Pollution in many Chinese cities will peak from Monday to Wednesday, and the amount of PM2.5 particles in the air will reach a density of 500 micrograms per cubic meter.
Vehicle use restrictions, construction site closures, measures to reduce factory emissions, and class cancellations at kindergartens and primary schools have been announced.
China's Ministry of Environmental Protection has dispatched 13 inspection teams to six provinces and municipalities to supervise the implementation of contingency plans.