Microplastics enter the human body primarily through the ingestion of contaminated food and water, inhalation of airborne particles, and limited dermal absorption [1, 2].

This accumulation is a growing concern because the body's natural expulsion mechanisms are ineffective against particles of this size [1, 3]. As these materials persist in the environment, they move through the global food chain and water supplies, making exposure nearly universal [2, 4].

Plastics break down over time into smaller fragments known as microplastics and nanoplastics [1, 3]. Many of these particles are smaller than a sesame seed, while some are far smaller than the width of a human hair [2]. Because of their minute size, these fragments can bypass the body's standard filters and lodge within tissues [1].

While the presence of these particles is widely documented, some scientists question the reliability of current research. Some researchers said the findings regarding particles in brains, arteries, and placentas may be flawed [3]. However, other reports describe established mechanisms that allow these plastics to enter the body and remain there [1].

Microplastics are now found globally in wildlife and human environments [2, 4]. The process begins when larger plastic waste degrades into microscopic pieces that contaminate the air and water [1, 2]. Once ingested or inhaled, these particles resist the biological processes intended to eliminate foreign objects [1, 3].

“the body's natural expulsion mechanisms are ineffective against particles of this size”

The persistence of microplastics in human tissue suggests a long-term shift in biological exposure. While a scientific debate continues regarding the severity of the health impacts, the inability of the human body to expel these particles means that current environmental plastic pollution is creating a permanent internal footprint in the global population.