The emergence of microplastics as environmental pollutants poses alarming health risks, particularly from orally ingested polyethylene terephthalate microplastics (PET-MPs). A recent study sheds light on how these ubiquitous particles accumulate predominantly in lungs and elicit harmful inflammatory responses.
This research, conducted by teams at the Preclinical Center of the KMEDI hub, examined PET-MPs, which are less than 10 µm and frequently found across ecosystems due to the widespread use of PET products.
Microplastics can originate from industrial applications or form through the breakdown of larger plastic items, including bottles and clothing fibers, and can infiltrate ecosystems, air, and food chains. Serious concerns arise from their accumulation and persistence within biological systems.
The study’s methodology involved feeding ICR (CD-1®) mice with fluorescently labeled PET-MPs to observe biodistribution. The researchers found significant accumulation of PET-MPs within the lungs, evidenced by IVIS spectrum CT analysis and ex vivo imaging of the lung and stomach post-administration. Notably, findings confirmed concentrations of PET-MPs persist over time, with the lungs displaying inflammation associated with different dosage levels.
"PET-MPs are likely to induce an immune response," the researchers state, emphasizing how these particles could trigger detrimental effects within respiratory tissues. Detailed examinations revealed granulomatous inflammation characterized by the presence of immune cells, signaling the body’s response to the retained microplastic particles.
The study revealed notable thresholds of no-observed-adverse-effect levels (NOAEL), determined at 1.75 mg/kg for males and 7 mg/kg for females, delineated through extensive toxicological assessments. These insights point to the concentration-dependent response triggered by microplastics.
This investigation adds to the growing literature emphasizing the need for comprehensive assessments of microplastics, especially as exposure pathways through air and food become clearer. With their small size and chemical properties, PET-MPs can traverse biological barriers, leading to significant health concerns.
The significance of this research cannot be overstated as we grapple with the reality of microplastic pollution. The results challenge the scientific community to devise regulatory standards aimed at safeguarding public health from long-term exposure risks associated with these persistent pollutants.
Overall, as awareness increases surrounding the environmental and health impacts of microplastics, this study forms part of the foundational knowledge necessary for implementing strategies to mitigate their adverse effects.