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. 

The emission of primary particles, smaller than 10 µm (PM₁₀), particles smaller than 2.5 µm (PM_2.5) and all total suspended particles (TSP) have decreased in the period 2000 – 2021 in Slovenia by 21 %, 29 % and 20 %. The main source of emissions of particulate matter are households, mainly due to use of biomass for domestic heating.

In Slovenia, total emissions of the pollutants that contribute to acidification and eutrophication have decreased by 81 % between 1990 and 2021. Emissions of SO_x have decreased by 98 %, NO_x by 66 % and NH₃ by 22 %. The emissions of sulphur oxides, nitrogen oxides and ammonia were in 2021 below the prescribed target values. Slovenia also met its emission reduction commitments compared to the year 2005.

In Slovenia, emissions of persistent organic pollutants (polychlorinated biphenyl, polycyclic aromatic hydrocarbons, hexachlorobenzene, dioxins and furans) decreased between 1990-2021, primarily due to targeted legislation, improved control and use of best available technologies.

Emissions of total ozone precursors in Slovenia decreased by 62 % in the period 1990 to 2021. Emissions of nitrogen oxides decreased by 66 %, carbon monoxide by 70 %, non-methane volatile organic compounds by 54 % and methane by 26 %. 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.