Taking a deep breath in New Delhi may be more difficult, as spikes in smog levels have even sparked comparisons with Beijing’s low air quality.
India's air pollution is getting worse, according to the 2014 Yale University Environment Performance Index (EPI). One of the ways pollution is measured is by tiny airborne particles smaller than 10 micrometers, called PM10s.
"A bottom performer on nearly every policy issue included in the 2014 EPI, with the exception of forests, fisheries and water resources, India's performance lags most notably in the protection of human health from environmental harm," read a statement issued by Yale.
This winter, levels of PM 10 have routinely bounced around 400 micrograms per cubic meter the past several months. That's well above the World Health Organization's recommended limit of 20 and ranks four times the city's legal limit of 100. In 2011, the average level rose to about 280, according to the Hindustan Times.
Pollution can exacerbate chronic lung ailments, and there is mounting evidence it can lead to coronary diseases and inflammation.