The same week Beijing issued its first-ever emergency red alert because of dangerous levels of smog, cardiologist Dr. Naresh Trehan released a photo showing the devastating effects of air pollution in Delhi, India.
The Indian city's pollution levels are estimated to be roughly one and a half times worse than in Beijing, where a single day of normal breathing can bring in the equivalent of 40 cigarettes-worth of carcinogens.
Using the hashtag #DelhiChokes, Trehan showed India Today the difference between a healthy lung and a lung belonging to a 52-year-old man who spent 10 years living in Delhi.
"This stark contrast tells the whole story," Trehan told India Today. "It's saying that look if you are being exposed to this kind of pollution for prolonged periods of time, this is what it will look like."
As Tech Insider previously reported, smog levels and quantities of charcoal-based particulate in India are so bad that white shirts will gather a yellow tinge over the course of a single day.
While Trehan's photo hasn't been verified as that of someone living in highly polluted conditions (and there's no way to prove that this is typical for a longtime Delhi resident), a raft of other images back up the claim. Upon autopsy, smokers' lungs have been routinely found to contain the same jet-black traces of tar seen in Trehan's photo.
Air pollution in China and India has become a severe problem because of massive industry growth over the last decade. The two countries have taken insufficient steps to reduce the emissions produced by their coal-burning factories. The result isn't pretty.