Maximum concentration limit is the maximum concentration of impurity in the atmosphere referred to certain time of averaging which at periodic impact or on an extent of all human life does not render neither on it, nor on environment in general harmful action (including separate consequences).
Maximum Permissible Concentration (MPC) of impurity. The main fizichchesky characteristic of impurity of the atmosphere is concentration – weight (matter m in units of volume (m * air under normal conditions. Defines concentration of impurity physical, himichchesky, etc. types of impact on the person and environment and serves as key parameter when rationing the content of impurity in the atmosphere.
Additional resources of environment protection apply on transport and mobile power installations. These are mufflers, sazheolovitel, netralizator of the fulfilled DVS gases, mufflers of noise of compressor installations and GTDU, vibroinsulators of rail transport, etc.
for example loss of space dust, or short-term spontaneous, for example forest and steppe fires, eruptions of volcanoes, etc. Level of pollution of the atmosphere natural sources is background and changes a little eventually.