Question

Any kind of substance released into the air from natural or human sources — discharge of gases, liquid droplets or solid particles, is called ............... .

Hint:

Tip: Anything harmful added to air → pollutant!

Answer 1

A pollutant is any substance released into the environment that can cause harm or contamination.
When gases, vapours, dust, liquid droplets or solid particles are discharged into the atmosphere, they degrade air quality.
Such substances may come from natural sources like volcanoes and dust storms or human activities like vehicle exhaust, factories, and burning fossil fuels.
Pollutants include CO₂, SO₂, NOx, particulate matter, and hydrocarbons.
They contribute to smog, acid rain, respiratory problems and global warming.
Residue and by-products are general terms, but when they enter the air and affect the environment, they are called pollutants.
Therefore, the correct answer is pollutant.