Italy, Germany, France and Britain have reportedly failed to respect regulations on smog. As a result, they will be referred to the European Court of Justice.

The case against Italy regards particulate matter (PM10) levels being above the permitted threshold, reported the Italian news agency ANSA.

In a separate report, The Local noted that 25 Italian cities have already exceeded the European Union’s standards for air quality, which specify that cities should have no more than 35 “bad air” days – when levels of PM10 pollution exceed micrograms per cubic metre of air – per year.

Last year, Turin already had 66 “bad air” days, followed by Cremona with 58 and Padova with 53. Venice has had 52 and Milan 50.

Almost all of the worst affected cities were in the north of Italy.

The situation has been exacerbated by months of extremely low rainfall and high temperatures well into autumn, which look set to continue until at least the end of this week.

Smog levels way above safe limits in northern Italy

It is however an improvement on 2015, when more than half of Italian cities – 48 of them – exceeded the EU’s air pollution limits, according to Legambiente. Frosinone was the worst offender that year with 115 “bad air” days.

Several Italian cities, especially in the north, have imposed restrictions on driving in certain zones and at certain times in a bid to lower emissions.

As noted by The Local, Italy has not yet set a target for banning the sale of new diesel vehicles – unlike EU members France and UK.