China's environment watchdog issued its most comprehensive and toughest plan to control and in some regions reduce air pollution by the year 2017, setting stricter limits on the levels of PM 2.5 particles.

The Airborne Pollution Prevention and Control Action Plan (2013-17) will be the second plan to tackle pollution in the past two years and will be backed by 1,700 billion yuan ($277 billion) in total investments from the central government.

It will give priority to regions that have heavy air pollution and high levels of PM 2.5 — particulate matter that is 2.5 microns or less in diameter and that harms the respiratory system more than larger particles.

The new plan specifically targets North China, particularly Beijing, Tianjin and Hebei province. The plan's goal by 2017 is for a 25 percent reduction in air emissions from 2012 levels in that region.