What is the difference between heavy pollution weather warning and smog warning?

These two kinds of early warning are two sets of release mechanisms. The release unit of smog warning is the Provincial Meteorological Observatory, and the release unit of heavy polluted weather is the Municipal Pollution Control and Haze Reduction Office.

The standards published by the two are also different. Haze is a pure weather phenomenon. The published reference indicators are visibility, PM2.5 and relative humidity. Release is to inform the whole society.

AQI (Air Quality Index) is a reference index for early warning of heavily polluted weather. In addition to PM2.5, AQI also includes five other reference standards, such as sulfur dioxide, nitrogen dioxide, inhalable particulate matter (PM 10), ozone and carbon monoxide, so the concentration of PM2.5 does not necessarily represent AQI index.

Different from issuing smog warning to the society, heavy pollution weather warning belongs to government behavior and has the executive power of the government. In addition to informing the society, all departments are also required to implement corresponding emergency measures and bear the responsibilities caused by failure to implement them.