Concentrations of nitrogen dioxide and total nitrogen oxides in ambient air do not exceed the prescribed limit values. Consequently, they are not harmful for human health and vegetation.

Air pollution with PM₁₀ was on average lower in 2020 than in previous years. The number of exceedances of the daily limit value for PM₁₀ (50 ug/m³) surpassed allowed number of exceedances (35) only at one monitoring site in mainland Slovenia, and at this monitoring site two out of thirty-six exceedances are due to desert dust, which according to legislation is considered as natural source of pollution and is not taken into account with prescribed quality standards.

Emissions of total ozone precursors in Slovenia decreased by 62 % in the period 1990 to 2020. Emissions of nitrogen oxides decreased by 66 %, carbon monoxide by 70 %, non-methane volatile organic compounds by 54 % and methane by 25 %. The reason is mainly the introduction of more stringent emission standards for motor vehicles. This measure contributed to a significant reduction in emissions of nitrogen oxides and carbon dioxide from road transport which is the main source of ozone precursors.

Heavy metal emissions in Slovenia significantly decreased between 1990 and 2020. This can be largely attributed to the implementation of the EU legislation, improved surveillance and use of the best available technology.