According to CCTV reports (pictured): 2065438+June 3, 2003, 65438+2003, there was a serious haze weather in Beijing, with the pollution index reaching 900 and the PM2.5 above 500.

(2) Central heating in residential areas (the factory is abandoned and discharged, and the number of cars is limited);

(3) 3) The diameter of PM 2.5 is too small for ordinary masks to filter, so special masks (masks with activated carbon adsorption layer) should be brought.

Test analysis: (1) The air is heavily polluted, and the minimum pollution index is 300. (2) Mitigating the haze weather is mainly because PM2.5 in the air exceeds the standard. pm 2.5 refers to particles with a diameter less than or equal to 2.5 microns in the air. These particles come from the burning of a large number of fossil fuels, so it is necessary to reduce PM2.5 to slow down the haze weather. Therefore, it can reduce the emissions after central heating in residential areas and factory disposal, and reduce the number limit of single and even cars.