For each polluting substance, the maximum amount that can be discharged in air emissions is regulated. Maximum values ​​are generally set by the national environmental authority. The regulations can be validated for the entire national territory, or specific for some particular regions, due to their own characteristics.

Emission producing companies have the responsibility of complying with the prescribed regulations. It is the responsibility of the companies to obtain the respective operating permits.

Individual control over each of the emissions producers, and enforcing existing regulations, is extremely important. However it is not enough. Indeed, if in a certain area there are numerous industries that discharge atmospheric emissions, even respecting individual emission limits, air quality may be affected.

It is necessary to establish by law parameters that determine the maximum degree of admissible contamination. These parameters are of two types:

• - Limit values: indicate, for each substance, the maximum acceptable amount;

• - Guide value: indicate, for each substance, the maximum desirable amount;

The national environmental regulations establish who is responsible for monitoring air quality and the various parameters.

Industrial plants that produce particularly dangerous air emissions may even be restricted in relation to their location.

As far as thermal power plants are concerned, the legislation generally has two aspects:

• - Limit the emission of polluting substances; and,.

• - Limit the use of water.

These two objectives are achieved with complementary regulations, and refer particularly to thermoelectric plants and plants intended for heating.

Vehicles with internal combustion engines are mainly responsible for air pollution in urban areas.

The regulations that refer to this type of pollution can be divided into two groups:

• - Emergency measures: which include limits to establish alert and emergency situations. These limits may impose partial or total restriction of circulation.

• - Preventive measures: these can define the technical characteristics of the circulating vehicle models, and the definition of the individual emission parameters. The regulations regarding the quality of fuel, particularly with regard to sulfur content.

• - 2008 Directive on ambient air quality and a cleaner atmosphere in Europe (2008/50/EC).

• - 1996 Framework Directive on the assessment and management of ambient air quality (96/62/EC).

• - Gothenburg Protocol to the Convention on Long Range Transboundary Air Pollution of the United Nations Economic Commission for Europe (LRTAP).

• - EU National Emission Ceiling Directive (2001/81/EC)[7]​.

The expression "air quality" simply refers to open spaces, but air quality in closed spaces (for example, offices) is also important, since it influences people's health and the performance of workers.[8] Of course, in closed spaces the air pollutants are different, for example an excessive percentage of carbon dioxide, or formaldehydes.

More than half of the world's population depends on solid fuels (firewood, dung, etc.) for cooking, causing respiratory diseases that mainly affect women and children in developing countries. Every year, indoor air pollution causes around a million and a half deaths. Likewise, dependence on solid fuels aggravates deforestation rates and therefore contributes to global climate change.

The interventions available to reduce indoor air pollution levels are divided into those that change the source of pollution, those that improve the habitable environment and those that modify user behavior. Although various analyzes conclude that these interventions have achieved a reduction in indoor air pollution, there are few impact evaluations available on their cost-effectiveness, as well as their effectiveness in improving health, well-being and the environment.[9]​.

• - Ozone layer hole.

• - Air pollution.

• - Metropolitan Air Quality Index.

• - This work contains a translation derived from «Qualità dell'aria» from Italian Wikipedia, published by its editors under the GNU Free Documentation License and the Creative Commons Attribution-ShareAlike 4.0 International License.

• - AA.VV., "Inquinamento atmospheric - Legslazione e giurisprudenza.'" - Ed. AmbienteDiritto.it - ​​ISSN 1974-9562 [1] - In Italian..

For each polluting substance, the maximum amount that can be discharged in air emissions is regulated. Maximum values ​​are generally set by the national environmental authority. The regulations can be validated for the entire national territory, or specific for some particular regions, due to their own characteristics.

Emission producing companies have the responsibility of complying with the prescribed regulations. It is the responsibility of the companies to obtain the respective operating permits.

Individual control over each of the emissions producers, and enforcing existing regulations, is extremely important. However it is not enough. Indeed, if in a certain area there are numerous industries that discharge atmospheric emissions, even respecting individual emission limits, air quality may be affected.

It is necessary to establish by law parameters that determine the maximum degree of admissible contamination. These parameters are of two types:

• - Limit values: indicate, for each substance, the maximum acceptable amount;

• - Guide value: indicate, for each substance, the maximum desirable amount;

The national environmental regulations establish who is responsible for monitoring air quality and the various parameters.

Industrial plants that produce particularly dangerous air emissions may even be restricted in relation to their location.

As far as thermal power plants are concerned, the legislation generally has two aspects:

• - Limit the emission of polluting substances; and,.

• - Limit the use of water.

These two objectives are achieved with complementary regulations, and refer particularly to thermoelectric plants and plants intended for heating.

Vehicles with internal combustion engines are mainly responsible for air pollution in urban areas.

The regulations that refer to this type of pollution can be divided into two groups:

• - Emergency measures: which include limits to establish alert and emergency situations. These limits may impose partial or total restriction of circulation.

• - Preventive measures: these can define the technical characteristics of the circulating vehicle models, and the definition of the individual emission parameters. The regulations regarding the quality of fuel, particularly with regard to sulfur content.

• - 2008 Directive on ambient air quality and a cleaner atmosphere in Europe (2008/50/EC).

• - 1996 Framework Directive on the assessment and management of ambient air quality (96/62/EC).

• - Gothenburg Protocol to the Convention on Long Range Transboundary Air Pollution of the United Nations Economic Commission for Europe (LRTAP).

• - EU National Emission Ceiling Directive (2001/81/EC)[7]​.

The expression "air quality" simply refers to open spaces, but air quality in closed spaces (for example, offices) is also important, since it influences people's health and the performance of workers.[8] Of course, in closed spaces the air pollutants are different, for example an excessive percentage of carbon dioxide, or formaldehydes.

More than half of the world's population depends on solid fuels (firewood, dung, etc.) for cooking, causing respiratory diseases that mainly affect women and children in developing countries. Every year, indoor air pollution causes around a million and a half deaths. Likewise, dependence on solid fuels aggravates deforestation rates and therefore contributes to global climate change.

The interventions available to reduce indoor air pollution levels are divided into those that change the source of pollution, those that improve the habitable environment and those that modify user behavior. Although various analyzes conclude that these interventions have achieved a reduction in indoor air pollution, there are few impact evaluations available on their cost-effectiveness, as well as their effectiveness in improving health, well-being and the environment.[9]​.

• - Ozone layer hole.

• - Air pollution.

• - Metropolitan Air Quality Index.

• - This work contains a translation derived from «Qualità dell'aria» from Italian Wikipedia, published by its editors under the GNU Free Documentation License and the Creative Commons Attribution-ShareAlike 4.0 International License.

• - AA.VV., "Inquinamento atmospheric - Legslazione e giurisprudenza.'" - Ed. AmbienteDiritto.it - ​​ISSN 1974-9562 [1] - In Italian..