With pollution levels 30 times higher than deemed acceptable by the World Health Organization, the haze was dubbed the "airpocaylpse."
Flights were grounded, roads closed, and Chinese people are pushing back against lax environmental policy for the first time.
A new study found they have something to be furious about: air pollution was linked to 1.2 million premature deaths in 2010, nearly half of such deaths worldwide, the New York Times reported.
The data comes from the sprawling 2010 Global Burden of Disease Study published in December in The Lancet, a renouned medical journal, with specific data on Chinese statistics presented in Bejing Sunday.
"Ambient particulate matter pollution" is the fourth-leading factor leading to deaths in China, ranking seventh worldwide.
Researchers said pollution saps 25 million years of healthy life from China's population.
In response to outrage among its people, the Chinese government allowed media to write about the soaring levels of air pollution, and though the State council announced plans in February to introduce new fuel standards, oil and power companies owned by government often block any efforts toward tougher regulation.
According to the Financial Times, the "airpocalypse" may see an even more immediate effect: relocation companies are bracing for an exodus of expats leaving China because of the poor air quality.