- Non-biodegradable pollutants are substances that cannot be broken down by natural biological processes (like bacteria or fungi) into simpler, harmless substances. - DDT is a persistent organic pollutant (POP), meaning it remains in the environment for a very long time. - It accumulates in the tissues of living organisms (bioaccumulation) and becomes more concentrated as it moves up the food chain (biomagnification), posing risks to wildlife and potentially human health.