Task-based Exposure Matrix Toward Evaluating and Identifying Occupational Exposure to Engineered Carbonaceous Nanomaterials

Our current understanding of the ultimate health effects of engineered carbonaceous nanomaterials is limited because exposure assessment, pharmacokinetic, epidemiological, and toxicological studies of these nanomaterials are in the nascent stages of analysis or have not yet been performed. Recent toxicological studies of single wall carbon nanotubes have indicated that long, fibrous nanotubes may exhibit abestiform behavior and cause adverse pulmonary outcomes. However, the estimated exposure to carbonaceous nanomaterials in the workplace is relatively unknown, which complicates assessing risk in the workplace. The objective of this study is to analyze carbonaceous nanomaterial exposure scenarios, to identify knowledge gaps in carbon nanomaterial exposure assessment, and to predict and rank task-specific exposure estimates. The research will involve identifying and defining the processes of carbon nanotube and nanofiber synthesis, characterization, purification, and manipulation during their use and incorporation into products in order to create a specific occupational task exposure matrix. It is expected that the findings from this study will contribute to human exposure estimation during the product lifecycle analysis of carbon nanotubes and nanofibers. In addition, the task exposure matrix will provide important background information for the design of future occupational epidemiology, risk assessment, and environmental exposure studies of nanoparticles.