What are legacy pollutants?

Legacy pollutants are hazardous substances that have been widely used in the past and continue to persist in the environment due to their resistance to degradation. Examples include polychlorinated biphenyls (PCBs), certain heavy metals, and pesticides like DDT. Despite being banned or restricted, these pollutants can accumulate in ecosystems and pose risks to human health and wildlife over long periods. Their lingering presence often complicates environmental remediation efforts.