Microplastics in Humans: What the Science Really Says

Analytical limits still hamper detection and quantification of micro- and nanoplastics in tissues and food, making standardized assays an urgent research priority.

Published on Feb. 21, 2026

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In recent years, reports have described microplastics found in various human tissues, including blood, placenta, testes, and brain. However, the scientific papers describing these contaminations have often been criticized for using inadequate methodologies. Even today, researchers are navigating a young field riddled with analytical and interpretive difficulties.

Why it matters

Concerns about micro- and nanoplastics (MNPs) emerged in the early 2000s due to their accumulation in the oceans, ingestion by marine organisms, and possible ecological effects. After 2010, potential risks to human health were raised because MNPs enter the food chain, especially through consumption of shellfish and fish.

The details

Plastic is a product of modern chemistry that has pervaded nearly every aspect of industrial production and daily life. Plastics are polymers, and their chemical bonds can break due to mechanical forces, physical processes, or chemical interactions, producing fragments that become progressively smaller until they form microplastics and nanoplastics. MNPs have been found in various human tissues, but the scientific papers describing these contaminations have often been criticized for using inadequate methodologies.

  • In the early 2000s, concerns about MNPs emerged due to their accumulation in the oceans and ingestion by marine organisms.
  • After 2010, potential risks to human health were raised because MNPs enter the food chain, especially through consumption of shellfish and fish.

The players

Marco Crescenzi

A physician and former research director at the Italian National Institute of Health in Rome who conducted extensive research at Washington University in St. Louis, the National Institutes of Health in Bethesda, Sapienza University of Rome, and the Regina Elena National Cancer Institute in Rome.

World Health Organization (WHO)

The organization that concluded the available data are insufficient to determine whether exposure to nano- and microplastics is associated with any direct or indirect characteristic pathology.

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What’s next

The World Health Organization recommends not ignoring the potential health effects of microplastics and nanoplastics and calls for the development of appropriate methods for investigation and experimentation.

The takeaway

While reports have described microplastics in various human tissues, the scientific evidence is still limited, and researchers are facing significant analytical and interpretive challenges in this young field of study. More standardized methods and further research are needed to better understand the potential risks of microplastics and nanoplastics to human health.