Judgment of the Court (Seventh Chamber) of 3 February 2021.#European Commission v Hungary.#Failure of a Member State to fulfil obligations – Environment – Directive 2008/50/EC – Ambient air quality – Article 13(1) and Annex XI – Systematic and persistent exceedance of limit values for microparticles (PM10) in certain Hungarian zones – Article 23(1) – Annex XV – Exceedance period to be ‘as short as possible’ – Appropriate measures.#Case C-637/18.