Pollution occurs when harmful substances are introduced into the ecosystem, leading to the degradation of environmental quality. These harmful substances, known as pollutants, can be both organic and inorganic in nature. Organic pollutants include substances like volcanic ash, while human activities often contribute pollutants such as industrial waste, garbage, and factory runoff. These pollutants negatively impact the quality of air, water, and land, disrupting ecosystems and posing significant risks to both environmental and human health.