Apart from two, Kota (58), Udaipur (59) and Alwar (61) are also among the polluted cities in the world. Air quality of 3,000 cities in 103 countries were surveyed by the WHO and is based on ground measurements of annual mean concentrations of particulate matter (PM 10 and PM 2.5).

Out of 122 cities in India where air pollution data was measured, Jodhpur recorded 101 micrograms per cubic meter as its annual PM 2.5 mean and is 13th most polluted. Jaipur with 100 micrograms per cubic meter is 15th in the country. Both cities annual mean is about 10 times the WHO standard of 10 micrograms per cubic meters. Including Kota, Udiapur and Alwar, Rajasthan has five cities in the top 25 populated cities in the country.

In terms of air pollution PM 2.5, is associated with more serious health impacts than PM 10. It consists of fine, particulate pollution which damages respiratory system more intensely than PM 10 which have coarse pollution particles.

"With rise in air pollution, the obstructive airway diseases are on the rise. Every year it is increasing 10-15% in Jaipur. It also causes allergic conjunctivitis and among children allergic rhinitis is the reason of air pollution," said Narendra Khippal, doctor and professor, institute of respiratory diseases, SMS Medical College.

Rajasthan being a tourist state has a pressing need to improve its air quality. Tourists worldwide these days plan their itinerary based on air quality index. With dismal record it is likely that state will lose on its foreign travelers to destinations with better air quality.

Global trends since 2008 show air pollution levels have gone up by 8% despite improvements in many cities.

WHO in its statement also said urban air pollution levels were lowest in high-income countries, with lower levels most prevalent in Europe, the Americas, and the Western Pacific Region but highest in low-and middle-income countries in eastern Mediterranean and South-East Asia Regions, with annual mean levels often exceeding 5-10 times WHO limits.