They report a concerning relationship between micro and nanoplastic (MNP) concentrations in damaged tissues and links with multiple health conditions.

Plastic usage soared from 1.5 million metric tons in the 1950s to nearly 390.7 million in 2021. With the increased use in consumer products came elevated microscopic plastic pollution circulating in soil and waterways, eventually accumulating in the environment, food webs and human tissues.

Consistent methods to pinpoint and quantify MNPs in human tissues are lacking. Reliable data linking MNPs to human diseases are necessary for assessing potential risks and developing mitigation measures.

In the study, "Mapping micro(nano)plastics in various organ systems: Their emerging links to human diseases?" published in TrAC Trends in Analytical Chemistry, investigators collected 61 available research articles for MNP detection in human tissues, plus 840 articles on MNP toxicological mechanisms.

Data came from spectroscopy, microscopy, and pyrolysis-gas chromatography/mass spectrometry investigations to identify polymer types in different tissues. Toxicological studies employed cell models and animal experiments to examine oxidative stress, inflammatory responses, and related signaling pathways.

The studies documented particles detected in skin, arteries, veins, thrombi, bone marrow, testes, semen, uterus, and placenta. MNPs were found in the digestive system, from saliva to feces, liver, and gallstones.

Within the respiratory system, MNPs were everywhere, including lung tissue, with microscopic fibers common in bronchoalveolar lavage fluid and sputum.

Positive correlations emerged between particle abundance and specific disorders, such as inflammatory bowel disease, thrombosis, cervical cancer, and uterine fibroids.

Toxicological tests showed possible MNP-triggered oxidative stress, mitochondrial dysfunction, inflammatory responses, and apoptosis in various cell types, along with organ-level concerns like neurodegenerative disease onset when crossing the blood-brain barrier.

A critically important signal in the metadata discovered by the researchers was that measured levels of MNPs tended to be higher in tissues with lesions than in non-lesioned tissues. These included inflamed intestines, fibrotic lungs, or cancerous growths, suggesting a potential link between MNP buildup and local pathology.