Air Quality Standards and Atmospheric Pollutants

Key Definitions in Air Pollution Control

Air pollution: The presence of materials or forms of energy in the air that imply a risk of serious harm or discomfort to persons and property of any nature.

Air Quality: The adaptation to air pollution levels, whatever the causes, that guarantee that the occurrence of materials in the air implies no serious discomfort, risk, or immediate or delayed damage to persons and property of any nature in the atmosphere.

Atmospheric Pollutants and Emissions

• Atmospheric Pollutant: Solid particles, liquids, or vapors and gases in the atmosphere that are not part of the normal composition of air or are present in abnormal quantities.
• Emission: The launching of materials into the air, either from a localized focus or resulting from photochemical reactions.
• Immission: The concentration of atmospheric pollutants at ground level, occurring temporarily or permanently.
• Background Pollution: The pollution that exists in a defined area before a new source of pollution is installed.
• Pollutant Source: A point source of pollutants in the atmosphere, especially any industrial installation or identified part of the same, which is poured to the outside environment through chimneys or other conduits.
• Plume: A broadcast composed only of gas or gases and aerosol particles emerging from a chimney.

Regulatory Thresholds and Air Quality Management

• Objective Value: A level set to prevent long-term adverse effects on human health and/or the environment, which must be achieved if possible at a determined time.
• Margin of Tolerance: The percentage of the limit value by which this may be exceeded under conditions of the framework directive.
• Agglomeration: An area characterized by a population concentration of 250,000 inhabitants, or when exceeding 250,000 inhabitants per km² population density, which justifies Member States assessing and monitoring ambient air quality.
• Total or Gross Deposit: The total mass of pollutants transferred from the atmosphere to surfaces in a given area during a determined period.
• Source: Resuspension of soil mineral matter, natural inputs from long-distance, etc.
• Carbon Monoxide: The most abundant air pollutant in the lower atmospheric layer, especially in large cities. It is a colorless, odorless, and tasteless gas, slightly lighter than air, and highly toxic.
• VOC: Volatile Organic Compounds present in the air in gaseous form under normal pressure and temperature.
• Alert Threshold: A level at which a short-duration exposure poses a human health risk for the general population and from which Member States must take immediate measures.
• Information Threshold: A level at which a short-duration exposure poses a risk to human health for groups especially at risk, and from which updated information is needed.
• Preliminary Evaluation: This consists of subdividing and classifying the territory into several areas comprising portions of territory with similar air quality.