Polystyrene Microplastics Linked to Thyroid Dysfunction in Mice

Research conducted by scientists at Hajee Mohammad Danesh Science and Technology University in Dinajpur, Bangladesh, has uncovered significant evidence of the toxic effects of polystyrene microplastics (PS-MPs) on thyroid function in mice. The study, published in Veterinary Medicine and Science, found that exposure to PS-MPs led to substantial increases in calcium, thyroxin, free T3, and free T4 levels, alongside elevated oxidative stress markers and abnormal thyroid follicle development. Gene expression analysis revealed a marked reduction in thyroid-stimulating hormone receptor (TSHR) and thyroid peroxidase (TPO) levels in PS-MPs treated groups, indicating thyroid dysfunction.

Key Takeaways:

• Polystyrene microplastics (PS-MPs) have been found to disrupt endocrine function, particularly affecting the thyroid gland, in mice.
• Exposure to PS-MPs led to significant increases in calcium, thyroxin, free T3, and free T4 levels in mice.
• The study found that PS-MPs exposure led to abnormal thyroid follicle development, colloid loss, hemorrhage, and necrosis in mice.
• Gene expression analysis revealed a marked reduction in thyroid-stimulating hormone receptor (TSHR) and thyroid peroxidase (TPO) levels in PS-MPs treated groups, indicating thyroid dysfunction.
• The study suggests that environmental contamination by PS-MPs may lead to an increase in endocrine disorders linked to thyroid health in veterinary species.
• Further research and preventive measures are necessary to mitigate the potential risks posed by PS-MPs to thyroid health.

Statistics:

• 60 male Swiss albino mice were used in the study, divided into three groups: a control group and two treatment groups receiving 0.1 mg and 0.2 mg PS-MPs via oral gavage for 28 days.
• Biochemical tests, including catalase, superoxide dismutase, reactive oxygen species, and hormone levels, showed significant increases in PS-MPs treated groups.
• Histopathology and gene expression analysis revealed abnormal thyroid follicle development and gene expression changes in PS-MPs treated groups.
• The study found that PS-MPs exposure led to significant changes in thyroid function, including a decrease in thyroid-stimulating hormone (TSH) and calcitonin levels.

Sources:

• "Polystyrene Microplastics-Induced Thyroid Dysfunction in Mice: A Study of Gene Expression, Oxidative Stress, and Histopathological Changes" (2025;11(3)).
• Wiley, 111 River St, Hoboken, NJ 07030, USA (publisher contact information).
• Md Kamruzzaman, Dept. of Dairy and Poultry Science, Faculty of Veterinary and Animal Science, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh (corresponding author).
• Additional authors: Md Sadequl Islam and Umme Kulsum Rima.