First grade indexes

Second grade indexes

Third grade indexes

Symbol

The Comprehensive Index of Fog-Haze Risk

The pollutants in the air

Particulate concentration

$f_1$

Average annual SO₂ concentration

$f_2$

Average annual NO₂ concentration

$f_3$

Industrial Pollutant emissions

Total industrial emissions

$f_4$

Industrial sulfur dioxide emissions

$f_5$

Industrial smoke and dust emissions

$f_6$

Transportation pressure

Private vehicle ownership/Road mileage

$f_7$