Health effects of inhaled engineered and incidental nanoparticles

Abstract

Engineered nanoscale materials provide tremendous promise for technological advancements; however, concerns have been raised about whether research of the possible health risks of these nanomaterials is keeping pace with products going to market. Research on nanomaterials, including carbon nanotubes, semiconductor crystals, and other ultrafine particles (i.e., titanium dioxide, quantum dots, iridium) will be examined to illustrate what is currently known or unknown about how particle characteristics (e.g., size, agglomeration, morphology, solubility, surface chemistry) and exposure/dose metrics (e.g., mass, size, surface area) influence the biological fate and toxicity of inhaled nanosized particles. The fact that nanosized particles (1) have a potentially high efficiency for deposition; (2) target both the upper and lower regions of the respiratory tract; (3) are retained in the lungs for a long period of time, and (4) induce more oxidative stress and cause greater inflammatory effects than their fine-sized equivalents suggest a need to study the impact of these particles on the body. Achieving a better understanding of the dynamics at play between particle physicochemistry, transport patterns, and cellular responses in the lungs and other organs will provide a future basis for establishing predictive measures of toxicity or biocompatibility and a framework for assessing potential human health risks.

Keywords::

• Carbon nanotube
• health risk
• nanoparticles
• particle physicochemistry
• pulmonary
• titanium dioxide

Acknowledgements

Background literature research, as presented here, has contributed to conceptual development of original research of the health effects of inhaled carbon nanotubes as funded by US EPA Star Grant R831714 and Student Fellowship for University of California Toxic Substances Research & Teaching Program to the University of California, Davis. Underlying research is also supported in part by US EPA grants R832414 and R82215, and NIOSH grant 0H07550 to the University of California, Davis. The authors prepared this manuscript under the above noted grants, as well as during the normal course of employment by ChemRisk, LLC (A.M.) and the University of California, Davis (A.M., K.P.). The authors have sole responsibility for the writing and content of the paper. The contents of this review may not necessarily reflect the views of the funding organizations. None of the authors has a financial relationship with a commercial that has an interest in the subject of this manuscript.