Microplastics are everywhere – and raising urgent health questions, new study finds
image: Growing concerns over ingested microplastics in humans
Credit: Shaoyan Zhao, Lifen Yao, Long Zhu, Jiao Dong, Gerald A. LeBlanc & Lihui An
Microplastics, tiny bits of plastic less than 5 millimeters in size, are now found in our air, food, water, and even inside the human body, according to new research led by scientists from China and the United States. The study, published in Carbon Research, urges scientists and policymakers to take immediate steps to understand and address potential health risks linked to widespread plastic pollution.
Researchers examined microplastics in a wide range of human tissues, including blood, liver, placenta, and even breast milk. The main types of microplastics observed were polyethylene, polypropylene, polystyrene, and PET. Most of these plastics originate from the breakdown of larger plastic items through environmental processes like weathering and thermal degradation.
While laboratory experiments have shown that microplastics can harm the intestines, disrupt reproductive systems, and provoke immune responses in test animals, the concrete health impacts on people remain unclear. Recent evidence suggests that smaller microplastics, especially those less than 20 micrometers, are capable of penetrating human tissue. Once inside, they may trigger inflammation, cellular injury, and even changes at the genetic level.
A major concern highlighted by the authors is that microplastics can act as carriers for other toxic substances. Their surfaces, especially after environmental aging, become more likely to absorb pollutants which may then be delivered into the body through ingestion. This “Trojan horse” effect is being actively studied by toxicologists.
Despite the risks, there are significant knowledge gaps. Scientists still do not know the exact levels of microplastics that are harmful or which organs are most vulnerable. The study stresses the importance of improving detection methods and building a reliable framework for evaluating human exposure to microplastics.
Understanding how ingested microplastics are absorbed, fragmented, and distributed throughout the body is crucial. The authors recommend developing sensitive technologies for monitoring microplastics in human tissues and excretions, which would help clarify health risks and guide safer policies on plastic production and use.
The researchers call for better communication of microplastic hazards so that the public and lawmakers can take meaningful action to reduce plastic pollution. Raising awareness may promote rational consumption and motivate global policy changes to tackle this emerging threat.
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Journal reference: Zhao, S., Yao, L., Zhu, L. et al. Growing concerns over ingested microplastics in humans. Carbon Res. 4, 1 (2025). https://doi.org/10.1007/s44246-024-00164-7
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About Carbon Research
The journal Carbon Research is an international multidisciplinary platform for communicating advances in fundamental and applied research on natural and engineered carbonaceous materials that are associated with ecological and environmental functions, energy generation, and global change. It is a fully Open Access (OA) journal and the Article Publishing Charges (APC) are waived until Dec 31, 2025. It is dedicated to serving as an innovative, efficient and professional platform for researchers in the field of carbon functions around the world to deliver findings from this rapidly expanding field of science. The journal is currently indexed by Scopus and Ei Compendex, and as of June 2025, the dynamic CiteScore value is 15.4.