Fog is caused by water droplets in the air. But, Smog - Smog is Smoke + Fog.

It is a sign of severe air pollution.

Look at the image below of a city in China, notice the effect of smog in the atmosphere.

Effect of Smog.png

 

Let's discuss the differences between Fog and Smog

Fog Smog
Fog is caused by water droplets in the air Smog is made up of Smoke and Fog
It reduces visibility, but breathing in fog causes no harm.  Breathing in Smog can cause Eye Irritation, Asthma and decreases Lung's Breathing Capacity
Color of fog is white Color of Smog is usually blackish, but may change depending on other pollutants in the atmosphere 

Fog vs Smog - Teachoo.jpg

  1. Class 8
  2. Chapter 18 Class 8 - Pollution of Air and Water

About the Author

Davneet Singh's photo - Teacher, Computer Engineer, Marketer
Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.