What does it mean to start the second-level emergency for the weather warning with heavy environmental pollution?

Heavy air pollution is divided into four warning levels, as if every region is different. Generally, the order from light to heavy is early warning level 4, early warning level 3, early warning level 2 and early warning level 1, which are marked with blue, yellow, orange and red respectively, and early warning level 1 (red) is the highest level.

Warning level 4 (blue):

It is predicted that serious pollution will occur in the future 1 day.

Emergency measures: remind children, the elderly and susceptible people such as patients with respiratory tract, cardiovascular and cerebrovascular diseases to reduce outdoor sports. Advocate the public and units that discharge air pollutants to consciously take measures to reduce pollutant discharge, such as increasing the frequency of sprinkling water and cleaning roads on construction sites; Sewage disposal units should take further measures to reduce pollutant emissions.

Warning level 3 (yellow):

It is predicted that serious pollution will occur in the future 1 day or last for 3 days.

Emergency measures: in addition to health protection reminding measures and suggested pollution reduction measures, compulsory pollution reduction measures are added, such as increasing the frequency of road cleaning and washing according to the key roads determined by the road cleaning and washing sub-plan during heavy air pollution to reduce traffic dust pollution; Effective dustproof measures such as covering and sprinkling water must be taken to reduce the excavation scale of earthwork construction and building demolition.

Secondary warning (orange):

It is predicted that severe pollution or serious pollution will appear alternately in the next three days.

Emergency measures: stop the demolition of earthwork and buildings at the construction site, and stop the transportation of dust-prone vehicles such as muck trucks and gravel trucks; According to the list determined by the sub-plan for industrial enterprises to stop production or limit production during the period of heavy air pollution, the relevant enterprises will be implemented with measures to stop production or limit production and reduce emissions by 30%; On the basis of the existing "no release" and "no burning" scope, fireworks and firecrackers and open-air barbecues are prohibited within the city.

It is suggested that primary and secondary schools and kindergartens should stop outdoor sports such as physical education class, recess exercise and sports meeting.

Warning level (red):

It is predicted that there will be serious pollution in the next three days.

Emergency measures: On the basis of the orange warning of "stop production, stop work, no release and no burning", the motor vehicles in the city will run with single and even numbers, of which 30% of all official vehicles in Beijing will stop driving with single and even numbers, and the bus operation department will increase the capacity guarantee.