Assertion: Pollution is always caused by human activities. Reason: Pollution is not different from contamination.

Pollution may be defined as an undesirable change in the physical, chemical or biological characteristics of our air, water and land that may or will harmfully affect human lives or other organism. Pollution can be natural or man made. Natural pollution comes from volcanic eruptions. Most of the pollution is man-made. Contamination occurs due to the presence of harmful organisms or their products or undersirable products in a desirable product causing disease or discomfort, to the organism who consume it. Therefore pollution and contamination are two different things.