Answer: Pollutant
Step-by-step explanation:
Any undesired particle that is present in the environment is known as pollutant. These can be particulate matter or harmful gases that is present in the atmosphere.
These gases can be carbon dioxide( more than normal), carbon monoxide, sulfur dioxide, et cetera. Pollutants can be pollen grains, dirt and smoke which pollutes the environment.
Hence, undesired particles are known as pollutants.