A man walks along trees on a heavy haze winter day in central Beijing

A man walks along trees on a heavy haze winter day in central Beijing, January 12, 2013. Microscopic pollutant particles in the air have killed some 8,600 people prematurely in 2012 and cost $1 billion in economic losses in four Chinese cities, according to a study by Beijing University and Greenpeace. The study of pollutant levels of PM2.5, or particles smaller than 2.5 micrometres in diameter, in Beijing, Shanghai, Guangzhou and Xi’an called for PM2.5 levels to be cut to World Health Organisation guidelines, which would reduce deaths by over 80 percent, the China Daily newspaper reported. REUTERS/Jason Lee (CHINA — Tags: ENVIRONMENT BUSINESS)