NORA Manufacturing Sector Strategic Goals
927ZJMG - Carbon Nanotube Dosimetry Modeling for Risk Assessment
Principal Investigator (PI)
Primary Goal Addressed
Secondary Goal Addressed
Attributed to Manufacturing
The purpose of this project is to develop a human respiratory tract deposition model for airborne CNTs to estimate lung dose in workers and assess health risk.
This project is contributing to the NIOSH Nanotechnology Research Center (NTRC) strategic plan by filling key research needs in the critical
The major output is development of a human respiratory tract deposition model for CNTs. The intermediate outputs include the TEM analysis to determine the airborne size distribution of CNTs and the measurement of CNT deposition in a human respiratory cast model. A peer review journal article describing the model development and use will be prepared.
The purpose of this project is to generate the data needed to develop a human respiratory tract deposition model for CNTs, and to develop the model using these data. This project includes three components: (1) Evaluation of transmission electron microscopy (TEM) methods to determine the airborne size distributions of CNTs in the workplace and laboratory; (2) Measurement of CNT deposition in a human respiratory cast model; and (3) Development of a comprehensive human respiratory tract deposition model for airborne CNTs.
The data needed to develop the human lung deposition model (item 3) will be generated by measuring the CNT particle size distributions in air and the deposition fractions in human respiratory casts. The TEM-based quantitative size distribution data (item 1) will be used to determine the equivalent spherical diameter for several classes of CNTs based on size and shape. The fiber-based deposition estimates will be adjusted to account for CNT shape. Validation of the deposition model will be performed using data of CNT deposition in a human respiratory tract cast model (item 2). This project will include external collaboration and contracts. Cross-validation of the model will be performed in collaboration with NIOSH aerosol researchers. The validated model will be disseminated publicly through an existing modeling software platform (e.g., MPPD model).
This project is expected to take 3.5 years to complete, including the time required to develop the contracts, generate the data, and develop the model. Contracts will be developed and awarded in the second half of FY2010 (pending funding). Respiratory cast deposition measurements and TEM data will be analyzed in FY2011. Model development will begin in FY2011 and be completed in FY2013. The findings of this research will be presented at a scientific meeting of aerosol scientists and submitted to a peer-reviewed journal for publication in FY2013.
A critical research need for risk assessment of occupational exposure to carbon nanotubes (CNTs) is to accurately predict the internal dose of CNTs in workers. There are limited data on the airborne exposures to workers and on the aerosol size distributions and characteristics. These data are needed to understand the aerosol behavior and to predict the fraction that is inhaled and deposited in each region of the respiratory tract. There is currently no validated respiratory tract model for CNTs.
To fill these gaps, the purpose of this project is to obtain CNT aerosol data and to develop a biomathematical model to predict the deposition of inhaled carbon nanotubes in the human respiratory tract. The results of this project will be useful in risk assessment of CNT and developing NIOSH recommendations on occupational exposures to nanoparticles.