The AirParif hot-air balloon, which measures Paris' pollution levels at 300 meters in altitude is seen at sunrise from the suburb of Saint-Cloud, near Paris, France, December 8, 2016. [Photo/IC]

With its famous Eiffel Tower shrouded in a grayish haze and some tourists donning masks, the city also made all public transportation, residential parking and bicycle and electric car programs free.

"Cars are poisoning the air. We need to take preventive measures," said Herve Levife, a Paris transportation official.

The city also planned to step up its fight against chronic pollution by gradually banning the oldest and most polluting vehicles from the city center, he said.

"We want these bans to automatically take effect when the pollution exceeds a certain level, not have to negotiate them with the government each time," Levife added.