http://www.nytimes.com/2016/11/11/health/india-air-pollution-health.html
In December 1873, London was blanketed for a week in a yellow fog so thick that people could not see their feet. “Ladies & gentlemen,” Mark Twain said in a public lecture at the time, “I hear you, & so know that you are here — & I am here, too, notwithstanding I am not visible.”
Some 780 people died and 50 prize cattle on display at the Smithfield Club panted, wheezed and eventually died of asphyxia. Still, it took 83 more years of noxious air before the country passed the Clean Air Act in 1956.
This history, described in “London Fog: The Biography,” is a lesson in just how difficult it is for governments to put public health first when it comes into conflict with economic development, the political power of industry and even the polluting habits of their people.
Air pollution is the fourth top cause of death globally, after poor diet, high blood pressure and smoking, with more than one in 10 deaths linked to it in 2015, according to the Global Burden of Disease, a vast data trove compiled by more than 2,000 researchers led by the Institute for Health Metrics and Evaluation at the University of Washington.
The group estimates that roughly 6.5 million people died from both indoor and outdoor air pollution in 2015. Two million of them died in India. Deaths from outdoor air pollution have risen to 4.2 million in 2015 from 3.5 million in 1990.