout life. MAC radioactive substances defined on the basis of biological data, taking into account the absorption, distribution, excretion, energy and half-life of the isotope, solubility compounds, dispersion of substances and the degree of toxicity.
Special attention is paid to the determination of the critical organ (see), the accumulation of radioactive substances which causes the most severe defeat the whole organism.
Maximum permissible concentration of radioactive substances in water and air Express in curies per liter (Curie/l)for toxic substances in the air in mg/m3, in the water in mg/L. MAC radioactive isotopes in air and water in a thousand or more times (in terms of weight) is less than for other toxic substances. Especially low MPC in the air of working premises (10-15-10-14 Curie/l) is set for long-lived α-emitting isotopes able to selectively focus in the individual organs and slowly stand out from the body.
MPC levels into account when designing technological processes of various industries, equipment, wastewater treatment plants, etc. to ensure safe working conditions and living standards.
Cm. also Doses of ionizing radiation.