LONDON - Amsterdam has banned cruise ships - and it's not just another policy to stop swarms of tourists descending on the city centre.

Amsterdam has famously introduced a number of measures to reduce tourist numbers, including pleading with British men to stay away. And while tourism does come into the cruise ship ban - the Dutch capital is a city of just under one million people yet attracts about 20 million a year - the council also cited air pollution as a key factor.

Ilana Rooderkerk of the D66 party, which co-runs the council, said: "The polluting cruise is not in line with Amsterdam's sustainable ambitions. Cruise ships in the city center also do not fit in with the task of combating mass tourism.

"The climate will not wait. In other words, it's time for action. Amsterdam sails better without the cruise."

EU data suggest Amsterdam has high levels of tiny air pollution particles - known as PM2.5 - relative to its size, with 9.5 μg/m3 in a city of 996,000 people.

On the other hand, Madrid, the third largest city in Europe and five times bigger than Amsterdam with 5.1 million people, has PM2.5 of 9.2 μg/m3.

For context, the World Health Organization (WHO) has an annual average guideline of 5 μg/m3 for PM2.5.

Amsterdam and Madrid are far from the worst cities for dirty air, with London the fourth most polluted in Europe (13.3 μg/m3 according to 2019 data, though this was before the Ultra Low Emission Zone for polluting vehicles came into force). Milan tops the list with 19.7 μg/m3.

The below graphic shows the PM2.5 ratings of all European cities* with more than one million people.

PM2.5 is capable of penetrating deep into the lungs and entering the bloodstream, causing cardiovascular, cerebrovascular (stroke) and respiratory impacts. There is emerging evidence that particulate matter impacts other organs and causes other diseases as well.

Public Health England, now the UK Health Security Agency, previously estimated that up to 43,000 people a year are dying in the UK because of air pollution and that it could cost the country as much as £18.6 billion by 2035 unless action is taken.