Ambient air is defined by its quality, which is governed both directly and indirectly by national, European Union and other international legislation as well as by recommendations from the World Health Organisation (WHO), which primarily focus on limiting and reducing the impact of human activities to ensure a clean environment and the good health of people.
By ‘ambient air’, we mean, in particular, the layer of air near the ground. At international level, it is agreed that ambient air quality is assessed up to two metres above the ground, which represents the main breathing zone for humans. This delimitation allows for the comparison of results across regional, national and international levels.
Efforts to reduce air pollution gained significant attention in the 1970s, with the greatest progress being made in reducing sulphur dioxide (SO2) emissions. However, as production and technology evolve, new pollutants are emerging, while at the same time, pollutant capture technologies are also improving. Efforts are being made to regulate emissions into the ambient air through the strict control of production technologies, including a system of environmental permits and specific measurements of pollutants. Coercive measures also include the taxation of the quantities of pollutants emitted into the air.
Main sources:
- Heat and power generation as well as other production processes, including agriculture
- Local sources of pollution, i.e. energy and technological devices, which are the source for a large part of global problems;
- Transport, especially car transport as one of the main contributors of urban air pollution;
- Local heating systems;
- Radars, radio stations and solariums as sources of electromagnetic fields and ultraviolet radiation;
- X-ray and radiation therapy equipment, various radioactive substances used in the industry and science as sources of ionising radiation.
Factors influencing ambient air include:
- Various chemical compounds, some of which are damaging to health while others are neutral in respect to people but not the environment (for example, carbon dioxide CO2)
- Noise
- Dust
- Ionising radiation, i.e. radiation having an impact on living tissues
- Non-ionising radiation, such as ultraviolet radiation
- Electromagnetic fields
- Light pollution
- Odour pollution
Impact of human activities
Main pollutants
In our daily lives, we are exposed to different pollutants, the most significant of which include:
- Sulphur dioxide (SO2)
- Nitrogen oxides (NOx)
- Non-methane volatile organic compounds (VOCs)
- Particulate matter (PM10) and fine particulate matter (PM2.5)
- Ammonia (NH3)
Air pollution has been classified as carcinogenic by the World Health Organisation (WHO). Air pollutants have varying toxicological properties that determine their potential risk to humans. The most hazardous are those which have carcinogenic, mutagenic or reproductively toxic properties.
Odour
Many pollutants in ambient air have distinct odours, which can be either pleasant or unpleasant. The odour of a substance can be detected at very low concentrations, but this does not necessarily indicate that it is harmful to humans at such levels.
When it comes to odour nuisance, we do not consider it a direct health risk, but rather a disturbance caused by the odoriferous substance. The term ‘exceedance of the disturbance level of the odoriferous substance’ is used in such a situation.
Noise
More recently, noise pollution has become an increasingly prevalent issue. Most people are affected by noise, primarily by traffic noise. Urbanisation and technological development are major contributors to noise pollution.
It is a local problem that can be addressed by local governments and residents through smart decisions aimed at preventing noise pollution.
Last updated: 28.07.2025
