What is the primary cause of pollution as defined in environmental science?

The primary cause of pollution in environmental science is defined as the addition of harmful substances through human activity. This definition highlights the anthropogenic nature of pollution, where human actions—such as industrial processes, agricultural practices, waste disposal, and urban development—introduce harmful substances into the environment. These substances can include chemicals, heavy metals, plastics, and other pollutants that exceed the environment’s capacity to naturally assimilate or neutralize them, leading to degradation of air, water, and soil quality and posing risks to ecosystems and human health.

The focus on human activity is crucial because it distinguishes pollution from natural processes. While natural substances may be released into the environment, they do not inherently cause pollution unless their concentrations or forms exceed ecological tolerances, which is usually a result of human influence. The essence of pollution lies in the harmful effects caused by these substances, making the human contribution a central theme in environmental science discussions surrounding pollution management and mitigation.