Industry Knew for Decades That Microplastics Could Infiltrate Human Bodies

Internal chemical-industry records indicate that scientists had evidence decades ago that ingested plastic particles could move through the body. At a 1974 scientific meeting, German researcher Gerhard Volkheimer reported that PVC particles fed to dogs, pigs, and other animals reached the liver, brain, lungs, and other tissues within two hours. He also found that potato starch, which travels through the body in a similar way, appeared in the blood and breast milk of people who consumed it. Industry scientists repeatedly discussed the findings in later internal memos; a 1975 Union Carbide memo described the research as a frequently cited “horror story.” The documents, recovered through litigation, suggest companies were aware of potential risks, though an American Chemistry Council scientist argues that continued scientific debate is not equivalent to silence.

Microplastics are now reported in food, water, and air, as well as in human blood, lungs, placentas, urine, and breast milk. However, methods used to detect particles in tissue may produce errors, and some findings remain disputed. Evidence that certain plastic additives harm health is stronger than evidence about the effects of the particles themselves. Researchers are still working to establish how microplastics accumulate and what consequences they may have, so the historical findings raise concern without settling the current scientific questions.