Last week, the World Health Organization released new data on air pollution in 1,600 cities worldwide.
The most striking conclusion? China gets way more attention for its air pollution, but India has a much bigger problem on its hands.
Put simply, if you live in a large Indian city, your lungs are taking in dangerous levels of air pollution on a daily basis.
Drawing on data collected between 2008 and 2013, the report listed the cities by the average amount of particulate matter in the air over the course of a year. When these tiny particles — smaller than 2.5 micrometers in diameter — are inhaled, they can settle into the lungs, increasing the long-term risk for lung cancer (each year, it's estimated that they cause 800,000 deaths worldwide).
In the new report, six of the top ten most polluted cities were in India, with Delhi leading the way. The figures show the average number of micrograms of these particles per cubic meter of air over the course of a year (for reference, the WHO considers 25 to be a safe limit):
Apart from the six Indian cities (shown in yellow), three more cities on this list are in nearby Pakistan (shown in blue), with Iran's Khoramabad the only city outside of South Asia in the top 10.
The worst American city in the report was Fresno, California, followed by a few other cities in California. This fits with the findings of a recent American Lung Association report that showed California, as a whole, features the country's worst air pollution.
A variety of factors contribute to air pollution, but it's mainly driven by the burning of gasoline, diesel, and coal for transportation and energy, along with other large-scale manufacturing processes.
So in response to China's high pollution levels, authorities recently introduced a plan to limit coal burning and vehicle use. But the report shows that even before this initiative, China's pollution paled in comparison to India's.
Beijing's data, for instance, came from 2010, and showed that the city averaged a count of 56 PM 2.5 over the course of a year. It's certainly not a great count, but for comparison, 25 Indian cities had higher levels of pollution during the time studied.
Update: it's worth noting that there is some controversy over air pollution data provided by the Chinese government. Independently-collected data, supplied by the U.S. embassy, suggests Beijing (and, presumably, other Chinese cities) have higher pollution rates than Chinese officials are willing to admit.
In 2011, for instance, the embassy's monitors averaged 99 PM 2.5: not nearly as high as Delhi, but high enough to have put Beijing in the top ten.
Correction: this story previously said that the report measured the number of particulates per cubic meter, not the number of micrograms of particulates per cubic meter.