Maximum admissible hazardous contaminant levels in communities ambient air, registered during a certain period of time, should have neither direct nor indirect harmful effect on human organism, remote consequences for the present and future generations included, should not decrease man’s capacity for work, longevity and should not deteriorate man’s good general condition. Maximum admissible hazardous contaminant levels in communities ambient air are deteriorated as maximum single time levels, average round-the-clock and average annual levels according to Annex 1. In the course of assessment of atmospheric air pollution by some simultaneously found hazardous substances, it is admitted to determine the impact of their total quantity according to Annex 2. A combined impact of atmospheric pollutants means the penetration into the organism of different hazardous substances by one and the same pathway simultaneously or in a period of time, determined for the respective substances. A complex impact of atmospheric pollutants means the penetration into the organism of one and the same substance by different pathways simultaneously or during a period of time determined for the respective substance.