Immission is the impact of radiation, light, sound or noise on living beings. These are emissions generated directly or indirectly by people or their technical equipment; for example, the excessive volume in discotheques, the impairment caused by machine noise, exhaust fumes or electrosmog, odor nuisance, disturbing light immission or the impairment caused by radiation. Immissions are directly related to the environment and its ecosystems.
To ensure that immissions do not pose a health hazard, the International Commission for Non-Ionising Radiation Protection( ICNIRP) has defined immission limits that are provided with a safety factor.
The immission values are highest directly at the immission source, where they exceed the immission limit values many times over. For example, the immission limit is exceeded many times over in the immediate vicinity of a mobile phone antenna. If the immission limits are not exceeded, there is no health risk. At a greater distance from the immission source, the limit value is referred to as the installation limit value.
The system limit values are far below the hazard potential. They are defined for each installation and must not affect the health of persons staying in the installation area. Plant areas include schools, homes, hospitals, exhibition halls, train stations, etc.
In Germany, the impairment of immissions is regulated by the Federal Immission Control Ordinance (BImSchV).