In the period 2002-2017, the highest exposure to ozone concentrations were detected in the Primorska region in summer where air quality measuring stations in Koper and Nova Gorica detected highest ozone concentrations in ambient air. There are some differences from year to year in a level of ozone exposure due to meteorological conditions in the warm half of the year and other regional characteristics.

The measured concentrations of nitrogen dioxide and total nitrogen oxides in outdoor air do not exceed the prescribed limit values, so these two pollutants are not harmful human health and vegetation.

In 2018 PM₁₀ pollution was comparable to years before. The level of concentration is highly dependent on weather conditions. Exceedences of the daily limit values occur especially in the cold part of the year due to heating and due to meteorological conditions, which are extremely unfavourable in winter.  In 2018 at six measuring sites, PM₁₀ concentration were above the allowed annual number of 35.  The annual limit value for PM₁₀ as well as for the PM_2,5 was not exceeded at any measuring sites.

Emissions of total ozone precursors decreased by 52 % in the period 1990 to 2016. Emissions of nitrogen oxides decreased by 48 %, carbon monoxide by 64 %, non-methane volatile organic compounds by 52 % and methane by 14 %. 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.