"Carcinogenicity: Certain multi-walled carbon nanotubes (MWCNTs), specifically the straight, rigid MWCNT-7 (Mitsui-7) variety, are classified by the International Agency for Research on Cancer (IARC) as Group 2B (possibly carcinogenic to humans).

Mesothelioma: Long, rigid, needle-like CNTs can cause "frustrated phagocytosis," where macrophages are unable to engulf the fibers, leading to chronic inflammation, fibrosis, and mesothelioma-like growth in animal models.

Respiratory Damage: Inhalation exposure in rodents has consistently shown the development of pulmonary inflammation, granulomas (clumps of immune cells), and irreversible lung fibrosis (scarring).

Organ Toxicity: Beyond the lungs, studies have indicated potential toxic effects on other systems if CNTs enter the bloodstream or are ingested:

Liver: Can cause hepatocyte damage and oxidative stress.

Cardiovascular: Exposure has been linked to hypertension, heart rate changes, and increased plaque formation in animal models.

Neurological: Some types may cross the blood-brain barrier, potentially causing neuroinflammation."