immissions

Immisions refer to the transfer of pollutants, contaminants, or other harmful substances from the atmosphere into the environment through precipitation, such as rain, snow, sleet, or fog. This process is distinct from emissions, which are the release of pollutants directly into the air from sources like industrial facilities, vehicles, or burning fossil fuels. Immisions can significantly impact ecosystems, human health, and infrastructure.

The primary forms of immissions are wet immissions, which occur when pollutants dissolve in rainwater, and dry immissions, where particles and gases settle onto surfaces without precipitation. Wet immissions often carry higher concentrations of acids, such as sulfuric and nitric acids, formed from sulfur dioxide and nitrogen oxides reacting in the atmosphere. These acids can lead to acid rain, which damages forests, lakes, and buildings, and can also harm aquatic life by altering water chemistry.

Dry immissions involve the deposition of particulate matter and gases like ozone and fine dust, which can settle directly onto soil, vegetation, and human settlements. These particles can exacerbate respiratory issues, particularly in vulnerable populations, and contribute to smog formation. Immisions are a key component of atmospheric pollution and are regulated in many countries to mitigate their environmental and health effects.

Understanding and controlling immissions requires monitoring atmospheric conditions, identifying sources of pollutants, and implementing measures such as emission controls, scrubbers, and reforestation to reduce their impact. International agreements, like the United Nations Framework Convention on Climate Change, also play a role in addressing transboundary immissions that cross national borders.