The poor air quality in Delhi and Beijing has drawn global attention over the past month. While the Indian capital has decided to introduce an experimental odd-even number plate policy to limit vehicular emissions, its Chinese counterpart has closed factories, limited car use and closed schools in the wake of two "red alerts" in December over smog levels.


In 2014, the World Health Organisation declared Delhi to be the most polluted city on the planet.
Source: Adnan Abidi/Reuters



Beijing has been shrouded under a toxic haze for most of December.
Source:  Reuters


But these capital cities aren't alone. The onset of winter has led to high air pollution levels in cities across the globe, as emissions from vehicles and industries fail to rise above cold air.

Tehran
On Sunday, air pollution levels in Iran’s capital Tehran were more than double the acceptable level. Earlier in the week, authorities took the drastic step of closing schools for three days in the vicinity of the capital and older people were asked to stay indoors.

Two football matches in the country’s top league were also postponed because of the poor air quality, with Tehran’s environment authority asking people to avoid all sporting activity.


Source: Atta Kenare/AFP


The problem is not restricted to Tehran as high air pollution levels have been recorded in the provinces of Qazvin, Qom and Esfahan.

Authorities estimate that vehicles are responsible for 80% of the air pollution in the city and some parliamentarians have blamed imported petrol for the polluted air.

Last December, almost 400 people were hospitalised with heart and respiratory problems caused by heavy pollution in Tehran, with nearly 1,500 others requiring treatment, the health ministry said. 

Rome
Shrouded in harmful fog for several days in December, Italian cities Milan and Rome have decided to restrict car use. Milan has banned cars, motorcycles and scooters for six hours a day for three days starting December 28. A special "anti-smog" all-day public transport ticket has been introduced.

In the capital, Rome, cars with odd-numbered plates were banned for nine hours on Monday. On Tuesday, cars with even-numbered plates will be restricted.



Source: Tiziana Fabi/AFP


In 2012, Italy had the most pollution-related deaths in Europe at 84,000, according to the European Environment Agency.

Earlier this month, the mayor of San Vitaliano, just outside Naples, banned the use of wood-fired pizza stoves. The stoves must be fitted with special pollution filters before they can be used.

Sarajevo
Severe air pollution in Sarajevo, the capital of Bosnia and Herzegovina, has prompted authorities to ask drivers to use their motor vehicles less, while city dwellers have been told to cut their movements in the mornings and evenings.

On December 23, dense fog and polluted air lowered the visibility to less than 20 metres. Schools were closed and flights were cancelled. Authorities say it is the longest period of bad weather in decades.


Source: Elvis Barukcic/AFP


After an increase of medical interventions for pulmonary and heart ailments, health authorities advised citizens to reduce time spent outside or to wear face masks when they leave indoor spaces.