Speaking to TOI, US embassy deputy minister counselor for economic, environment, science and technology Samuel Kotis said high levels of air pollution was a growing concern among expatriates.

"Air pollution affects everyone because we all breathe the same air. Its adverse impact on health is definitely cause for concern. As a father, I am worried about my son who is 16. On days when the pollution level is very high in Delhi, I ask him to stay indoors. I am sure parents in Kolkata would be concerned as well because there are days when the air here is more polluted than Delhi," Kotis said.

The Global Burden of Disease Report, considered the gold standard in global epidemiology, assessed that ambient air pollution was responsible for 630,000 premature deaths a year, or more than one death per minute. The World Health Organization 2014 report on air pollution lists Kolkata among polluted cities. Delhi tops the chart globally.

A recently published report by researchers from the University of Chicago, Harvard and Yale found that ambient air pollution is on average shaving three years of life expectancy for people in India. In a metro, the loss will be higher. Also, in a study commissioned by Central Pollution Control Board, scientists found that particulate pollution caused irreversible reduction in children's lung function. "As a parent myself, and one who is only in Delhi for a relatively short period of time, that is a conclusion that is very troubling to say the least," the diplomat remarked.

The US embassy in Delhi and four consulates in Kolkata, Mumbai, Hyderabad and Chennai independently monitor air quality 24x7 and upload the data on its websites. Though the consulate in the city is located in a relatively traffic free zone (there is restriction on movement of cars on Ho Chi Minh Street due to security concerns) and the air monitoring station is located next to a lawn in the consulate compound, the air quality is poor except in summer when heat and rain contribute to its improvement.

Kotis said many American cities were facing a similar problem in the 1960s and 1970s as high pollution made the cities polluted, dirty and unattractive.

"Just think of smog-laden Los Angeles of the 1960s and 70s and compare it to the much cleaner skies you can experience there to know what a difference concerted, well-planned and well-executed long-term action can make. Indian cities, including Kolkata, can also transform themselves into clean urban centers with growing economies and healthy populations," he pointed out.

But if Kolkata fails to address the concern, it would not only have to bear the incremental cost of an ailing population, companies operating out of the city may have to pay more to executives. That is a complete reversal of the current situation where salaries in Kolkata are lower than Mumbai or Dehi.

"Despite an attractive package, many may not consider an assignment in a polluted city, particularly those who have school-going children," Kotis said, pointing out that addressing the issue of air pollution now can also mitigate climate change for future generations.