DDT (Dichloro-Diphenyl-Trichloroethane) is a synthetic chemical pesticide widely used in agriculture. It is highly persistent in the environment, meaning it does not break down easily through natural processes. This persistence allows it to accumulate in soil, water, and the fatty tissues of animals, leading to long-term ecological damage and health risks. Therefore, DDT is classified as a non-biodegradable pollutant.

Final Answer: Non-biodegradable pollutant