Jayanta Gupta

Carbon nanomaterials (CNMs) particularly carbon nanotubes (CNTs) have found widespread applications in diversified fields including biomedical, industrial, and agriculture sectors, because of their unique physicochemical attributes. However, these high-volume nanomaterials have the propensity to become airborne as carbon nanoparticles (CNPs) during manufacturing, handling, and usage and pose exposure hazards in occupational and nonoccupational settings. Consequently, CNPs are deemed as emerging members of the toxic particulate matter in air pollution. Animal model studies have shown that inhaled CNPs have the potential to cause respiratory (tissue injury, inflammation, fibrosis) and systemic health effects including various organ toxicities and gut dysbiosis; the respiratory effects have been corroborated in emerging human epidemiological studies in CNM-exposed individuals. Inhaled CNT nanoparticles have been shown to cause immunotoxicity, oxidative stress, DNA damage, and other cellular changes, though the specific underlying molecular mechanisms continue to emerge. In this direction, we have compared the available Omics-based studies and presented an account of adverse outcome pathways (AOPs) impacted by CNT exposures. In particular, activation of specific immune signaling pathways varies with the CNT particle type/shape (rods versus tangles), as well as exposure duration. In conclusion, while CNMs offer significant benefits across various fields, their propensity to become airborne posing exposure risks via air pollution and health consequences must not be overlooked. Continued research is crucial to fully understand the underlying molecular mechanisms of their health effects and to develop effective strategies for safe handling and use.