Plastic pollution harms animals through entanglement, ingestion, and chemical contamination across marine, freshwater, and terrestrial environments, representing a pervasive global welfare threat.
Plastic pollution causes welfare harm to animals across an enormous range of scales and mechanisms. At the visible end: entanglement causes drowning, strangulation, and limb loss; large plastic ingestion causes gut blockage, starvation, and internal injury. At the microscopic end: microplastic ingestion may interfere with digestion and deliver associated chemical contaminants that disrupt hormones and immune function. For sea turtles that ingest plastic bags they mistake for jellyfish, the death from pseudosatiation is slow and distressing — a full stomach that provides no nutrition while blocking real food. The welfare case for reducing plastic pollution aligns almost perfectly with environmental conservation goals, making this an area where welfare and ecological arguments reinforce each other powerfully.